Alumni

Daan van der Veldt (BSc) – Analysing continuous decent operations Eindhoven.

A continuous descent operations follows, unlike traditional step-down approaches where aircraft descend in a series of level segments, a smooth, uninterrupted descent from cruise altitude to the runway threshold. Continuous Descent Operations offer several advantages, including improved fuel efficiency, noise reduction, better air traffic management, increased safety, and potential cost savings. These benefits make CDO an attractive practice for airlines and aviation authorities looking to improve the sustainability and efficiency of air travel.

This research is tasked with creating a CDO definition for the airport of Eindhoven. Using flight data sourced from radar information, the CDO efficiency is analysed, resulting in CDO performance statistics and deviations. Also, correlated factors into CDO performance are researched. Finally, these factors and potential improvements of these factors are investigated.

Graduated: June 2023

Sven Vegter (BSc) – Tactical flight planning to enhance runway load balancing. 

Traffic entering AMS-FIR usually presents itself at the FIR-entry points according to their filed flight plan.

AMS-FIR has a relatively high density and complexity of traffic. Therefore, rerouting arriving aircraft inside this airspace to make an approach to a runway, other than the one most conveniently oriented with respect to their FIR-entry point, is considered undesirable. This research will provide insight into a proposed operational tool which could help LVNL improve its operation. This tool will be referred to as Tactical Demand Tailoring (TDT) in this report. It would allow LVNL to redirect the flights arriving to Schiphol tactically, after their departure, but before these aircraft enters AMS-FIR. This extends the influence LVNL has over Schiphol arrivals to outside of its area of operations.

Graduated: June 2023

Stijn Brunia (MSc) – Predicting controller workload within individual ground control sectors.

At Schiphol airport all ground traffic is handled by ground controllers, who are all working on the traffic within a specific geographical sector. There are four main sectors, but one controller can also handle multiple different sectors. This means that the number of active controller will fluctuate during the day. There is however little insight in what the workload of a specific sector will be within the nearby future. Next to this there is also little insight in how the workload of the Schiphol ground controllers effects the capacity of the taxi system as a whole. Since the taxi system capacity has a large influence on the capacity for Schiphol as a whole, more insight within the parameter of ground controller workload could be of significant use, as it can be used in deciding on what number of controller will need to be active.  This research will try to create a tool in which the upcoming workload can be estimated using the planned operational data.

Graduated: July 2023

Robbert Boelhouwer (MSc) – Valdidation noise model sonAir at Schiphol

Aircraft noise is a significant problem for communities surrounding airports. Accurate prediction models are needed to estimate noise levels from aircraft operations. In this research, the accuracy of the sonAIR aircraft noise model is evaluated in predicting noise levels around Schiphol airport by comparison to measurement data from NOMOS and the current best practice modelling approach Doc29. Results show a significant but consistent underestimation of noise levels by sonAIR, mainly due to a generalisation of emission models. This research contributes to better aircraft noise predictions, which will have implications ultimately leading to a better quality of life for communities affected by aircraft noise.

Graduated: May 2023

Stijn van Selling (MSc) – Supporting Time-Based Separation and Merging in Approach Control.

Aviation as a whole is expected to grow, therefore adjustments to the current air traffic management system will need to be made. Part of these adjustments is the switch from distance-based separation to time-based separation. This will allow the airport capacity to increase when strong headwinds are present on the active runway. An increase in runway capacity will also result in less holding time required as more aircraft can land in the same amount of time, hence saving fuel and thus making for a more environment friendly operation. In order to facilitate time-based separation, the air traffic controller will need assistance in terms of decision support tools as time-based separation is not easily visualised on a 2D map. This research will thus try to design, implement and test such a decision support tool in order to support time-based separation in approach control.

Graduated: April 2023

Eneko Rodríguez (MSc) – Investigating the effects of Flexible Use of Airspace availability and plannability on fuel efficiency

All military airspace in the Amsterdam Flight Information Region (FIR) falls under the concept of Flexible Use of Airspace (FUA), which no longer considers airspace as purely ‘civil’ or ‘military’ but rather as a continuum to be allocated temporarily according to user requirements. The complexity of FUA lies in the challenge to harmonize the airspace usage according to these requirements, which largely contradict one another. On the one hand, the military user benefits from using the airspace flexibly, as the effectiveness of their missions and exercises depend on the availability of weather and equipment conditions. On the other hand, the civil users benefit from a high plannability to efficiently execute their operations. By modeling the fuel consumption of civil traffic, the effects of availability and plannability of the FUA in Amsterdam FIR can be computed. While FUA availability determines the route followed by a flight, FUA plannability determines how early the true trajectory is known. Announcing the FUA usage earlier results in avoiding to carry a surplus fuel, which increases the weight and thus fuel burnt of the aircraft. By understanding these effects, new guidelines of FUA usage and plannability may be proposed in the context of the ongoing Dutch Airspace Redesign Programme.

Graduated: August 2022

Bart Rozendaal (MSc) – A neural network approach in optimising
airport strategy with trajectory prediction

As the airspace is getting increasingly crowded worldwide, the capacity management of airports is more important than ever. To avoid unnecessary and costly delays, it is crucial for airports to have well timed strategies and reliable arrival predictions. To achieve this, airports need accurate long-term trajectory predictions such that arrival times can be estimated with high precision. Countless factors such as weather conditions, restricted fly areas and air traffic control clearances cause route uncertainties, making it difficult to predict long-term trajectories accurately. In this thesis, a bidirectional LSTM recurrent neural network is proposed to solve a sequence-to-sequence learning problem and predict the most likely route flown by the aircraft before take off. The network is trained on historical flight plans only, making it easy to implement. The data exists of incoming flights on Schiphol international airport within Europe. Different Hyperparameters are tested to improve performance of the network.

Graduated: July 2022

Thomas Vermeulen (MSc) – Evaluation and assessment of the performance of the KNMI Schiphol Kansverwachting (SKV) for Mainport Schiphol with respect to wind direction and wind gusts

Accurate weather forecasts are crucial information to regulate the operations at Schiphol Airport. Sudden changes in weather conditions need to be communicated in a fast and efficient way to maintain the safety and efficiency for flight operations. KNMI provides a probabilistic weather forecast, called the Schiphol Kansverwachting (SKV), which is produced using output of numerical weather prediction models in combination with the latest observations and several statistical post-processing tools. In particular information on the wind direction and the wind gusts is highly important to support air traffic control. Relatively large errors could lead to restrictions which were in the end not needed or it could lead to restrictions which were issued too late. This research will evaluate the performance of the SKV of wind direction and wind gusts for three different weather models: HIRLAM, HARMONIE and ECMWF. Quantitative information on the forecasting errors will be identified, but also suggestions for possible improvements on the weather forecasts will be part of the result of this study.

Graduated: July 2022

Wesley Vork (BSc) – Develop sequential steps towards a Multi Airport System (MAS)

Dutch airports have grown significantly over the years. This growth is occurring almost autonomously. No mechanisms have been put in place to strategically balance this growth between Dutch airports, routes, or airspace. Without major reforms, the maximum capacity of the airspace will soon be reached. The relationship between EHLE, EHEH, EHRD and EHAM is under scrutiny. With autonomous growth and without mitigating measures, this will lead to the first airspace bottlenecks in 2023 and contiguous bottlenecks in 2035. By examining how air traffic can be better handled through joint air traffic management, the capacity bottlenecks can be addressed. By conducting a thorough research on the MAS, it will become clear what problem the MAS solves and how this system can be used to solve the capacity bottlenecks.

Graduated: July 2022

Max Aalberse (MSc) – Optimizing the distribution of aircraft over the IAF

Around Schiphol and many other airports the amount of movements allowed is constrained due to the considerable noise pollution from aircraft. For a large part the noise pollution is created by arriving aircraft that are in between the IAF and the RWY. During this period the aircraft are in so called transition. These transition routes are usually already optimized to reduce the noise disturbance to surrounding residents, but due to the positioning of the runways this is not always possible. A different distribution of the aircraft over the IAF could result in less noise disturbance for surrounding residents, but would also increase flight times and fuel usage and therefore an increase in other emissions such as CO₂. The goal of this research is to create a parameterized model that optimally distributes the aircraft over the IAF based on a quantitative trade-off between noise disturbance and CO₂ emissions. Resulting in a model that is potentially able to reduce noise disturbance around airports while keeping the increase in environmental impact at a minimum.

Graduated: June 2022

Edzer Oosterhof (MSc) – Effect of Trajectory Prediction Uncertainty on Debunching of Inbound Air Traffic

With the current growth in air traffic and the resulting developments in terms of environmental issues and noise abatement, the pressure on the Area Control Center (ACC) is growing. On the one hand the Terminal Control Area (TMA) requires arriving traffic to be handed over accurately sequenced and merged, and on the other hand the ACC tries to minimize the miles flown in its sector. At the tactical level, there are Air Traffic Flow Management (ATFM) measures in place for traffic within Europe. However, no such tactical measures exist for traffic from the North Atlantic Tracks, increasing the probability that bunching occurs in the ACC during peak loads. By tactically predicting bunching in the sector and at the Initial Approach Fixes, a concept for debunching should be devised that focusses on airborne delay consumption and sequencing of traffic in the Upper control Areas (UTA) before it enters the Control Area (ACC), decreasing the pressure on the ACC.

Graduated: March 2022

Rebekka van der Grift (MSc) – Aircraft Noise Model Improvement by Calibration of Noise-Power-Distance Values Using Acoustic Measurements

The impact of the aircraft industry on the environment becomes more evident every day. Especially for local communities around the airport, the noise nuisance is an important factor which puts a strain on the capacity of Schiphol mainport. This capacity is based on the noise levels around airports, which are calculated with noise models based of key input parameters. The accuracy of these models is thus of great importance for the Schiphol mainport and the local communities. This research aims to develop a dynamic noise model based on real world aircraft noise measurements taken by NOMOS. The measurements will be used to calibrate certain input parameters to minimise any differences between model and measurements. This method helps to keep the model up to date and validated. Using measurements instead of standard input parameters is expected to increase the accuracy of the model, but also increase the trust of local communities in noise modelling.

Graduated: January 2022

Stephanie Wiechers (MSc) – Design and Evaluation of a Support Tool for Planning Adherence While Holding Inbound Air Traffic

As Schiphol is one of the busiest airport in the world, with tight flight schedules and urban areas that lie under arrival routes, adherence to the time planning is very important. When extreme weather conditions cause delays over the entire arriving fleet, holding stacks are installed at the three Initial Approach Fixes (IAFs) around Schiphol. In the current operational environment, little support is offered to the holding stack controller (ACC) to gain an overview of the effects of speed and wind on the turn times and difference between inbound and outbound leg velocity. With increased support, the controller will be able to make decisions based on representative information and with that, deliver inbound aircraft to Approach (APP). The (expected) resulting increased EAT adherence should lead to more orderly traffic in the TMA, improving capacity and workload.

Graduated: December 2021

Soraya van Beek (MSc) – Improving probabilities of poor visibility and ceiling

In order to optimize the current Schiphol operations, an accurate weather forecast is of great importance. The Royal Netherlands Meteorological Institute (KNMI) provides a probabilistic weather forecast for Low Visibility Procedures (LVPs) to Schiphol, which is computed using deterministic weather models. If these LVPs occur due to low visibility or low ceiling, adjusted capacity and flow restriction are needed within airport operations. Inaccurate forecasting can lead to last-minute restrictions or restrictions when not needed. This research will assess the performance of the probabilistic forecast of visibility and ceiling at Schiphol airport. This will be done for the performance of three different weather models: HIRLAM, HARMONIE and ECMWF. Causes for inaccurate forecasting will be identified and suggestions for improvement of the probabilistic weather forecast will be the end result of this research.

Graduated: October 2021

Gijs Bekkers (BSc) – Improving Operational Plan Preparation for Amsterdam Airport Schiphol

Stakeholder preparation for future operation is currently carried out mostly individually, with limited and mostly untimely access to relevant information. Through identifying and mapping plan development for each involved actor, it is possible to find commonalities and moments of information exchange. Data that could be of relevance for others is often kept private, due to lack of insight in handling by others and lack of knowledge on collective benefits of information-sharing. Using feedback from the Airport’s Operation Centre (APOC) on their Airport Operations Plan (AOP), and from LVNL on their OPS plan, together with expert recommendations, poses improvements for desired information sharing within stakeholders. Optimizing the plan-establishment processes and collectively arranging operational preparation yields benefits for all involved stakeholders. To finally ensure proper execution, data-exchange and arrangements should be constantly monitored using chosen performance indicators.

Graduated: June 2021

Janjaap Wijnker (BSc) – Evaluating the accuracy of information provided by the (D-1) OPS plan

In early 2020 LVNL implemented the OPS plan with the objective to improve the alignment of traffic demand with available capacity. This can be achieved by improving the predictability of the operations and make this transparent and accessible for the stake-holders. Every day the PRE-TACT unit develops an OPS plan for the following operational day. The plan contains two types of information, external factors that might impact the capacity, and recommendations for the most optimal operations. The recommendations are based on the external factors, for example the predicted traffic demand and weather forecast. These two factors contribute to the configuration of runways, and the runway selection determines the required capacity. In order to for LVNL to improve possible deficiencies of the OPS plan, the aim of this research study is to evaluate the accuracy and precision of the predicted traffic demand. The analysis focusses on the difference between predicted and actual traffic demand on a 20 minute resolution. In addition, the implications of factors contributing to the proposed runway configuration will be assessed since the use of different runways could have a significant impact on the capacity.

Graduated: June 2021

Christophe Vakaet (MSc) – Taxi Time Prediction with Classical and Auto Machine Learning at Schiphol Airport

Ground control uses the Departure Sequence Planner (DSP) to optimally plan departures within the operational constraints. The DSP uses an estimated Variable Taxi Time (VTT) to calculate an aircraft’s Target Take-Off Time (TTOT). If the VTT is underestimated flights will not make the determined TTOT, while an overestimation requires the air traffic controller to tactically hold an aircraft. These consequences result in delays, capacity losses, additional workload, and uncertainty. This uncertainty inhibits further operational optimizations. The VTT is currently predicted based on the average taxi times for different gate-runway combinations, wake turbulence categories, deicing procedure, and simplified runway configuration. The goal of this project is to improve VTT predictions by employing machine learning techniques and additional data sources such as traffic density, weather, aircraft type, and more.

Graduated: June 2021

Mathijs Post (MSc) – Air Traffic Flow Management for Amsterdam Airport Schiphol

Air Traffic Flow Management is a measure to optimize the flow of traffic in the European air transportation system. Flights are planned such that these can be operated with as little delay as possible. However, on the day of operation many changes can still happen. Amsterdam Airport Schiphol is the biggest contributor to Airport ATFM Delay in Europe, meaning many flights are delayed because of congestion or other airport related reasons at Schiphol. Besides Airport ATFM Delay, the arrival punctuality of flights at Schiphol can be improved. More insights into the causes and interactions of operational parameters is necessary to understand the main contributors for Airport ATFM Delay and arrival delay. A Bayesian Network is proposed, which is a Probabilistic Graph Model that can find interactions between variables and can identify the operational conditions leading to Airport ATFM Delay and arrival delay.

Graduated: June 2021

Bart Bouwels (MSc) – Air Traffic Management Concept for Off-Idle Continuous Descent Operations at Schiphol

Due to the continued growth of the aviation industry, emission and noise production are at an all-time high. In order to reduce this, conventional approaches could be replaced by continuous descent approaches (CDA). These eliminate all level segments, greatly reducing the average thrust setting, resulting in large reductions in noise and emission production. The problem with almost all CDA procedures is that it makes it much more difficult to predict the future position of an aircraft since it flies its own optimal descent profile, with zero thrust. This results in a need for more separation, greatly reducing the airport capacity. This can largely be solved by using a fixed, constant descent angle for all aircraft. Assessing the robustness of such a concept for a high capacity airport is therefore an important stepping stone towards actual implementation.

Graduated: May 2021

Brian Verhoeven (MSc) – Improving the predictability of Aircraft Induced Lightning (AIL) for Mainport Schiphol

Lightning strikes to aircraft are not uncommon in aviation. Although they are not dangerous anymore, they can still result in damages to the aircraft and delay airline operations. Passengers can get scared from the lightning strike as well. Especially in the region around Amsterdam Schiphol Airport, AIL can occur during fall and winter as well. Estimations are that 90% of the lightning strikes are a result of the aircraft triggering a lightning strike, rather than being accidentally struck. In order to prevent as many strikes as possible, it is thus key to understand this process. Therefore, this research aimed to gain a as complete as possible understanding of the process of AIL and use this knowledge to supply new information about AIL to pilots, as AIL is not included in most standard pilot trainings. This can allow pilots to become more aware of AIL and prevent more lightning strikes and the corresponding inconveniences from occuring.

Finished internship: January 2021

Jeanette Derks (MSc) – Coordinated Arrival and Departure Management for Dependent Runway Operations

The foreseen increase in air traffic movements in combination with eased separation minima between aircraft, redefined by the International Civil Aviation Organization (ICAO) in 2015, is expected to emphasize current runway dependencies at airports even further. As the number of aircraft in vicinity of an airport will increase, conflicting flight paths between arriving aircraft and departing aircraft will become a bigger safety hazard and will affect the efficiency of both the arrival and departure traffic flow. Airports that rely on dependent runways in their daily operation await serious congestion problems if no coordination between arrival and departure management will be initiated soon. Therefore, this research aimed to increase runway configuration capacity at airports that experience interference between arrival and departure capacity due to the use of dependent arrival and departure runways by developing and exploring multiple concepts for a coordination mechanism between Arrival and Departure Management.

Graduated: November 2020

Robin Vervaat (MSc) – Priority-based flight scheduling in the tactical phase

Years of growth in air travel have meant that, as usage is nearing current capacity, delays are becoming virtually inevitable for air carriers operating in our airspace. Flight delays have a significant impact on airport and airline operations, as well as their cost. As such, tactical planning of the flights has become increasingly important, especially for a hub-operator with many connecting passengers. In collaboration with LVNL, KLM and Amsterdam Airport Schiphol, a novel model is being investigated tasked with the Arrival Sequencing and Scheduling of flights considering (airline) priority criteria. Smarter use is to be made of the available infrastructure in order to increase capacity and decrease delay (costs), however, fairness and equality between stakeholders will still need to be upheld.

Graduated: September 2020

Bas Timmer (BSc) – Analysing inbound sources of information to improve the predictability and accuracy of the landing times

With the growing aviation industry in Europe, efficient use of the inbound capacity becomes even more important. One of the determining factors in capacity is the ability of accurately predict the landing time of aircraft. LVNL systems AAA and ASAP generate their inbound sequence planning based on Estimated Landing Times (ELDT) calculated from a variety of data sources. When CDM was implemented, business rules were put in place to prioritize certain data sources above another based on quality and accuracy. Nowadays, the quality and accuracy of these sources are thought to be different. Reviewing the current business rules is done by analyzing the quality and accuracy of the data sources, and how flight characteristics or procedures can influence the accuracy of the ELDT.

Graduated: August 2020

Max (MSc) – Aircraft noise model validation using noise measurement feedback

One of the current factors limiting the growth of the aviation industry in the Netherlands is the relationship between the aviation sector and local communities around airports. Aircraft noise production is one of the main causes of nuisance in residential areas reported by RIVM. It is therefore, for the aviation industry as a whole, of great importance to gain a better understanding of the methodology of aircraft noise modelling and make improvements on this modelling process if deficiencies in the current model are detected. The validation of the aircraft noise model, using noise measurements taken around the airport, is crucial for the scientific foundation of the model. This scientific foundation is expected to increase the transparency in how noise calculations are performed, which increases community trust in the aviation industry as a whole.

Graduated: July 2020

Ashley Scheenloop (BSc) – Impact of the fleet mix on the outbound capacity at Schiphol Airport

With the future growth in amount of flight movements in the aviation sector, efficient use of the airport resources are getting more and more important. In 2019 it was seen that the declared runway capacity at Schiphol airport is not reached during the outbound peaks. Previous research showed that the aircraft type (Wake turbulence category) influences the runway capacity. With the use the A-CDM principle, the outbound phase at Schiphol airport is analysed. This way the time spent, between the time references (A-CDM Milestones), for each Wake turbulence category is analysed and compared. This will provide an insight on the behaviour of these aircraft types, and indicates a possible significant difference/bottleneck. Besides the active runway combinations are analysed during these outbound peaks.

Graduated: July 2020

Marc Out (BSc) – Reducing the fluctuations on the outbound planning at Amsterdam Airport Schiphol

At Amsterdam Airport Schiphol, the outbound planning is created by the Collaborative Pre-Departure Sequence Planner (CPDSP). Currently, this outbound planning is fluctuating because of frequent updates of the Target Off-Blocks Time (TOBT). Having a dynamical outbound planning could create in a loss of valuable outbound capacity and increasing the risks in regulated flights by EUROCONTROL. To reduce the occurrence of frequent TOBT updates, different business rules have been analyzed for the auto-TOBT update mechanism. This mechanism updates the Target Off-Blocks Time automatically once the inbound flight has an assigned landing runway until the moment the aircraft is in-blocks or the Main Ground Handler updated the TOBT manually. The analyzed business rules had different characteristics related to the frequency of TOBT updates and the accuracy of this target time. Those two main characteristics were required to analyze to be able to have an overview which business rule creates less updates but having the same quality as in the current situation.

Graduated: July 2020

Thijs Scheffers (BSc) – Improving the outbound planning process at Amsterdam Airport Schiphol

To improve the outbound planning process of Schiphol Airport, the frequency, availability and accuracy of Estimated Landing Time (ELDT) data has been investigated. Special attention is placed on the information sharing and the calculation of the ELDT, that is calculated by Amsterdam Advanced Air traffic control system (AAA). In addition, the search for new and accurate data sources to estimate the landing time is a continuous effort. As of November, 2018, a new arrival management (AMAN) system is in use at LVNL, called Advanced Schiphol Arrival Planner (ASAP), which replaces the old arrival system, called Inbound Planning (IBP). The new AMAN has implemented different internal characteristics and processes, such as a new trajectory predictor and planning algorithm. Therefore, the new AMAN could potentially provide more accurate arrival time predictions. Both systems are compared to identify their performance.

Graduated: April 2020

Matthijs Ottenhoff (MSc) – Wind and Trajectory Uncertainty in a 4D Trajectory Management Interface

With air traffic numbers increasing, a shift in the Air Traffic Management system towards 4D flight plans, where an aircraft trajectory is pre-planned in both time and space, is foreseen. When these pre-planned trajectories are subsequently executed, unforeseen airspace perturbations, such as weather, sequencing and changing airspace constraints, will inevitably require small changes in the trajectories to be made by the air traffic controller. This perturbation management control task will consist of ensuring a safe airspace while adhering to the strict time constraints imposed by the 4D flight plan. In collaboration with LVNL, a decision support interface was designed and evaluated with the aim of visualizing possible conflict resolutions in the 4D domain. A special focus was put on the integration of wind and trajectory uncertainty information into the interface.

Graduated: March 2020

Eline Bakker (MSc) – Design and Evaluation of a Visual Interface for an En-Route Air Traffic Control Merging Task

In the past decades, the air traffic growth has resulted in increasingly complex situations involving more aircraft simultaneously. In order to guarantee safety is maintained within the increasingly crowded airspace, new solutions are expected. In collaboration with the LVNL, an Inbound Traffic Support System interface was developed. The goal of the interface is to visualize the possible solutions of an area controller’s task of merging aircraft towards a restricted waypoint in the current work domain, such that the impact of decisions made can be foreseen.  By showing the affordances of the work domain, the display keeps the air traffic controller as the active decision maker rather than issuing advisories.

Graduated: October 2019 

Femke Mollema (BSc) – Creating more capacity at Amsterdam Airport Schiphol by reducing planning inefficiencies amongst KLM, LVNL and AAS

As of today, the aviation parties at Amsterdam Airport Schiphol are connected to the European network managed by Eurocontrol NMOC (Network Manager Operation Centre) through its local Airport CDM (Collaborative Decision Making) process. Within the Dutch aviation industry, many stakeholders are involved in the air traffic process, of which three of the main stakeholders are KLM, AAS and the LVNL. Each stakeholder can influence a certain part of the air traffic process, for which they create their own planning. Other parts of the air traffic process, over which a stakeholder has no control, are influenced, and planned on, by the remaining stakeholders. Since the air traffic process is a continuous cycle all stakeholders involved carry dependencies on one another, which also influences the planning each stakeholder makes. To succeed both the overall air traffic process and thus the stakeholders’ individual process, a collaboration among stakeholders is required. The goal of this research is to determine which planning inefficiencies may arise as a result of the different points of interests of the stakeholders within the Dutch aviation sector. By determining these inefficiencies, it can be researched how these can be eliminated, which could eventually benefit the capacity problem. For the purpose of this research the focus will primarily be on KLM flights.

Graduated: August 2019

Sybren Kuiper (BSc) – Evaluation of plan stability deviations in the flow at Schiphol airport

Over the last years Schiphol has experienced a growth in aircraft movements and exchange of narrow body aircraft for wide body aircraft. The infrastructure has been unable to change at the same pace increasing the pressure on the ground operations capacity and forcing the growth into the off-peaks moments where free infrastructural capacity was available. By growing in the off peaks a new challenge arose. The unused capacity was of essential value in the system plan stability. It offered flexibility that could be used to recuperate from planning deviations. The situation created, can cause a deviation from the plan to trigger a domino through the day that cannot be halted because there is no recuperation space. To stop this effect, it is essential to perform research into the current situation of the plan stability, and the exact causes that start or continue the domino effect. To do this the research will answer the following research question: “What are the opportunities for Amsterdam Airport Schiphol and the other KDC stakeholders to improve the airside ground operational plan stability of the airport?”

Graduated: August 2019

Kyara Metz (BSc) – Evaluation of peak hour capacity at Schiphol and similar airports to determine common capacity management practices

According to EUROCONTROL, Schiphol has the most significant contribution on global ATFM airport delays of all the European Airports; weather and airport capacity were targeted as primary cause of delays. Therefore, this research investigates the potential uses of holding buffers of inbound flows at Amsterdam Schiphol Airport (AAS) during peak hour of operations to absorb delays; special attention is placed on analysing the current methods employed by Schiphol and other Airports uses holding buffer not as a reactive resource for ATCs but a everyday use tool to maximize throughput on runway.

Both quantitative and qualitative research has been used to investigate which operational possibilities LVNL has to buffer inbound traffic in the Dutch airspace and to what extent these buffers can be used in managing the operational inbound peak capacity. To determine the current linear buffer capacity, 20,000 flights from July 2018 were analysed.

Graduated: August 2019

Davey Hooijmeijer (MSc) – Schiphol noise analysis for fixed arrival routings 

In this thesis research, dutch aircraft noise model (NRM) calculations are compared to measurements to analyse the aircraft classification used in the model. To do so, a new implementation of the model has been set up to calculate with LVNL trackdata and NOMOS measurement data. First, the classification approach is analysed as prescribed, which shows clustering of aircraft types when compared to measurements. After, the theoretical input data as prescribed for the model is assessed and replaced by real data for each type specific. This leads to improvements of the model calculations when compared to measurements and shows that aircraft-specific flight-information would improve the model significantly. Concluding, it is shown that aircraft noise models strongly rely on the quality of the input data. Current input data shows certain mismatches with respect to reality, resulting in differences between calculations and measurements. However, the calculations can give valuable insights in the effect of operations on the overall noise exposure.

Graduated: July 2019

Anouk Hollebeek (BSc) – Evaluation of AMAN implementation to establish improvements in the arrival efficiency

A new Arrival Management system, called Advanced Schiphol Arrival Planner (ASAP), was implemented in 2018 to regulate the arrival traffic flows at Amsterdam Schiphol Airport (AAS). ASAP aims to be an assisting support tool for the Approach Planner (APLN)  to monitor and safety merge inbound traffic flows in the Dutch Terminal Control Area (TMA). To validate the implementation of ASAP diverse analysis have been run. This work describes some recent insights and findings regarding the performance and interaction between users (ATCs) and ASAP. Particular attention is placed to establish the moment and type of interaction between the different users. The performance of the tool was evaluated using four main performance indicators; Expected Approach Time (EAT) adherence, slot adherence, holding ratio, influence of APLN.

Graduated: July 2019

Flore Wassenberg (BSc) – D-1 process impact evaluation

In 2018, it was started as part of the development of the capacity management function was the D-1 project. The D-1 project intends to provide an operational and capacity plan before the day of operation. Within the D-1 project team there is a need to validate the quality of the predicted traffic demand, because the prediction generated was not quantitatively evaluated afterward. To explore the reliability and usability of the traffic demand prediction at D-1, a bachelor thesis research has been performed. This research has been done by means of comparing the D-1 traffic demand prediction with the demand on the day of operation. The last submitted flight plans at D0 have been compared to the data predicted on D-1. The sample used contains data that was generated during a period of three months of the D-1 project trial. The research concludes that the traffic demand prediction is for parts not accurate enough to support the D-1 decision making process.

Graduated: July 2019

Casper Moll (BSc) – Capacity analysis of airport slot planning and air traffic demand

According to Eurocontrol,  in 2017 Schiphol Airport was the airport with the biggest inbound ATFM delay of all major airports in Europe. One of the reasons that could cause the inbound ATFM delay is the so called ‘bunching’ effect at the border of the Dutch airspace. The objective of this research is to determine if the encountered planned bunches at -3-hour planning phase has an impact on the airport slot planning. This research focusses on the airport slot declaration and the planned demand based on the last filed flight plans, covering a period from the 25th of October 2017 till the 27th of October 2018. The analysis  contains 254,000 arriving flights in both winter and summer season. The analysis determines to which extent the bunching occurs in the airport slot declaration, and at the border of the Dutch airspace. The results reveal that bunching are present in the pre-planning phase within the airport slot declaration and is caused by the skewness within the airport slot-brackets. The analyses render similar patterns in which overdemand occurs within the time-brackets. The subsequent relationship between the airport slot planning and air traffic demand is around 48%, within the assumptions and limitations of the research. This means that 48% of the flights which are planned in a period with overdemand within the airport slot allocation, also tend to arrive in a period with overdemand at the border of the the Dutch airspace.

Graduated: June 2019

Marc Riebeek (BSc) – Comparison of airport slots and schedule & flight planning

Amsterdam Airport Schiphol is the airport with the most airport Air Traffic Flow Management (ATFM) delay in Europe in 2017. One of the causes of the ATFM delay is that airlines do not adhere to their allocated airport slots. With providing insights into deviation between flight schedules or flight plan and airport slot, causes of deviating to the airport slot are identified. This research is done by means of analysing the deviations to identify the characteristics of the deviations. In addition, interviews with airlines and a ground handler and literature about possible causes are used to provide insights. The main findings are that ~ 3.3% of the flight schedules deviate from the airport slot. The deviation between flight plan and airport slot is around 67% of arriving flights. This deviation of flight plans means that the estimated in block time (EIBT), deviates more than 5 minutes from the airport slot. Both in absolute amount and relative percentage, general aviation and cargo airlines are the business models that cause the most deviation between flight schedule and airport slot. An agreement between the general aviation ground handlers and the typical business of cargo are the main reasons for the deviation. The full-service carriers and low-cost carriers cause in absolute number, the most deviation between the EIBT based on flight plan and airport slots. If the EIBT, based on the flight plan, is earlier than the airport slot, more than 90% of these arrivals are planned earlier because of schedule buffers.

Graduated: June 2019

Mats Dirkzwager (MSc) – Design and Evaluation of a Visual Interface for Separation Support in Time-Based Approach Air Traffic Control

On final approach, an Approach (APP) Air Traffic Controller (ATCo) is responsible for keeping sufficient separation between aircraft lining up on the ILS. The current industry standard is to separate these aircraft with a minimum distance, called Distance-Based Separation or DBS. European regulation requires all European airports to implement separation based on time (TBS) before 2024. Due to this implementation, effectively changing the APP ATC task from a geometrical to a time-based problem, and because of further complications such as the European Re-categorisation of aircraft types, experts fear that the theoretical gains attainable by using TBS will not be fully realised. In this research, a display tool concept to aid APP ATCos in realising the full potential of TBS, the Ideal Turn-In Point (ITIP) display is designed and evaluated with respect to the current state of the art. The ITIP display assists controllers in selecting optimal approach strategies starting from the moment aircraft enter the Terminal Control Area. The display aims to assist the operator by showing the possibilities and restrictions in the system rather than giving (restricting) advisories. In an initial proof-of-concept experiment, comparing the ITIP display to the current industry state of the art display, promising results were found; the ITIP display was shown to maintain safety and increase efficiency, whilst maintaining controller workload. The current industry state of the art display is a tool designed by the National Air Traffic Services, currently operational at London Heathrow Airport.

Graduated: June 2019

Marc Voogt (BSc) – Operational benefits since the connection of Amsterdam Airport Schiphol with the Network Manager.

Key to enabling growth at Schiphol without compromising on safety, efficiency and the environment is to increase the predictability of traffic flows. Procedures put in place by Collaborative Decision Making (CDM) support predictable traffic flows not only at Schiphol but also in the surrounding airspace of Central Europe…Research is carried out into the effectiveness of CDM since the data -connection and the impact on operational partners at Schiphol and in the EUROCONTROL  network. The data-connection is identified to have improved the accuracy of take-off time predictions at Schiphol considerably with an average monthly increase of 6% of all departing movements regarded as having a predictable take-off time. Towards the network this take-off time predictability has increased significantly. In relation to similar major-hub airports, the increased take-off time predictability and the exchange of more accurate operational planning data between Schiphol and the NMOC are identified to have contributed to the significantly high compliance to imposed take-off times (93% of all departing movements) supporting stable Network Management. Although significant increases in delay throughout the EUROCONTROL network are increasingly affecting a stable planning of aircraft parking stands at Schiphol, indications for a reduction in stand-delay and other KPIs related to improved flow-efficiency at the airport are identified.

Graduated: April 2019

Tessa Rietema (BSc) – Capacity requirements analysis of civil air traffic in military controlled airspace

The determination of the capacity of the Lelystad Terminal Manoeuvring Area (TMA) is complex and brings different challenges. The opening of Lelystad airport for civil air traffic is the motivation to perform research into the capacity of the Lelystad TMA…The aim of this research is to help CLSK to determine the capacity factors and the capacity of the Lelystad TMA…By means of interviews and expert sessions with operational experts of CLSK, data is created to use during the research. With the data, the volume and capacity of the TMA is calculated. After this, a bottleneck analysis is conducted for the capacity of the handling process. The bottleneck in the handling process is the airport with its aircraft stands. After this, the TMA is the limiting capacity compared with the runway. Additionally, the annual maximum flight movements of 4,000 and 10,000 is feasible with the structure of the TMA. When the airport becomes operational for commercial traffic, the established capacity must be validated

Graduated: February 2019

Bas Broekstra (BSc) – Impact of Special Events on Airspace

Large-scale (e.g. Tour de France, Nuclear Security Summit, etc) or other special events can mean a temporary  increase in (concentrated) traffic in the airspace. These interruptions of normal operations can have impact on the airspace capacity and air traffic controller workload. The objectives of the research is to analyse and evaluate the impact of past events, to provide insight in the capacity impact of an event. To do so, operational requirements of different events are evaluated and analysed, with the aim to provide possible improvements to be better prepared for future events. Improvement could include procedural recommendations to manage special events in the airspace, to ensure that capacity is managed in efficient ways in the future. How do current procedures, to determine the impact of special events on airspace capacity, justify the impact on operations to stakeholders in Dutch airspace?

Graduated: July 2018

Marc Eijkens (BSc) – Analysis of Vertical Flight Trajectory Efficiency

The objective of this research is to analyse the effects of the current hand-over conditions on both horizontal and vertical flight trajectory efficiency. This analysis provides insight into the significance of how the current hand-over conditions affect operational efficiency. It will present an understanding of the impact on air traffic controller (ATCo) workload when this additional coordination is carried out. Besides analysing the impact on operational efficiency and ATCo workload, the research will provide possible solutions to the problem at hand. Solutions could range from procedural changes to technical innovations which will not negatively impact/increase controller workload.

Graduated: July 2018

Gijs Peters (BSc) – Impact Analysis on the Airside Infrastructure at Schiphol

The airside infrastructure layout of AAS is very complicated, and bottlenecks are easily formed. With this growing amount of movements, bottlenecks will occur more often and influence the capacity. Every stakeholder has its own perspective on the current problems and cooperation is difficult to achieve. The research gives an overview of the current bottlenecks at the runways, taxiways and gate/buffer areas to create more awareness of the seriousness of the problem. More awareness will stimulate a better cooperation between the main stakeholders of AAS’ airside infrastructure. Also, a list of possible solutions is created.

Graduated: July 2018

Martijn Ringelberg (BSc) – Airline Strategies’ Impact on Gate Occupancy

How do airline characteristics, ranging from business model differences to variation in actual procedures, affect AAS airside capacity? Schiphol airport is reaching its limit based on the cap of 500.000 movements per year. For reaching this amount of movements a lot of capacity constraints have already been tackled, not all of them however. There are numerous airlines operating at Schiphol, and all of these airlines have various differences and equalities ranging from differences between business models to differences between pilots. The fleet size or structure of an airline for example can impact the maximum number of movements per hour of a runway as bigger aircraft need to have more separation than smaller aircraft. Another issue is the communication between airlines and airport. This may lead to congestion as the airport wouldn’t be able to plan the gate capacity well in advance. When the impacts of airline strategies are known in more detail, AAS and LVNL would be able to plan accordingly to have less capacity congestion.

Graduated: July 2018

Roel Wouters (BSc) – Impact of Local A-CDM on the Operational Efficiency at Mainport Schiphol

AAS is at the final stage of having Airport- collaborative decision making (A-CDM) completely implemented. The last step is to connect the network manager and then AAS will be a CDM airport. The network manager is currently not yet connected and, therefore, not taken into account in this study since there is not any data available yet. Local A-CDM is currently implemented at AAS which includes the four other main stakeholders (Airport operator, Aircraft operator, ATC and ground handlers). Local A-CDM should improve the stakeholders’ operational efficiency by improving the predictability and decision making.  It is likely that A-CDM has been beneficial for the operation of each involved stakeholder at AAS. However, for all stakeholders it is still uncertain how much the operational efficiency has improved thanks to the implementation of local A-CDM. The aim of this study is researching how local A-CDM has exactly improved the operation’s efficiency for each involved A-CDM stakeholder at Mainport Schiphol until now, and what the exact benefits are.

Graduated: July 2018

Huib de Jong (BSc) – How can Schiphol transition to use of APOC in an effective way?

ATC controllers are respected for their high-performance jobs, training is consistent and on high quality level, still the individual controller has the opportunity to guide air traffic in the most efficient way for that moment. An analysis of ATC decision making (taxiway, gates, runway usage, approach and take-off routing), finding deviations and variations in the operation, should determine the current way of working and should form the basis to work towards APOC. In APOC, a key difference between the current situation is the way of information sharing and availability, this difference with the current situation should be analyzed, providing the insight how to transition towards the use of APOC. The results must provide how the current decision-making process impacts capacity and to what extent can these deviations and variations be reduced when APOC is used. Furthermore, what are benefits and what are the requirements to transition to this future situation. In addition, also maintaining sufficient flexibility in the operations after the decisions have been made.

Graduated: March 2018

Remsey Kanis (BSc) – Analyses of deviations and variations in the ground operations due to runway changes

Schiphol has the most runways in Europe with respect to major hub airports, this does not automatically translate to the highest ATMs. During the day runway use is changed, primarily because of the noise restrictions surrounding Schiphol. An analysis of the impact on the capacity on the ground and in air, is needed to determine, how this already complex change of runways also increases the complexity in other parts of the system. Included in the analysis the effect on TATs can be determined possibly through A-CDM data, also information from the ORS (Omgevingsraad Schiphol) must be considered as input. The results must provide an effect analysis on specific parts of the system and the reasoning, the related stakeholders need to be covered also the cost and benefits in operational sense need to be addressed.

Graduated: March 2018

Joep Boekhout (BSc) – Analysis of the effectiveness of the limitation/regulations in controlling airspace towards and from Schiphol

Air traffic controllers find the most efficient way to align aircraft towards the runway, maintaining separation requirements, trying to prevent delays, choosing the most fuel-efficient routes for airlines from and to the airport. Although in some cases regulations in the airspace are deemed necessary to cope with an increase in demand, on top of that pilots (airlines) tend to defeat the system by asking for directs (deviations), instead of following the rest. In addition, relaxing some airspace constraints did not have the effect of a higher utilisation of the airspace. The analysis should provide insight in the effectiveness of limitation/regulations used in the airspace. Possible input can be an aircraft priority study (KLM), that provides the airline with information which aircraft to speed up or slow down. The results of the research must provide air traffic controller with the impact of certain regulations and also airspace users with the insight on how their decisions impact the whole system. Included should be at least a list of the most used regulations with their impact/effectiveness and deviations by users including their impact as well. The customer wants to get insight in the current effectiveness of Network Manager regulations, and in particular the effect of airline/pilot behaviour on the effectiveness of regulations.

Graduated: March 2018

Stijn Brunia (MSc) – Predicting controller workload within individual ground control sectors.

At Schiphol airport all ground traffic is handled by ground controllers, who are all working on the traffic within a specific geographical sector. There are four main sectors, but one controller can also handle multiple different sectors. This means that the number of active controller will fluctuate during the day. There is however little insight in what the workload of a specific sector will be within the nearby future. Next to this there is also little insight in how the workload of the Schiphol ground controllers effects the capacity of the taxi system as a whole. Since the taxi system capacity has a large influence on the capacity for Schiphol as a whole, more insight within the parameter of ground controller workload could be of significant use, as it can be used in deciding on what number of controller will need to be active.  This research will try to create a tool in which the upcoming workload can be estimated using the planned operational data.

Graduated: July 2023

Stijn van Selling (MSc) – Supporting Time-Based Separation and Merging in Approach Control.

Aviation as a whole is expected to grow, therefore adjustments to the current air traffic management system will need to be made. Part of these adjustments is the switch from distance-based separation to time-based separation. This will allow the airport capacity to increase when strong headwinds are present on the active runway. An increase in runway capacity will also result in less holding time required as more aircraft can land in the same amount of time, hence saving fuel and thus making for a more environment friendly operation. In order to facilitate time-based separation, the air traffic controller will need assistance in terms of decision support tools as time-based separation is not easily visualised on a 2D map. This research will thus try to design, implement and test such a decision support tool in order to support time-based separation in approach control.

Graduated: April 2023

Eneko Rodríguez (MSc) – Investigating the effects of Flexible Use of Airspace availability and plannability on fuel efficiency

All military airspace in the Amsterdam Flight Information Region (FIR) falls under the concept of Flexible Use of Airspace (FUA), which no longer considers airspace as purely ‘civil’ or ‘military’ but rather as a continuum to be allocated temporarily according to user requirements. The complexity of FUA lies in the challenge to harmonize the airspace usage according to these requirements, which largely contradict one another. On the one hand, the military user benefits from using the airspace flexibly, as the effectiveness of their missions and exercises depend on the availability of weather and equipment conditions. On the other hand, the civil users benefit from a high plannability to efficiently execute their operations. By modeling the fuel consumption of civil traffic, the effects of availability and plannability of the FUA in Amsterdam FIR can be computed. While FUA availability determines the route followed by a flight, FUA plannability determines how early the true trajectory is known. Announcing the FUA usage earlier results in avoiding to carry a surplus fuel, which increases the weight and thus fuel burnt of the aircraft. By understanding these effects, new guidelines of FUA usage and plannability may be proposed in the context of the ongoing Dutch Airspace Redesign Programme.

Graduated: August 2022

Bart Rozendaal (MSc) – A neural network approach in optimising
airport strategy with trajectory prediction

As the airspace is getting increasingly crowded worldwide, the capacity management of airports is more important than ever. To avoid unnecessary and costly delays, it is crucial for airports to have well timed strategies and reliable arrival predictions. To achieve this, airports need accurate long-term trajectory predictions such that arrival times can be estimated with high precision. Countless factors such as weather conditions, restricted fly areas and air traffic control clearances cause route uncertainties, making it difficult to predict long-term trajectories accurately. In this thesis, a bidirectional LSTM recurrent neural network is proposed to solve a sequence-to-sequence learning problem and predict the most likely route flown by the aircraft before take off. The network is trained on historical flight plans only, making it easy to implement. The data exists of incoming flights on Schiphol international airport within Europe. Different Hyperparameters are tested to improve performance of the network.

Graduated: July 2022

Thomas Vermeulen (MSc) – Evaluation and assessment of the performance of the KNMI Schiphol Kansverwachting (SKV) for Mainport Schiphol with respect to wind direction and wind gusts

Accurate weather forecasts are crucial information to regulate the operations at Schiphol Airport. Sudden changes in weather conditions need to be communicated in a fast and efficient way to maintain the safety and efficiency for flight operations. KNMI provides a probabilistic weather forecast, called the Schiphol Kansverwachting (SKV), which is produced using output of numerical weather prediction models in combination with the latest observations and several statistical post-processing tools. In particular information on the wind direction and the wind gusts is highly important to support air traffic control. Relatively large errors could lead to restrictions which were in the end not needed or it could lead to restrictions which were issued too late. This research will evaluate the performance of the SKV of wind direction and wind gusts for three different weather models: HIRLAM, HARMONIE and ECMWF. Quantitative information on the forecasting errors will be identified, but also suggestions for possible improvements on the weather forecasts will be part of the result of this study.

Graduated: July 2022

Wesley Vork (BSc) – Develop sequential steps towards a Multi Airport System (MAS)

Dutch airports have grown significantly over the years. This growth is occurring almost autonomously. No mechanisms have been put in place to strategically balance this growth between Dutch airports, routes, or airspace. Without major reforms, the maximum capacity of the airspace will soon be reached. The relationship between EHLE, EHEH, EHRD and EHAM is under scrutiny. With autonomous growth and without mitigating measures, this will lead to the first airspace bottlenecks in 2023 and contiguous bottlenecks in 2035. By examining how air traffic can be better handled through joint air traffic management, the capacity bottlenecks can be addressed. By conducting a thorough research on the MAS, it will become clear what problem the MAS solves and how this system can be used to solve the capacity bottlenecks.

Graduated: July 2022

Max Aalberse (MSc) – Optimizing the distribution of aircraft over the IAF

Around Schiphol and many other airports the amount of movements allowed is constrained due to the considerable noise pollution from aircraft. For a large part the noise pollution is created by arriving aircraft that are in between the IAF and the RWY. During this period the aircraft are in so called transition. These transition routes are usually already optimized to reduce the noise disturbance to surrounding residents, but due to the positioning of the runways this is not always possible. A different distribution of the aircraft over the IAF could result in less noise disturbance for surrounding residents, but would also increase flight times and fuel usage and therefore an increase in other emissions such as CO₂. The goal of this research is to create a parameterized model that optimally distributes the aircraft over the IAF based on a quantitative trade-off between noise disturbance and CO₂ emissions. Resulting in a model that is potentially able to reduce noise disturbance around airports while keeping the increase in environmental impact at a minimum.

Graduated: June 2022

Edzer Oosterhof (MSc) – Effect of Trajectory Prediction Uncertainty on Debunching of Inbound Air Traffic

With the current growth in air traffic and the resulting developments in terms of environmental issues and noise abatement, the pressure on the Area Control Center (ACC) is growing. On the one hand the Terminal Control Area (TMA) requires arriving traffic to be handed over accurately sequenced and merged, and on the other hand the ACC tries to minimize the miles flown in its sector. At the tactical level, there are Air Traffic Flow Management (ATFM) measures in place for traffic within Europe. However, no such tactical measures exist for traffic from the North Atlantic Tracks, increasing the probability that bunching occurs in the ACC during peak loads. By tactically predicting bunching in the sector and at the Initial Approach Fixes, a concept for debunching should be devised that focusses on airborne delay consumption and sequencing of traffic in the Upper control Areas (UTA) before it enters the Control Area (ACC), decreasing the pressure on the ACC.

Graduated: March 2022

Rebekka van der Grift (MSc) – Aircraft Noise Model Improvement by Calibration of Noise-Power-Distance Values Using Acoustic Measurements

The impact of the aircraft industry on the environment becomes more evident every day. Especially for local communities around the airport, the noise nuisance is an important factor which puts a strain on the capacity of Schiphol mainport. This capacity is based on the noise levels around airports, which are calculated with noise models based of key input parameters. The accuracy of these models is thus of great importance for the Schiphol mainport and the local communities. This research aims to develop a dynamic noise model based on real world aircraft noise measurements taken by NOMOS. The measurements will be used to calibrate certain input parameters to minimise any differences between model and measurements. This method helps to keep the model up to date and validated. Using measurements instead of standard input parameters is expected to increase the accuracy of the model, but also increase the trust of local communities in noise modelling.

Graduated: January 2022

Stephanie Wiechers (MSc) – Design and Evaluation of a Support Tool for Planning Adherence While Holding Inbound Air Traffic

As Schiphol is one of the busiest airport in the world, with tight flight schedules and urban areas that lie under arrival routes, adherence to the time planning is very important. When extreme weather conditions cause delays over the entire arriving fleet, holding stacks are installed at the three Initial Approach Fixes (IAFs) around Schiphol. In the current operational environment, little support is offered to the holding stack controller (ACC) to gain an overview of the effects of speed and wind on the turn times and difference between inbound and outbound leg velocity. With increased support, the controller will be able to make decisions based on representative information and with that, deliver inbound aircraft to Approach (APP). The (expected) resulting increased EAT adherence should lead to more orderly traffic in the TMA, improving capacity and workload.

Graduated: December 2021

Soraya van Beek (MSc) – Improving probabilities of poor visibility and ceiling

In order to optimize the current Schiphol operations, an accurate weather forecast is of great importance. The Royal Netherlands Meteorological Institute (KNMI) provides a probabilistic weather forecast for Low Visibility Procedures (LVPs) to Schiphol, which is computed using deterministic weather models. If these LVPs occur due to low visibility or low ceiling, adjusted capacity and flow restriction are needed within airport operations. Inaccurate forecasting can lead to last-minute restrictions or restrictions when not needed. This research will assess the performance of the probabilistic forecast of visibility and ceiling at Schiphol airport. This will be done for the performance of three different weather models: HIRLAM, HARMONIE and ECMWF. Causes for inaccurate forecasting will be identified and suggestions for improvement of the probabilistic weather forecast will be the end result of this research.

Graduated: October 2021

Gijs Bekkers (BSc) – Improving Operational Plan Preparation for Amsterdam Airport Schiphol

Stakeholder preparation for future operation is currently carried out mostly individually, with limited and mostly untimely access to relevant information. Through identifying and mapping plan development for each involved actor, it is possible to find commonalities and moments of information exchange. Data that could be of relevance for others is often kept private, due to lack of insight in handling by others and lack of knowledge on collective benefits of information-sharing. Using feedback from the Airport’s Operation Centre (APOC) on their Airport Operations Plan (AOP), and from LVNL on their OPS plan, together with expert recommendations, poses improvements for desired information sharing within stakeholders. Optimizing the plan-establishment processes and collectively arranging operational preparation yields benefits for all involved stakeholders. To finally ensure proper execution, data-exchange and arrangements should be constantly monitored using chosen performance indicators.

Graduated: June 2021

Janjaap Wijnker (BSc) – Evaluating the accuracy of information provided by the (D-1) OPS plan

In early 2020 LVNL implemented the OPS plan with the objective to improve the alignment of traffic demand with available capacity. This can be achieved by improving the predictability of the operations and make this transparent and accessible for the stake-holders. Every day the PRE-TACT unit develops an OPS plan for the following operational day. The plan contains two types of information, external factors that might impact the capacity, and recommendations for the most optimal operations. The recommendations are based on the external factors, for example the predicted traffic demand and weather forecast. These two factors contribute to the configuration of runways, and the runway selection determines the required capacity. In order to for LVNL to improve possible deficiencies of the OPS plan, the aim of this research study is to evaluate the accuracy and precision of the predicted traffic demand. The analysis focusses on the difference between predicted and actual traffic demand on a 20 minute resolution. In addition, the implications of factors contributing to the proposed runway configuration will be assessed since the use of different runways could have a significant impact on the capacity.

Graduated: June 2021

Christophe Vakaet (MSc) – Taxi Time Prediction with Classical and Auto Machine Learning at Schiphol Airport

Ground control uses the Departure Sequence Planner (DSP) to optimally plan departures within the operational constraints. The DSP uses an estimated Variable Taxi Time (VTT) to calculate an aircraft’s Target Take-Off Time (TTOT). If the VTT is underestimated flights will not make the determined TTOT, while an overestimation requires the air traffic controller to tactically hold an aircraft. These consequences result in delays, capacity losses, additional workload, and uncertainty. This uncertainty inhibits further operational optimizations. The VTT is currently predicted based on the average taxi times for different gate-runway combinations, wake turbulence categories, deicing procedure, and simplified runway configuration. The goal of this project is to improve VTT predictions by employing machine learning techniques and additional data sources such as traffic density, weather, aircraft type, and more.

Graduated: June 2021

Mathijs Post (MSc) – Air Traffic Flow Management for Amsterdam Airport Schiphol

Air Traffic Flow Management is a measure to optimize the flow of traffic in the European air transportation system. Flights are planned such that these can be operated with as little delay as possible. However, on the day of operation many changes can still happen. Amsterdam Airport Schiphol is the biggest contributor to Airport ATFM Delay in Europe, meaning many flights are delayed because of congestion or other airport related reasons at Schiphol. Besides Airport ATFM Delay, the arrival punctuality of flights at Schiphol can be improved. More insights into the causes and interactions of operational parameters is necessary to understand the main contributors for Airport ATFM Delay and arrival delay. A Bayesian Network is proposed, which is a Probabilistic Graph Model that can find interactions between variables and can identify the operational conditions leading to Airport ATFM Delay and arrival delay.

Graduated: June 2021

Bart Bouwels (MSc) – Air Traffic Management Concept for Off-Idle Continuous Descent Operations at Schiphol

Due to the continued growth of the aviation industry, emission and noise production are at an all-time high. In order to reduce this, conventional approaches could be replaced by continuous descent approaches (CDA). These eliminate all level segments, greatly reducing the average thrust setting, resulting in large reductions in noise and emission production. The problem with almost all CDA procedures is that it makes it much more difficult to predict the future position of an aircraft since it flies its own optimal descent profile, with zero thrust. This results in a need for more separation, greatly reducing the airport capacity. This can largely be solved by using a fixed, constant descent angle for all aircraft. Assessing the robustness of such a concept for a high capacity airport is therefore an important stepping stone towards actual implementation.

Graduated: May 2021

Brian Verhoeven (MSc) – Improving the predictability of Aircraft Induced Lightning (AIL) for Mainport Schiphol

Lightning strikes to aircraft are not uncommon in aviation. Although they are not dangerous anymore, they can still result in damages to the aircraft and delay airline operations. Passengers can get scared from the lightning strike as well. Especially in the region around Amsterdam Schiphol Airport, AIL can occur during fall and winter as well. Estimations are that 90% of the lightning strikes are a result of the aircraft triggering a lightning strike, rather than being accidentally struck. In order to prevent as many strikes as possible, it is thus key to understand this process. Therefore, this research aimed to gain a as complete as possible understanding of the process of AIL and use this knowledge to supply new information about AIL to pilots, as AIL is not included in most standard pilot trainings. This can allow pilots to become more aware of AIL and prevent more lightning strikes and the corresponding inconveniences from occuring.

Finished internship: January 2021

Jeanette Derks (MSc) – Coordinated Arrival and Departure Management for Dependent Runway Operations

The foreseen increase in air traffic movements in combination with eased separation minima between aircraft, redefined by the International Civil Aviation Organization (ICAO) in 2015, is expected to emphasize current runway dependencies at airports even further. As the number of aircraft in vicinity of an airport will increase, conflicting flight paths between arriving aircraft and departing aircraft will become a bigger safety hazard and will affect the efficiency of both the arrival and departure traffic flow. Airports that rely on dependent runways in their daily operation await serious congestion problems if no coordination between arrival and departure management will be initiated soon. Therefore, this research aimed to increase runway configuration capacity at airports that experience interference between arrival and departure capacity due to the use of dependent arrival and departure runways by developing and exploring multiple concepts for a coordination mechanism between Arrival and Departure Management.

Graduated: November 2020

Robin Vervaat (MSc) – Priority-based flight scheduling in the tactical phase

Years of growth in air travel have meant that, as usage is nearing current capacity, delays are becoming virtually inevitable for air carriers operating in our airspace. Flight delays have a significant impact on airport and airline operations, as well as their cost. As such, tactical planning of the flights has become increasingly important, especially for a hub-operator with many connecting passengers. In collaboration with LVNL, KLM and Amsterdam Airport Schiphol, a novel model is being investigated tasked with the Arrival Sequencing and Scheduling of flights considering (airline) priority criteria. Smarter use is to be made of the available infrastructure in order to increase capacity and decrease delay (costs), however, fairness and equality between stakeholders will still need to be upheld.

Graduated: September 2020

Bas Timmer (BSc) – Analysing inbound sources of information to improve the predictability and accuracy of the landing times

With the growing aviation industry in Europe, efficient use of the inbound capacity becomes even more important. One of the determining factors in capacity is the ability of accurately predict the landing time of aircraft. LVNL systems AAA and ASAP generate their inbound sequence planning based on Estimated Landing Times (ELDT) calculated from a variety of data sources. When CDM was implemented, business rules were put in place to prioritize certain data sources above another based on quality and accuracy. Nowadays, the quality and accuracy of these sources are thought to be different. Reviewing the current business rules is done by analyzing the quality and accuracy of the data sources, and how flight characteristics or procedures can influence the accuracy of the ELDT.

Graduated: August 2020

Max (MSc) – Aircraft noise model validation using noise measurement feedback

One of the current factors limiting the growth of the aviation industry in the Netherlands is the relationship between the aviation sector and local communities around airports. Aircraft noise production is one of the main causes of nuisance in residential areas reported by RIVM. It is therefore, for the aviation industry as a whole, of great importance to gain a better understanding of the methodology of aircraft noise modelling and make improvements on this modelling process if deficiencies in the current model are detected. The validation of the aircraft noise model, using noise measurements taken around the airport, is crucial for the scientific foundation of the model. This scientific foundation is expected to increase the transparency in how noise calculations are performed, which increases community trust in the aviation industry as a whole.

Graduated: July 2020

Ashley Scheenloop (BSc) – Impact of the fleet mix on the outbound capacity at Schiphol Airport

With the future growth in amount of flight movements in the aviation sector, efficient use of the airport resources are getting more and more important. In 2019 it was seen that the declared runway capacity at Schiphol airport is not reached during the outbound peaks. Previous research showed that the aircraft type (Wake turbulence category) influences the runway capacity. With the use the A-CDM principle, the outbound phase at Schiphol airport is analysed. This way the time spent, between the time references (A-CDM Milestones), for each Wake turbulence category is analysed and compared. This will provide an insight on the behaviour of these aircraft types, and indicates a possible significant difference/bottleneck. Besides the active runway combinations are analysed during these outbound peaks.

Graduated: July 2020

Marc Out (BSc) – Reducing the fluctuations on the outbound planning at Amsterdam Airport Schiphol

At Amsterdam Airport Schiphol, the outbound planning is created by the Collaborative Pre-Departure Sequence Planner (CPDSP). Currently, this outbound planning is fluctuating because of frequent updates of the Target Off-Blocks Time (TOBT). Having a dynamical outbound planning could create in a loss of valuable outbound capacity and increasing the risks in regulated flights by EUROCONTROL. To reduce the occurrence of frequent TOBT updates, different business rules have been analyzed for the auto-TOBT update mechanism. This mechanism updates the Target Off-Blocks Time automatically once the inbound flight has an assigned landing runway until the moment the aircraft is in-blocks or the Main Ground Handler updated the TOBT manually. The analyzed business rules had different characteristics related to the frequency of TOBT updates and the accuracy of this target time. Those two main characteristics were required to analyze to be able to have an overview which business rule creates less updates but having the same quality as in the current situation.

Graduated: July 2020

Thijs Scheffers (BSc) – Improving the outbound planning process at Amsterdam Airport Schiphol

To improve the outbound planning process of Schiphol Airport, the frequency, availability and accuracy of Estimated Landing Time (ELDT) data has been investigated. Special attention is placed on the information sharing and the calculation of the ELDT, that is calculated by Amsterdam Advanced Air traffic control system (AAA). In addition, the search for new and accurate data sources to estimate the landing time is a continuous effort. As of November, 2018, a new arrival management (AMAN) system is in use at LVNL, called Advanced Schiphol Arrival Planner (ASAP), which replaces the old arrival system, called Inbound Planning (IBP). The new AMAN has implemented different internal characteristics and processes, such as a new trajectory predictor and planning algorithm. Therefore, the new AMAN could potentially provide more accurate arrival time predictions. Both systems are compared to identify their performance.

Graduated: April 2020

Matthijs Ottenhoff (MSc) – Wind and Trajectory Uncertainty in a 4D Trajectory Management Interface

With air traffic numbers increasing, a shift in the Air Traffic Management system towards 4D flight plans, where an aircraft trajectory is pre-planned in both time and space, is foreseen. When these pre-planned trajectories are subsequently executed, unforeseen airspace perturbations, such as weather, sequencing and changing airspace constraints, will inevitably require small changes in the trajectories to be made by the air traffic controller. This perturbation management control task will consist of ensuring a safe airspace while adhering to the strict time constraints imposed by the 4D flight plan. In collaboration with LVNL, a decision support interface was designed and evaluated with the aim of visualizing possible conflict resolutions in the 4D domain. A special focus was put on the integration of wind and trajectory uncertainty information into the interface.

Graduated: March 2020

Eline Bakker (MSc) – Design and Evaluation of a Visual Interface for an En-Route Air Traffic Control Merging Task

In the past decades, the air traffic growth has resulted in increasingly complex situations involving more aircraft simultaneously. In order to guarantee safety is maintained within the increasingly crowded airspace, new solutions are expected. In collaboration with the LVNL, an Inbound Traffic Support System interface was developed. The goal of the interface is to visualize the possible solutions of an area controller’s task of merging aircraft towards a restricted waypoint in the current work domain, such that the impact of decisions made can be foreseen.  By showing the affordances of the work domain, the display keeps the air traffic controller as the active decision maker rather than issuing advisories.

Graduated: October 2019 

Femke Mollema (BSc) – Creating more capacity at Amsterdam Airport Schiphol by reducing planning inefficiencies amongst KLM, LVNL and AAS

As of today, the aviation parties at Amsterdam Airport Schiphol are connected to the European network managed by Eurocontrol NMOC (Network Manager Operation Centre) through its local Airport CDM (Collaborative Decision Making) process. Within the Dutch aviation industry, many stakeholders are involved in the air traffic process, of which three of the main stakeholders are KLM, AAS and the LVNL. Each stakeholder can influence a certain part of the air traffic process, for which they create their own planning. Other parts of the air traffic process, over which a stakeholder has no control, are influenced, and planned on, by the remaining stakeholders. Since the air traffic process is a continuous cycle all stakeholders involved carry dependencies on one another, which also influences the planning each stakeholder makes. To succeed both the overall air traffic process and thus the stakeholders’ individual process, a collaboration among stakeholders is required. The goal of this research is to determine which planning inefficiencies may arise as a result of the different points of interests of the stakeholders within the Dutch aviation sector. By determining these inefficiencies, it can be researched how these can be eliminated, which could eventually benefit the capacity problem. For the purpose of this research the focus will primarily be on KLM flights.

Graduated: August 2019

Sybren Kuiper (BSc) – Evaluation of plan stability deviations in the flow at Schiphol airport

Over the last years Schiphol has experienced a growth in aircraft movements and exchange of narrow body aircraft for wide body aircraft. The infrastructure has been unable to change at the same pace increasing the pressure on the ground operations capacity and forcing the growth into the off-peaks moments where free infrastructural capacity was available. By growing in the off peaks a new challenge arose. The unused capacity was of essential value in the system plan stability. It offered flexibility that could be used to recuperate from planning deviations. The situation created, can cause a deviation from the plan to trigger a domino through the day that cannot be halted because there is no recuperation space. To stop this effect, it is essential to perform research into the current situation of the plan stability, and the exact causes that start or continue the domino effect. To do this the research will answer the following research question: “What are the opportunities for Amsterdam Airport Schiphol and the other KDC stakeholders to improve the airside ground operational plan stability of the airport?”

Graduated: August 2019

Kyara Metz (BSc) – Evaluation of peak hour capacity at Schiphol and similar airports to determine common capacity management practices

According to EUROCONTROL, Schiphol has the most significant contribution on global ATFM airport delays of all the European Airports; weather and airport capacity were targeted as primary cause of delays. Therefore, this research investigates the potential uses of holding buffers of inbound flows at Amsterdam Schiphol Airport (AAS) during peak hour of operations to absorb delays; special attention is placed on analysing the current methods employed by Schiphol and other Airports uses holding buffer not as a reactive resource for ATCs but a everyday use tool to maximize throughput on runway.

Both quantitative and qualitative research has been used to investigate which operational possibilities LVNL has to buffer inbound traffic in the Dutch airspace and to what extent these buffers can be used in managing the operational inbound peak capacity. To determine the current linear buffer capacity, 20,000 flights from July 2018 were analysed.

Graduated: August 2019

Davey Hooijmeijer (MSc) – Schiphol noise analysis for fixed arrival routings 

In this thesis research, dutch aircraft noise model (NRM) calculations are compared to measurements to analyse the aircraft classification used in the model. To do so, a new implementation of the model has been set up to calculate with LVNL trackdata and NOMOS measurement data. First, the classification approach is analysed as prescribed, which shows clustering of aircraft types when compared to measurements. After, the theoretical input data as prescribed for the model is assessed and replaced by real data for each type specific. This leads to improvements of the model calculations when compared to measurements and shows that aircraft-specific flight-information would improve the model significantly. Concluding, it is shown that aircraft noise models strongly rely on the quality of the input data. Current input data shows certain mismatches with respect to reality, resulting in differences between calculations and measurements. However, the calculations can give valuable insights in the effect of operations on the overall noise exposure.

Graduated: July 2019

Anouk Hollebeek (BSc) – Evaluation of AMAN implementation to establish improvements in the arrival efficiency

A new Arrival Management system, called Advanced Schiphol Arrival Planner (ASAP), was implemented in 2018 to regulate the arrival traffic flows at Amsterdam Schiphol Airport (AAS). ASAP aims to be an assisting support tool for the Approach Planner (APLN)  to monitor and safety merge inbound traffic flows in the Dutch Terminal Control Area (TMA). To validate the implementation of ASAP diverse analysis have been run. This work describes some recent insights and findings regarding the performance and interaction between users (ATCs) and ASAP. Particular attention is placed to establish the moment and type of interaction between the different users. The performance of the tool was evaluated using four main performance indicators; Expected Approach Time (EAT) adherence, slot adherence, holding ratio, influence of APLN.

Graduated: July 2019

Flore Wassenberg (BSc) – D-1 process impact evaluation

In 2018, it was started as part of the development of the capacity management function was the D-1 project. The D-1 project intends to provide an operational and capacity plan before the day of operation. Within the D-1 project team there is a need to validate the quality of the predicted traffic demand, because the prediction generated was not quantitatively evaluated afterward. To explore the reliability and usability of the traffic demand prediction at D-1, a bachelor thesis research has been performed. This research has been done by means of comparing the D-1 traffic demand prediction with the demand on the day of operation. The last submitted flight plans at D0 have been compared to the data predicted on D-1. The sample used contains data that was generated during a period of three months of the D-1 project trial. The research concludes that the traffic demand prediction is for parts not accurate enough to support the D-1 decision making process.

Graduated: July 2019

Casper Moll (BSc) – Capacity analysis of airport slot planning and air traffic demand

According to Eurocontrol,  in 2017 Schiphol Airport was the airport with the biggest inbound ATFM delay of all major airports in Europe. One of the reasons that could cause the inbound ATFM delay is the so called ‘bunching’ effect at the border of the Dutch airspace. The objective of this research is to determine if the encountered planned bunches at -3-hour planning phase has an impact on the airport slot planning. This research focusses on the airport slot declaration and the planned demand based on the last filed flight plans, covering a period from the 25th of October 2017 till the 27th of October 2018. The analysis  contains 254,000 arriving flights in both winter and summer season. The analysis determines to which extent the bunching occurs in the airport slot declaration, and at the border of the Dutch airspace. The results reveal that bunching are present in the pre-planning phase within the airport slot declaration and is caused by the skewness within the airport slot-brackets. The analyses render similar patterns in which overdemand occurs within the time-brackets. The subsequent relationship between the airport slot planning and air traffic demand is around 48%, within the assumptions and limitations of the research. This means that 48% of the flights which are planned in a period with overdemand within the airport slot allocation, also tend to arrive in a period with overdemand at the border of the the Dutch airspace.

Graduated: June 2019

Marc Riebeek (BSc) – Comparison of airport slots and schedule & flight planning

Amsterdam Airport Schiphol is the airport with the most airport Air Traffic Flow Management (ATFM) delay in Europe in 2017. One of the causes of the ATFM delay is that airlines do not adhere to their allocated airport slots. With providing insights into deviation between flight schedules or flight plan and airport slot, causes of deviating to the airport slot are identified. This research is done by means of analysing the deviations to identify the characteristics of the deviations. In addition, interviews with airlines and a ground handler and literature about possible causes are used to provide insights. The main findings are that ~ 3.3% of the flight schedules deviate from the airport slot. The deviation between flight plan and airport slot is around 67% of arriving flights. This deviation of flight plans means that the estimated in block time (EIBT), deviates more than 5 minutes from the airport slot. Both in absolute amount and relative percentage, general aviation and cargo airlines are the business models that cause the most deviation between flight schedule and airport slot. An agreement between the general aviation ground handlers and the typical business of cargo are the main reasons for the deviation. The full-service carriers and low-cost carriers cause in absolute number, the most deviation between the EIBT based on flight plan and airport slots. If the EIBT, based on the flight plan, is earlier than the airport slot, more than 90% of these arrivals are planned earlier because of schedule buffers.

Graduated: June 2019

Mats Dirkzwager (MSc) – Design and Evaluation of a Visual Interface for Separation Support in Time-Based Approach Air Traffic Control

On final approach, an Approach (APP) Air Traffic Controller (ATCo) is responsible for keeping sufficient separation between aircraft lining up on the ILS. The current industry standard is to separate these aircraft with a minimum distance, called Distance-Based Separation or DBS. European regulation requires all European airports to implement separation based on time (TBS) before 2024. Due to this implementation, effectively changing the APP ATC task from a geometrical to a time-based problem, and because of further complications such as the European Re-categorisation of aircraft types, experts fear that the theoretical gains attainable by using TBS will not be fully realised. In this research, a display tool concept to aid APP ATCos in realising the full potential of TBS, the Ideal Turn-In Point (ITIP) display is designed and evaluated with respect to the current state of the art. The ITIP display assists controllers in selecting optimal approach strategies starting from the moment aircraft enter the Terminal Control Area. The display aims to assist the operator by showing the possibilities and restrictions in the system rather than giving (restricting) advisories. In an initial proof-of-concept experiment, comparing the ITIP display to the current industry state of the art display, promising results were found; the ITIP display was shown to maintain safety and increase efficiency, whilst maintaining controller workload. The current industry state of the art display is a tool designed by the National Air Traffic Services, currently operational at London Heathrow Airport.

Graduated: June 2019

Marc Voogt (BSc) – Operational benefits since the connection of Amsterdam Airport Schiphol with the Network Manager.

Key to enabling growth at Schiphol without compromising on safety, efficiency and the environment is to increase the predictability of traffic flows. Procedures put in place by Collaborative Decision Making (CDM) support predictable traffic flows not only at Schiphol but also in the surrounding airspace of Central Europe…Research is carried out into the effectiveness of CDM since the data -connection and the impact on operational partners at Schiphol and in the EUROCONTROL  network. The data-connection is identified to have improved the accuracy of take-off time predictions at Schiphol considerably with an average monthly increase of 6% of all departing movements regarded as having a predictable take-off time. Towards the network this take-off time predictability has increased significantly. In relation to similar major-hub airports, the increased take-off time predictability and the exchange of more accurate operational planning data between Schiphol and the NMOC are identified to have contributed to the significantly high compliance to imposed take-off times (93% of all departing movements) supporting stable Network Management. Although significant increases in delay throughout the EUROCONTROL network are increasingly affecting a stable planning of aircraft parking stands at Schiphol, indications for a reduction in stand-delay and other KPIs related to improved flow-efficiency at the airport are identified.

Graduated: April 2019

Tessa Rietema (BSc) – Capacity requirements analysis of civil air traffic in military controlled airspace

The determination of the capacity of the Lelystad Terminal Manoeuvring Area (TMA) is complex and brings different challenges. The opening of Lelystad airport for civil air traffic is the motivation to perform research into the capacity of the Lelystad TMA…The aim of this research is to help CLSK to determine the capacity factors and the capacity of the Lelystad TMA…By means of interviews and expert sessions with operational experts of CLSK, data is created to use during the research. With the data, the volume and capacity of the TMA is calculated. After this, a bottleneck analysis is conducted for the capacity of the handling process. The bottleneck in the handling process is the airport with its aircraft stands. After this, the TMA is the limiting capacity compared with the runway. Additionally, the annual maximum flight movements of 4,000 and 10,000 is feasible with the structure of the TMA. When the airport becomes operational for commercial traffic, the established capacity must be validated

Graduated: February 2019

Bas Broekstra (BSc) – Impact of Special Events on Airspace

Large-scale (e.g. Tour de France, Nuclear Security Summit, etc) or other special events can mean a temporary  increase in (concentrated) traffic in the airspace. These interruptions of normal operations can have impact on the airspace capacity and air traffic controller workload. The objectives of the research is to analyse and evaluate the impact of past events, to provide insight in the capacity impact of an event. To do so, operational requirements of different events are evaluated and analysed, with the aim to provide possible improvements to be better prepared for future events. Improvement could include procedural recommendations to manage special events in the airspace, to ensure that capacity is managed in efficient ways in the future. How do current procedures, to determine the impact of special events on airspace capacity, justify the impact on operations to stakeholders in Dutch airspace?

Graduated: July 2018

Marc Eijkens (BSc) – Analysis of Vertical Flight Trajectory Efficiency

The objective of this research is to analyse the effects of the current hand-over conditions on both horizontal and vertical flight trajectory efficiency. This analysis provides insight into the significance of how the current hand-over conditions affect operational efficiency. It will present an understanding of the impact on air traffic controller (ATCo) workload when this additional coordination is carried out. Besides analysing the impact on operational efficiency and ATCo workload, the research will provide possible solutions to the problem at hand. Solutions could range from procedural changes to technical innovations which will not negatively impact/increase controller workload.

Graduated: July 2018

Gijs Peters (BSc) – Impact Analysis on the Airside Infrastructure at Schiphol

The airside infrastructure layout of AAS is very complicated, and bottlenecks are easily formed. With this growing amount of movements, bottlenecks will occur more often and influence the capacity. Every stakeholder has its own perspective on the current problems and cooperation is difficult to achieve. The research gives an overview of the current bottlenecks at the runways, taxiways and gate/buffer areas to create more awareness of the seriousness of the problem. More awareness will stimulate a better cooperation between the main stakeholders of AAS’ airside infrastructure. Also, a list of possible solutions is created.

Graduated: July 2018

Martijn Ringelberg (BSc) – Airline Strategies’ Impact on Gate Occupancy

How do airline characteristics, ranging from business model differences to variation in actual procedures, affect AAS airside capacity? Schiphol airport is reaching its limit based on the cap of 500.000 movements per year. For reaching this amount of movements a lot of capacity constraints have already been tackled, not all of them however. There are numerous airlines operating at Schiphol, and all of these airlines have various differences and equalities ranging from differences between business models to differences between pilots. The fleet size or structure of an airline for example can impact the maximum number of movements per hour of a runway as bigger aircraft need to have more separation than smaller aircraft. Another issue is the communication between airlines and airport. This may lead to congestion as the airport wouldn’t be able to plan the gate capacity well in advance. When the impacts of airline strategies are known in more detail, AAS and LVNL would be able to plan accordingly to have less capacity congestion.

Graduated: July 2018

Roel Wouters (BSc) – Impact of Local A-CDM on the Operational Efficiency at Mainport Schiphol

AAS is at the final stage of having Airport- collaborative decision making (A-CDM) completely implemented. The last step is to connect the network manager and then AAS will be a CDM airport. The network manager is currently not yet connected and, therefore, not taken into account in this study since there is not any data available yet. Local A-CDM is currently implemented at AAS which includes the four other main stakeholders (Airport operator, Aircraft operator, ATC and ground handlers). Local A-CDM should improve the stakeholders’ operational efficiency by improving the predictability and decision making.  It is likely that A-CDM has been beneficial for the operation of each involved stakeholder at AAS. However, for all stakeholders it is still uncertain how much the operational efficiency has improved thanks to the implementation of local A-CDM. The aim of this study is researching how local A-CDM has exactly improved the operation’s efficiency for each involved A-CDM stakeholder at Mainport Schiphol until now, and what the exact benefits are.

Graduated: July 2018

Huib de Jong (BSc) – How can Schiphol transition to use of APOC in an effective way?

ATC controllers are respected for their high-performance jobs, training is consistent and on high quality level, still the individual controller has the opportunity to guide air traffic in the most efficient way for that moment. An analysis of ATC decision making (taxiway, gates, runway usage, approach and take-off routing), finding deviations and variations in the operation, should determine the current way of working and should form the basis to work towards APOC. In APOC, a key difference between the current situation is the way of information sharing and availability, this difference with the current situation should be analyzed, providing the insight how to transition towards the use of APOC. The results must provide how the current decision-making process impacts capacity and to what extent can these deviations and variations be reduced when APOC is used. Furthermore, what are benefits and what are the requirements to transition to this future situation. In addition, also maintaining sufficient flexibility in the operations after the decisions have been made.

Graduated: March 2018

Remsey Kanis (BSc) – Analyses of deviations and variations in the ground operations due to runway changes

Schiphol has the most runways in Europe with respect to major hub airports, this does not automatically translate to the highest ATMs. During the day runway use is changed, primarily because of the noise restrictions surrounding Schiphol. An analysis of the impact on the capacity on the ground and in air, is needed to determine, how this already complex change of runways also increases the complexity in other parts of the system. Included in the analysis the effect on TATs can be determined possibly through A-CDM data, also information from the ORS (Omgevingsraad Schiphol) must be considered as input. The results must provide an effect analysis on specific parts of the system and the reasoning, the related stakeholders need to be covered also the cost and benefits in operational sense need to be addressed.

Graduated: March 2018

Joep Boekhout (BSc) – Analysis of the effectiveness of the limitation/regulations in controlling airspace towards and from Schiphol

Air traffic controllers find the most efficient way to align aircraft towards the runway, maintaining separation requirements, trying to prevent delays, choosing the most fuel-efficient routes for airlines from and to the airport. Although in some cases regulations in the airspace are deemed necessary to cope with an increase in demand, on top of that pilots (airlines) tend to defeat the system by asking for directs (deviations), instead of following the rest. In addition, relaxing some airspace constraints did not have the effect of a higher utilisation of the airspace. The analysis should provide insight in the effectiveness of limitation/regulations used in the airspace. Possible input can be an aircraft priority study (KLM), that provides the airline with information which aircraft to speed up or slow down. The results of the research must provide air traffic controller with the impact of certain regulations and also airspace users with the insight on how their decisions impact the whole system. Included should be at least a list of the most used regulations with their impact/effectiveness and deviations by users including their impact as well. The customer wants to get insight in the current effectiveness of Network Manager regulations, and in particular the effect of airline/pilot behaviour on the effectiveness of regulations.

Graduated: March 2018

Stijn van Selling (MSc) – Supporting Time-Based Separation and Merging in Approach Control.

Aviation as a whole is expected to grow, therefore adjustments to the current air traffic management system will need to be made. Part of these adjustments is the switch from distance-based separation to time-based separation. This will allow the airport capacity to increase when strong headwinds are present on the active runway. An increase in runway capacity will also result in less holding time required as more aircraft can land in the same amount of time, hence saving fuel and thus making for a more environment friendly operation. In order to facilitate time-based separation, the air traffic controller will need assistance in terms of decision support tools as time-based separation is not easily visualised on a 2D map. This research will thus try to design, implement and test such a decision support tool in order to support time-based separation in approach control.

Graduated: April 2023

Eneko Rodríguez (MSc) – Investigating the effects of Flexible Use of Airspace availability and plannability on fuel efficiency

All military airspace in the Amsterdam Flight Information Region (FIR) falls under the concept of Flexible Use of Airspace (FUA), which no longer considers airspace as purely ‘civil’ or ‘military’ but rather as a continuum to be allocated temporarily according to user requirements. The complexity of FUA lies in the challenge to harmonize the airspace usage according to these requirements, which largely contradict one another. On the one hand, the military user benefits from using the airspace flexibly, as the effectiveness of their missions and exercises depend on the availability of weather and equipment conditions. On the other hand, the civil users benefit from a high plannability to efficiently execute their operations. By modeling the fuel consumption of civil traffic, the effects of availability and plannability of the FUA in Amsterdam FIR can be computed. While FUA availability determines the route followed by a flight, FUA plannability determines how early the true trajectory is known. Announcing the FUA usage earlier results in avoiding to carry a surplus fuel, which increases the weight and thus fuel burnt of the aircraft. By understanding these effects, new guidelines of FUA usage and plannability may be proposed in the context of the ongoing Dutch Airspace Redesign Programme.

Graduated: August 2022

Bart Rozendaal (MSc) – A neural network approach in optimising
airport strategy with trajectory prediction

As the airspace is getting increasingly crowded worldwide, the capacity management of airports is more important than ever. To avoid unnecessary and costly delays, it is crucial for airports to have well timed strategies and reliable arrival predictions. To achieve this, airports need accurate long-term trajectory predictions such that arrival times can be estimated with high precision. Countless factors such as weather conditions, restricted fly areas and air traffic control clearances cause route uncertainties, making it difficult to predict long-term trajectories accurately. In this thesis, a bidirectional LSTM recurrent neural network is proposed to solve a sequence-to-sequence learning problem and predict the most likely route flown by the aircraft before take off. The network is trained on historical flight plans only, making it easy to implement. The data exists of incoming flights on Schiphol international airport within Europe. Different Hyperparameters are tested to improve performance of the network.

Graduated: July 2022

Thomas Vermeulen (MSc) – Evaluation and assessment of the performance of the KNMI Schiphol Kansverwachting (SKV) for Mainport Schiphol with respect to wind direction and wind gusts

Accurate weather forecasts are crucial information to regulate the operations at Schiphol Airport. Sudden changes in weather conditions need to be communicated in a fast and efficient way to maintain the safety and efficiency for flight operations. KNMI provides a probabilistic weather forecast, called the Schiphol Kansverwachting (SKV), which is produced using output of numerical weather prediction models in combination with the latest observations and several statistical post-processing tools. In particular information on the wind direction and the wind gusts is highly important to support air traffic control. Relatively large errors could lead to restrictions which were in the end not needed or it could lead to restrictions which were issued too late. This research will evaluate the performance of the SKV of wind direction and wind gusts for three different weather models: HIRLAM, HARMONIE and ECMWF. Quantitative information on the forecasting errors will be identified, but also suggestions for possible improvements on the weather forecasts will be part of the result of this study.

Graduated: July 2022

Wesley Vork (BSc) – Develop sequential steps towards a Multi Airport System (MAS)

Dutch airports have grown significantly over the years. This growth is occurring almost autonomously. No mechanisms have been put in place to strategically balance this growth between Dutch airports, routes, or airspace. Without major reforms, the maximum capacity of the airspace will soon be reached. The relationship between EHLE, EHEH, EHRD and EHAM is under scrutiny. With autonomous growth and without mitigating measures, this will lead to the first airspace bottlenecks in 2023 and contiguous bottlenecks in 2035. By examining how air traffic can be better handled through joint air traffic management, the capacity bottlenecks can be addressed. By conducting a thorough research on the MAS, it will become clear what problem the MAS solves and how this system can be used to solve the capacity bottlenecks.

Graduated: July 2022

Max Aalberse (MSc) – Optimizing the distribution of aircraft over the IAF

Around Schiphol and many other airports the amount of movements allowed is constrained due to the considerable noise pollution from aircraft. For a large part the noise pollution is created by arriving aircraft that are in between the IAF and the RWY. During this period the aircraft are in so called transition. These transition routes are usually already optimized to reduce the noise disturbance to surrounding residents, but due to the positioning of the runways this is not always possible. A different distribution of the aircraft over the IAF could result in less noise disturbance for surrounding residents, but would also increase flight times and fuel usage and therefore an increase in other emissions such as CO₂. The goal of this research is to create a parameterized model that optimally distributes the aircraft over the IAF based on a quantitative trade-off between noise disturbance and CO₂ emissions. Resulting in a model that is potentially able to reduce noise disturbance around airports while keeping the increase in environmental impact at a minimum.

Graduated: June 2022

Edzer Oosterhof (MSc) – Effect of Trajectory Prediction Uncertainty on Debunching of Inbound Air Traffic

With the current growth in air traffic and the resulting developments in terms of environmental issues and noise abatement, the pressure on the Area Control Center (ACC) is growing. On the one hand the Terminal Control Area (TMA) requires arriving traffic to be handed over accurately sequenced and merged, and on the other hand the ACC tries to minimize the miles flown in its sector. At the tactical level, there are Air Traffic Flow Management (ATFM) measures in place for traffic within Europe. However, no such tactical measures exist for traffic from the North Atlantic Tracks, increasing the probability that bunching occurs in the ACC during peak loads. By tactically predicting bunching in the sector and at the Initial Approach Fixes, a concept for debunching should be devised that focusses on airborne delay consumption and sequencing of traffic in the Upper control Areas (UTA) before it enters the Control Area (ACC), decreasing the pressure on the ACC.

Graduated: March 2022

Rebekka van der Grift (MSc) – Aircraft Noise Model Improvement by Calibration of Noise-Power-Distance Values Using Acoustic Measurements

The impact of the aircraft industry on the environment becomes more evident every day. Especially for local communities around the airport, the noise nuisance is an important factor which puts a strain on the capacity of Schiphol mainport. This capacity is based on the noise levels around airports, which are calculated with noise models based of key input parameters. The accuracy of these models is thus of great importance for the Schiphol mainport and the local communities. This research aims to develop a dynamic noise model based on real world aircraft noise measurements taken by NOMOS. The measurements will be used to calibrate certain input parameters to minimise any differences between model and measurements. This method helps to keep the model up to date and validated. Using measurements instead of standard input parameters is expected to increase the accuracy of the model, but also increase the trust of local communities in noise modelling.

Graduated: January 2022

Stephanie Wiechers (MSc) – Design and Evaluation of a Support Tool for Planning Adherence While Holding Inbound Air Traffic

As Schiphol is one of the busiest airport in the world, with tight flight schedules and urban areas that lie under arrival routes, adherence to the time planning is very important. When extreme weather conditions cause delays over the entire arriving fleet, holding stacks are installed at the three Initial Approach Fixes (IAFs) around Schiphol. In the current operational environment, little support is offered to the holding stack controller (ACC) to gain an overview of the effects of speed and wind on the turn times and difference between inbound and outbound leg velocity. With increased support, the controller will be able to make decisions based on representative information and with that, deliver inbound aircraft to Approach (APP). The (expected) resulting increased EAT adherence should lead to more orderly traffic in the TMA, improving capacity and workload.

Graduated: December 2021

Soraya van Beek (MSc) – Improving probabilities of poor visibility and ceiling

In order to optimize the current Schiphol operations, an accurate weather forecast is of great importance. The Royal Netherlands Meteorological Institute (KNMI) provides a probabilistic weather forecast for Low Visibility Procedures (LVPs) to Schiphol, which is computed using deterministic weather models. If these LVPs occur due to low visibility or low ceiling, adjusted capacity and flow restriction are needed within airport operations. Inaccurate forecasting can lead to last-minute restrictions or restrictions when not needed. This research will assess the performance of the probabilistic forecast of visibility and ceiling at Schiphol airport. This will be done for the performance of three different weather models: HIRLAM, HARMONIE and ECMWF. Causes for inaccurate forecasting will be identified and suggestions for improvement of the probabilistic weather forecast will be the end result of this research.

Graduated: October 2021

Gijs Bekkers (BSc) – Improving Operational Plan Preparation for Amsterdam Airport Schiphol

Stakeholder preparation for future operation is currently carried out mostly individually, with limited and mostly untimely access to relevant information. Through identifying and mapping plan development for each involved actor, it is possible to find commonalities and moments of information exchange. Data that could be of relevance for others is often kept private, due to lack of insight in handling by others and lack of knowledge on collective benefits of information-sharing. Using feedback from the Airport’s Operation Centre (APOC) on their Airport Operations Plan (AOP), and from LVNL on their OPS plan, together with expert recommendations, poses improvements for desired information sharing within stakeholders. Optimizing the plan-establishment processes and collectively arranging operational preparation yields benefits for all involved stakeholders. To finally ensure proper execution, data-exchange and arrangements should be constantly monitored using chosen performance indicators.

Graduated: June 2021

Janjaap Wijnker (BSc) – Evaluating the accuracy of information provided by the (D-1) OPS plan

In early 2020 LVNL implemented the OPS plan with the objective to improve the alignment of traffic demand with available capacity. This can be achieved by improving the predictability of the operations and make this transparent and accessible for the stake-holders. Every day the PRE-TACT unit develops an OPS plan for the following operational day. The plan contains two types of information, external factors that might impact the capacity, and recommendations for the most optimal operations. The recommendations are based on the external factors, for example the predicted traffic demand and weather forecast. These two factors contribute to the configuration of runways, and the runway selection determines the required capacity. In order to for LVNL to improve possible deficiencies of the OPS plan, the aim of this research study is to evaluate the accuracy and precision of the predicted traffic demand. The analysis focusses on the difference between predicted and actual traffic demand on a 20 minute resolution. In addition, the implications of factors contributing to the proposed runway configuration will be assessed since the use of different runways could have a significant impact on the capacity.

Graduated: June 2021

Christophe Vakaet (MSc) – Taxi Time Prediction with Classical and Auto Machine Learning at Schiphol Airport

Ground control uses the Departure Sequence Planner (DSP) to optimally plan departures within the operational constraints. The DSP uses an estimated Variable Taxi Time (VTT) to calculate an aircraft’s Target Take-Off Time (TTOT). If the VTT is underestimated flights will not make the determined TTOT, while an overestimation requires the air traffic controller to tactically hold an aircraft. These consequences result in delays, capacity losses, additional workload, and uncertainty. This uncertainty inhibits further operational optimizations. The VTT is currently predicted based on the average taxi times for different gate-runway combinations, wake turbulence categories, deicing procedure, and simplified runway configuration. The goal of this project is to improve VTT predictions by employing machine learning techniques and additional data sources such as traffic density, weather, aircraft type, and more.

Graduated: June 2021

Mathijs Post (MSc) – Air Traffic Flow Management for Amsterdam Airport Schiphol

Air Traffic Flow Management is a measure to optimize the flow of traffic in the European air transportation system. Flights are planned such that these can be operated with as little delay as possible. However, on the day of operation many changes can still happen. Amsterdam Airport Schiphol is the biggest contributor to Airport ATFM Delay in Europe, meaning many flights are delayed because of congestion or other airport related reasons at Schiphol. Besides Airport ATFM Delay, the arrival punctuality of flights at Schiphol can be improved. More insights into the causes and interactions of operational parameters is necessary to understand the main contributors for Airport ATFM Delay and arrival delay. A Bayesian Network is proposed, which is a Probabilistic Graph Model that can find interactions between variables and can identify the operational conditions leading to Airport ATFM Delay and arrival delay.

Graduated: June 2021

Bart Bouwels (MSc) – Air Traffic Management Concept for Off-Idle Continuous Descent Operations at Schiphol

Due to the continued growth of the aviation industry, emission and noise production are at an all-time high. In order to reduce this, conventional approaches could be replaced by continuous descent approaches (CDA). These eliminate all level segments, greatly reducing the average thrust setting, resulting in large reductions in noise and emission production. The problem with almost all CDA procedures is that it makes it much more difficult to predict the future position of an aircraft since it flies its own optimal descent profile, with zero thrust. This results in a need for more separation, greatly reducing the airport capacity. This can largely be solved by using a fixed, constant descent angle for all aircraft. Assessing the robustness of such a concept for a high capacity airport is therefore an important stepping stone towards actual implementation.

Graduated: May 2021

Brian Verhoeven (MSc) – Improving the predictability of Aircraft Induced Lightning (AIL) for Mainport Schiphol

Lightning strikes to aircraft are not uncommon in aviation. Although they are not dangerous anymore, they can still result in damages to the aircraft and delay airline operations. Passengers can get scared from the lightning strike as well. Especially in the region around Amsterdam Schiphol Airport, AIL can occur during fall and winter as well. Estimations are that 90% of the lightning strikes are a result of the aircraft triggering a lightning strike, rather than being accidentally struck. In order to prevent as many strikes as possible, it is thus key to understand this process. Therefore, this research aimed to gain a as complete as possible understanding of the process of AIL and use this knowledge to supply new information about AIL to pilots, as AIL is not included in most standard pilot trainings. This can allow pilots to become more aware of AIL and prevent more lightning strikes and the corresponding inconveniences from occuring.

Finished internship: January 2021

Jeanette Derks (MSc) – Coordinated Arrival and Departure Management for Dependent Runway Operations

The foreseen increase in air traffic movements in combination with eased separation minima between aircraft, redefined by the International Civil Aviation Organization (ICAO) in 2015, is expected to emphasize current runway dependencies at airports even further. As the number of aircraft in vicinity of an airport will increase, conflicting flight paths between arriving aircraft and departing aircraft will become a bigger safety hazard and will affect the efficiency of both the arrival and departure traffic flow. Airports that rely on dependent runways in their daily operation await serious congestion problems if no coordination between arrival and departure management will be initiated soon. Therefore, this research aimed to increase runway configuration capacity at airports that experience interference between arrival and departure capacity due to the use of dependent arrival and departure runways by developing and exploring multiple concepts for a coordination mechanism between Arrival and Departure Management.

Graduated: November 2020

Robin Vervaat (MSc) – Priority-based flight scheduling in the tactical phase

Years of growth in air travel have meant that, as usage is nearing current capacity, delays are becoming virtually inevitable for air carriers operating in our airspace. Flight delays have a significant impact on airport and airline operations, as well as their cost. As such, tactical planning of the flights has become increasingly important, especially for a hub-operator with many connecting passengers. In collaboration with LVNL, KLM and Amsterdam Airport Schiphol, a novel model is being investigated tasked with the Arrival Sequencing and Scheduling of flights considering (airline) priority criteria. Smarter use is to be made of the available infrastructure in order to increase capacity and decrease delay (costs), however, fairness and equality between stakeholders will still need to be upheld.

Graduated: September 2020

Bas Timmer (BSc) – Analysing inbound sources of information to improve the predictability and accuracy of the landing times

With the growing aviation industry in Europe, efficient use of the inbound capacity becomes even more important. One of the determining factors in capacity is the ability of accurately predict the landing time of aircraft. LVNL systems AAA and ASAP generate their inbound sequence planning based on Estimated Landing Times (ELDT) calculated from a variety of data sources. When CDM was implemented, business rules were put in place to prioritize certain data sources above another based on quality and accuracy. Nowadays, the quality and accuracy of these sources are thought to be different. Reviewing the current business rules is done by analyzing the quality and accuracy of the data sources, and how flight characteristics or procedures can influence the accuracy of the ELDT.

Graduated: August 2020

Max (MSc) – Aircraft noise model validation using noise measurement feedback

One of the current factors limiting the growth of the aviation industry in the Netherlands is the relationship between the aviation sector and local communities around airports. Aircraft noise production is one of the main causes of nuisance in residential areas reported by RIVM. It is therefore, for the aviation industry as a whole, of great importance to gain a better understanding of the methodology of aircraft noise modelling and make improvements on this modelling process if deficiencies in the current model are detected. The validation of the aircraft noise model, using noise measurements taken around the airport, is crucial for the scientific foundation of the model. This scientific foundation is expected to increase the transparency in how noise calculations are performed, which increases community trust in the aviation industry as a whole.

Graduated: July 2020

Ashley Scheenloop (BSc) – Impact of the fleet mix on the outbound capacity at Schiphol Airport

With the future growth in amount of flight movements in the aviation sector, efficient use of the airport resources are getting more and more important. In 2019 it was seen that the declared runway capacity at Schiphol airport is not reached during the outbound peaks. Previous research showed that the aircraft type (Wake turbulence category) influences the runway capacity. With the use the A-CDM principle, the outbound phase at Schiphol airport is analysed. This way the time spent, between the time references (A-CDM Milestones), for each Wake turbulence category is analysed and compared. This will provide an insight on the behaviour of these aircraft types, and indicates a possible significant difference/bottleneck. Besides the active runway combinations are analysed during these outbound peaks.

Graduated: July 2020

Marc Out (BSc) – Reducing the fluctuations on the outbound planning at Amsterdam Airport Schiphol

At Amsterdam Airport Schiphol, the outbound planning is created by the Collaborative Pre-Departure Sequence Planner (CPDSP). Currently, this outbound planning is fluctuating because of frequent updates of the Target Off-Blocks Time (TOBT). Having a dynamical outbound planning could create in a loss of valuable outbound capacity and increasing the risks in regulated flights by EUROCONTROL. To reduce the occurrence of frequent TOBT updates, different business rules have been analyzed for the auto-TOBT update mechanism. This mechanism updates the Target Off-Blocks Time automatically once the inbound flight has an assigned landing runway until the moment the aircraft is in-blocks or the Main Ground Handler updated the TOBT manually. The analyzed business rules had different characteristics related to the frequency of TOBT updates and the accuracy of this target time. Those two main characteristics were required to analyze to be able to have an overview which business rule creates less updates but having the same quality as in the current situation.

Graduated: July 2020

Thijs Scheffers (BSc) – Improving the outbound planning process at Amsterdam Airport Schiphol

To improve the outbound planning process of Schiphol Airport, the frequency, availability and accuracy of Estimated Landing Time (ELDT) data has been investigated. Special attention is placed on the information sharing and the calculation of the ELDT, that is calculated by Amsterdam Advanced Air traffic control system (AAA). In addition, the search for new and accurate data sources to estimate the landing time is a continuous effort. As of November, 2018, a new arrival management (AMAN) system is in use at LVNL, called Advanced Schiphol Arrival Planner (ASAP), which replaces the old arrival system, called Inbound Planning (IBP). The new AMAN has implemented different internal characteristics and processes, such as a new trajectory predictor and planning algorithm. Therefore, the new AMAN could potentially provide more accurate arrival time predictions. Both systems are compared to identify their performance.

Graduated: April 2020

Matthijs Ottenhoff (MSc) – Wind and Trajectory Uncertainty in a 4D Trajectory Management Interface

With air traffic numbers increasing, a shift in the Air Traffic Management system towards 4D flight plans, where an aircraft trajectory is pre-planned in both time and space, is foreseen. When these pre-planned trajectories are subsequently executed, unforeseen airspace perturbations, such as weather, sequencing and changing airspace constraints, will inevitably require small changes in the trajectories to be made by the air traffic controller. This perturbation management control task will consist of ensuring a safe airspace while adhering to the strict time constraints imposed by the 4D flight plan. In collaboration with LVNL, a decision support interface was designed and evaluated with the aim of visualizing possible conflict resolutions in the 4D domain. A special focus was put on the integration of wind and trajectory uncertainty information into the interface.

Graduated: March 2020

Eline Bakker (MSc) – Design and Evaluation of a Visual Interface for an En-Route Air Traffic Control Merging Task

In the past decades, the air traffic growth has resulted in increasingly complex situations involving more aircraft simultaneously. In order to guarantee safety is maintained within the increasingly crowded airspace, new solutions are expected. In collaboration with the LVNL, an Inbound Traffic Support System interface was developed. The goal of the interface is to visualize the possible solutions of an area controller’s task of merging aircraft towards a restricted waypoint in the current work domain, such that the impact of decisions made can be foreseen.  By showing the affordances of the work domain, the display keeps the air traffic controller as the active decision maker rather than issuing advisories.

Graduated: October 2019 

Femke Mollema (BSc) – Creating more capacity at Amsterdam Airport Schiphol by reducing planning inefficiencies amongst KLM, LVNL and AAS

As of today, the aviation parties at Amsterdam Airport Schiphol are connected to the European network managed by Eurocontrol NMOC (Network Manager Operation Centre) through its local Airport CDM (Collaborative Decision Making) process. Within the Dutch aviation industry, many stakeholders are involved in the air traffic process, of which three of the main stakeholders are KLM, AAS and the LVNL. Each stakeholder can influence a certain part of the air traffic process, for which they create their own planning. Other parts of the air traffic process, over which a stakeholder has no control, are influenced, and planned on, by the remaining stakeholders. Since the air traffic process is a continuous cycle all stakeholders involved carry dependencies on one another, which also influences the planning each stakeholder makes. To succeed both the overall air traffic process and thus the stakeholders’ individual process, a collaboration among stakeholders is required. The goal of this research is to determine which planning inefficiencies may arise as a result of the different points of interests of the stakeholders within the Dutch aviation sector. By determining these inefficiencies, it can be researched how these can be eliminated, which could eventually benefit the capacity problem. For the purpose of this research the focus will primarily be on KLM flights.

Graduated: August 2019

Sybren Kuiper (BSc) – Evaluation of plan stability deviations in the flow at Schiphol airport

Over the last years Schiphol has experienced a growth in aircraft movements and exchange of narrow body aircraft for wide body aircraft. The infrastructure has been unable to change at the same pace increasing the pressure on the ground operations capacity and forcing the growth into the off-peaks moments where free infrastructural capacity was available. By growing in the off peaks a new challenge arose. The unused capacity was of essential value in the system plan stability. It offered flexibility that could be used to recuperate from planning deviations. The situation created, can cause a deviation from the plan to trigger a domino through the day that cannot be halted because there is no recuperation space. To stop this effect, it is essential to perform research into the current situation of the plan stability, and the exact causes that start or continue the domino effect. To do this the research will answer the following research question: “What are the opportunities for Amsterdam Airport Schiphol and the other KDC stakeholders to improve the airside ground operational plan stability of the airport?”

Graduated: August 2019

Kyara Metz (BSc) – Evaluation of peak hour capacity at Schiphol and similar airports to determine common capacity management practices

According to EUROCONTROL, Schiphol has the most significant contribution on global ATFM airport delays of all the European Airports; weather and airport capacity were targeted as primary cause of delays. Therefore, this research investigates the potential uses of holding buffers of inbound flows at Amsterdam Schiphol Airport (AAS) during peak hour of operations to absorb delays; special attention is placed on analysing the current methods employed by Schiphol and other Airports uses holding buffer not as a reactive resource for ATCs but a everyday use tool to maximize throughput on runway.

Both quantitative and qualitative research has been used to investigate which operational possibilities LVNL has to buffer inbound traffic in the Dutch airspace and to what extent these buffers can be used in managing the operational inbound peak capacity. To determine the current linear buffer capacity, 20,000 flights from July 2018 were analysed.

Graduated: August 2019

Davey Hooijmeijer (MSc) – Schiphol noise analysis for fixed arrival routings 

In this thesis research, dutch aircraft noise model (NRM) calculations are compared to measurements to analyse the aircraft classification used in the model. To do so, a new implementation of the model has been set up to calculate with LVNL trackdata and NOMOS measurement data. First, the classification approach is analysed as prescribed, which shows clustering of aircraft types when compared to measurements. After, the theoretical input data as prescribed for the model is assessed and replaced by real data for each type specific. This leads to improvements of the model calculations when compared to measurements and shows that aircraft-specific flight-information would improve the model significantly. Concluding, it is shown that aircraft noise models strongly rely on the quality of the input data. Current input data shows certain mismatches with respect to reality, resulting in differences between calculations and measurements. However, the calculations can give valuable insights in the effect of operations on the overall noise exposure.

Graduated: July 2019

Anouk Hollebeek (BSc) – Evaluation of AMAN implementation to establish improvements in the arrival efficiency

A new Arrival Management system, called Advanced Schiphol Arrival Planner (ASAP), was implemented in 2018 to regulate the arrival traffic flows at Amsterdam Schiphol Airport (AAS). ASAP aims to be an assisting support tool for the Approach Planner (APLN)  to monitor and safety merge inbound traffic flows in the Dutch Terminal Control Area (TMA). To validate the implementation of ASAP diverse analysis have been run. This work describes some recent insights and findings regarding the performance and interaction between users (ATCs) and ASAP. Particular attention is placed to establish the moment and type of interaction between the different users. The performance of the tool was evaluated using four main performance indicators; Expected Approach Time (EAT) adherence, slot adherence, holding ratio, influence of APLN.

Graduated: July 2019

Flore Wassenberg (BSc) – D-1 process impact evaluation

In 2018, it was started as part of the development of the capacity management function was the D-1 project. The D-1 project intends to provide an operational and capacity plan before the day of operation. Within the D-1 project team there is a need to validate the quality of the predicted traffic demand, because the prediction generated was not quantitatively evaluated afterward. To explore the reliability and usability of the traffic demand prediction at D-1, a bachelor thesis research has been performed. This research has been done by means of comparing the D-1 traffic demand prediction with the demand on the day of operation. The last submitted flight plans at D0 have been compared to the data predicted on D-1. The sample used contains data that was generated during a period of three months of the D-1 project trial. The research concludes that the traffic demand prediction is for parts not accurate enough to support the D-1 decision making process.

Graduated: July 2019

Casper Moll (BSc) – Capacity analysis of airport slot planning and air traffic demand

According to Eurocontrol,  in 2017 Schiphol Airport was the airport with the biggest inbound ATFM delay of all major airports in Europe. One of the reasons that could cause the inbound ATFM delay is the so called ‘bunching’ effect at the border of the Dutch airspace. The objective of this research is to determine if the encountered planned bunches at -3-hour planning phase has an impact on the airport slot planning. This research focusses on the airport slot declaration and the planned demand based on the last filed flight plans, covering a period from the 25th of October 2017 till the 27th of October 2018. The analysis  contains 254,000 arriving flights in both winter and summer season. The analysis determines to which extent the bunching occurs in the airport slot declaration, and at the border of the Dutch airspace. The results reveal that bunching are present in the pre-planning phase within the airport slot declaration and is caused by the skewness within the airport slot-brackets. The analyses render similar patterns in which overdemand occurs within the time-brackets. The subsequent relationship between the airport slot planning and air traffic demand is around 48%, within the assumptions and limitations of the research. This means that 48% of the flights which are planned in a period with overdemand within the airport slot allocation, also tend to arrive in a period with overdemand at the border of the the Dutch airspace.

Graduated: June 2019

Marc Riebeek (BSc) – Comparison of airport slots and schedule & flight planning

Amsterdam Airport Schiphol is the airport with the most airport Air Traffic Flow Management (ATFM) delay in Europe in 2017. One of the causes of the ATFM delay is that airlines do not adhere to their allocated airport slots. With providing insights into deviation between flight schedules or flight plan and airport slot, causes of deviating to the airport slot are identified. This research is done by means of analysing the deviations to identify the characteristics of the deviations. In addition, interviews with airlines and a ground handler and literature about possible causes are used to provide insights. The main findings are that ~ 3.3% of the flight schedules deviate from the airport slot. The deviation between flight plan and airport slot is around 67% of arriving flights. This deviation of flight plans means that the estimated in block time (EIBT), deviates more than 5 minutes from the airport slot. Both in absolute amount and relative percentage, general aviation and cargo airlines are the business models that cause the most deviation between flight schedule and airport slot. An agreement between the general aviation ground handlers and the typical business of cargo are the main reasons for the deviation. The full-service carriers and low-cost carriers cause in absolute number, the most deviation between the EIBT based on flight plan and airport slots. If the EIBT, based on the flight plan, is earlier than the airport slot, more than 90% of these arrivals are planned earlier because of schedule buffers.

Graduated: June 2019

Mats Dirkzwager (MSc) – Design and Evaluation of a Visual Interface for Separation Support in Time-Based Approach Air Traffic Control

On final approach, an Approach (APP) Air Traffic Controller (ATCo) is responsible for keeping sufficient separation between aircraft lining up on the ILS. The current industry standard is to separate these aircraft with a minimum distance, called Distance-Based Separation or DBS. European regulation requires all European airports to implement separation based on time (TBS) before 2024. Due to this implementation, effectively changing the APP ATC task from a geometrical to a time-based problem, and because of further complications such as the European Re-categorisation of aircraft types, experts fear that the theoretical gains attainable by using TBS will not be fully realised. In this research, a display tool concept to aid APP ATCos in realising the full potential of TBS, the Ideal Turn-In Point (ITIP) display is designed and evaluated with respect to the current state of the art. The ITIP display assists controllers in selecting optimal approach strategies starting from the moment aircraft enter the Terminal Control Area. The display aims to assist the operator by showing the possibilities and restrictions in the system rather than giving (restricting) advisories. In an initial proof-of-concept experiment, comparing the ITIP display to the current industry state of the art display, promising results were found; the ITIP display was shown to maintain safety and increase efficiency, whilst maintaining controller workload. The current industry state of the art display is a tool designed by the National Air Traffic Services, currently operational at London Heathrow Airport.

Graduated: June 2019

Marc Voogt (BSc) – Operational benefits since the connection of Amsterdam Airport Schiphol with the Network Manager.

Key to enabling growth at Schiphol without compromising on safety, efficiency and the environment is to increase the predictability of traffic flows. Procedures put in place by Collaborative Decision Making (CDM) support predictable traffic flows not only at Schiphol but also in the surrounding airspace of Central Europe…Research is carried out into the effectiveness of CDM since the data -connection and the impact on operational partners at Schiphol and in the EUROCONTROL  network. The data-connection is identified to have improved the accuracy of take-off time predictions at Schiphol considerably with an average monthly increase of 6% of all departing movements regarded as having a predictable take-off time. Towards the network this take-off time predictability has increased significantly. In relation to similar major-hub airports, the increased take-off time predictability and the exchange of more accurate operational planning data between Schiphol and the NMOC are identified to have contributed to the significantly high compliance to imposed take-off times (93% of all departing movements) supporting stable Network Management. Although significant increases in delay throughout the EUROCONTROL network are increasingly affecting a stable planning of aircraft parking stands at Schiphol, indications for a reduction in stand-delay and other KPIs related to improved flow-efficiency at the airport are identified.

Graduated: April 2019

Tessa Rietema (BSc) – Capacity requirements analysis of civil air traffic in military controlled airspace

The determination of the capacity of the Lelystad Terminal Manoeuvring Area (TMA) is complex and brings different challenges. The opening of Lelystad airport for civil air traffic is the motivation to perform research into the capacity of the Lelystad TMA…The aim of this research is to help CLSK to determine the capacity factors and the capacity of the Lelystad TMA…By means of interviews and expert sessions with operational experts of CLSK, data is created to use during the research. With the data, the volume and capacity of the TMA is calculated. After this, a bottleneck analysis is conducted for the capacity of the handling process. The bottleneck in the handling process is the airport with its aircraft stands. After this, the TMA is the limiting capacity compared with the runway. Additionally, the annual maximum flight movements of 4,000 and 10,000 is feasible with the structure of the TMA. When the airport becomes operational for commercial traffic, the established capacity must be validated

Graduated: February 2019

Bas Broekstra (BSc) – Impact of Special Events on Airspace

Large-scale (e.g. Tour de France, Nuclear Security Summit, etc) or other special events can mean a temporary  increase in (concentrated) traffic in the airspace. These interruptions of normal operations can have impact on the airspace capacity and air traffic controller workload. The objectives of the research is to analyse and evaluate the impact of past events, to provide insight in the capacity impact of an event. To do so, operational requirements of different events are evaluated and analysed, with the aim to provide possible improvements to be better prepared for future events. Improvement could include procedural recommendations to manage special events in the airspace, to ensure that capacity is managed in efficient ways in the future. How do current procedures, to determine the impact of special events on airspace capacity, justify the impact on operations to stakeholders in Dutch airspace?

Graduated: July 2018

Marc Eijkens (BSc) – Analysis of Vertical Flight Trajectory Efficiency

The objective of this research is to analyse the effects of the current hand-over conditions on both horizontal and vertical flight trajectory efficiency. This analysis provides insight into the significance of how the current hand-over conditions affect operational efficiency. It will present an understanding of the impact on air traffic controller (ATCo) workload when this additional coordination is carried out. Besides analysing the impact on operational efficiency and ATCo workload, the research will provide possible solutions to the problem at hand. Solutions could range from procedural changes to technical innovations which will not negatively impact/increase controller workload.

Graduated: July 2018

Gijs Peters (BSc) – Impact Analysis on the Airside Infrastructure at Schiphol

The airside infrastructure layout of AAS is very complicated, and bottlenecks are easily formed. With this growing amount of movements, bottlenecks will occur more often and influence the capacity. Every stakeholder has its own perspective on the current problems and cooperation is difficult to achieve. The research gives an overview of the current bottlenecks at the runways, taxiways and gate/buffer areas to create more awareness of the seriousness of the problem. More awareness will stimulate a better cooperation between the main stakeholders of AAS’ airside infrastructure. Also, a list of possible solutions is created.

Graduated: July 2018

Martijn Ringelberg (BSc) – Airline Strategies’ Impact on Gate Occupancy

How do airline characteristics, ranging from business model differences to variation in actual procedures, affect AAS airside capacity? Schiphol airport is reaching its limit based on the cap of 500.000 movements per year. For reaching this amount of movements a lot of capacity constraints have already been tackled, not all of them however. There are numerous airlines operating at Schiphol, and all of these airlines have various differences and equalities ranging from differences between business models to differences between pilots. The fleet size or structure of an airline for example can impact the maximum number of movements per hour of a runway as bigger aircraft need to have more separation than smaller aircraft. Another issue is the communication between airlines and airport. This may lead to congestion as the airport wouldn’t be able to plan the gate capacity well in advance. When the impacts of airline strategies are known in more detail, AAS and LVNL would be able to plan accordingly to have less capacity congestion.

Graduated: July 2018

Roel Wouters (BSc) – Impact of Local A-CDM on the Operational Efficiency at Mainport Schiphol

AAS is at the final stage of having Airport- collaborative decision making (A-CDM) completely implemented. The last step is to connect the network manager and then AAS will be a CDM airport. The network manager is currently not yet connected and, therefore, not taken into account in this study since there is not any data available yet. Local A-CDM is currently implemented at AAS which includes the four other main stakeholders (Airport operator, Aircraft operator, ATC and ground handlers). Local A-CDM should improve the stakeholders’ operational efficiency by improving the predictability and decision making.  It is likely that A-CDM has been beneficial for the operation of each involved stakeholder at AAS. However, for all stakeholders it is still uncertain how much the operational efficiency has improved thanks to the implementation of local A-CDM. The aim of this study is researching how local A-CDM has exactly improved the operation’s efficiency for each involved A-CDM stakeholder at Mainport Schiphol until now, and what the exact benefits are.

Graduated: July 2018

Huib de Jong (BSc) – How can Schiphol transition to use of APOC in an effective way?

ATC controllers are respected for their high-performance jobs, training is consistent and on high quality level, still the individual controller has the opportunity to guide air traffic in the most efficient way for that moment. An analysis of ATC decision making (taxiway, gates, runway usage, approach and take-off routing), finding deviations and variations in the operation, should determine the current way of working and should form the basis to work towards APOC. In APOC, a key difference between the current situation is the way of information sharing and availability, this difference with the current situation should be analyzed, providing the insight how to transition towards the use of APOC. The results must provide how the current decision-making process impacts capacity and to what extent can these deviations and variations be reduced when APOC is used. Furthermore, what are benefits and what are the requirements to transition to this future situation. In addition, also maintaining sufficient flexibility in the operations after the decisions have been made.

Graduated: March 2018

Remsey Kanis (BSc) – Analyses of deviations and variations in the ground operations due to runway changes

Schiphol has the most runways in Europe with respect to major hub airports, this does not automatically translate to the highest ATMs. During the day runway use is changed, primarily because of the noise restrictions surrounding Schiphol. An analysis of the impact on the capacity on the ground and in air, is needed to determine, how this already complex change of runways also increases the complexity in other parts of the system. Included in the analysis the effect on TATs can be determined possibly through A-CDM data, also information from the ORS (Omgevingsraad Schiphol) must be considered as input. The results must provide an effect analysis on specific parts of the system and the reasoning, the related stakeholders need to be covered also the cost and benefits in operational sense need to be addressed.

Graduated: March 2018

Joep Boekhout (BSc) – Analysis of the effectiveness of the limitation/regulations in controlling airspace towards and from Schiphol

Air traffic controllers find the most efficient way to align aircraft towards the runway, maintaining separation requirements, trying to prevent delays, choosing the most fuel-efficient routes for airlines from and to the airport. Although in some cases regulations in the airspace are deemed necessary to cope with an increase in demand, on top of that pilots (airlines) tend to defeat the system by asking for directs (deviations), instead of following the rest. In addition, relaxing some airspace constraints did not have the effect of a higher utilisation of the airspace. The analysis should provide insight in the effectiveness of limitation/regulations used in the airspace. Possible input can be an aircraft priority study (KLM), that provides the airline with information which aircraft to speed up or slow down. The results of the research must provide air traffic controller with the impact of certain regulations and also airspace users with the insight on how their decisions impact the whole system. Included should be at least a list of the most used regulations with their impact/effectiveness and deviations by users including their impact as well. The customer wants to get insight in the current effectiveness of Network Manager regulations, and in particular the effect of airline/pilot behaviour on the effectiveness of regulations.

Graduated: March 2018

Eneko Rodríguez (MSc) – Investigating the effects of Flexible Use of Airspace availability and plannability on fuel efficiency

All military airspace in the Amsterdam Flight Information Region (FIR) falls under the concept of Flexible Use of Airspace (FUA), which no longer considers airspace as purely ‘civil’ or ‘military’ but rather as a continuum to be allocated temporarily according to user requirements. The complexity of FUA lies in the challenge to harmonize the airspace usage according to these requirements, which largely contradict one another. On the one hand, the military user benefits from using the airspace flexibly, as the effectiveness of their missions and exercises depend on the availability of weather and equipment conditions. On the other hand, the civil users benefit from a high plannability to efficiently execute their operations. By modeling the fuel consumption of civil traffic, the effects of availability and plannability of the FUA in Amsterdam FIR can be computed. While FUA availability determines the route followed by a flight, FUA plannability determines how early the true trajectory is known. Announcing the FUA usage earlier results in avoiding to carry a surplus fuel, which increases the weight and thus fuel burnt of the aircraft. By understanding these effects, new guidelines of FUA usage and plannability may be proposed in the context of the ongoing Dutch Airspace Redesign Programme.

Graduated: August 2022

Bart Rozendaal (MSc) – A neural network approach in optimising
airport strategy with trajectory prediction

As the airspace is getting increasingly crowded worldwide, the capacity management of airports is more important than ever. To avoid unnecessary and costly delays, it is crucial for airports to have well timed strategies and reliable arrival predictions. To achieve this, airports need accurate long-term trajectory predictions such that arrival times can be estimated with high precision. Countless factors such as weather conditions, restricted fly areas and air traffic control clearances cause route uncertainties, making it difficult to predict long-term trajectories accurately. In this thesis, a bidirectional LSTM recurrent neural network is proposed to solve a sequence-to-sequence learning problem and predict the most likely route flown by the aircraft before take off. The network is trained on historical flight plans only, making it easy to implement. The data exists of incoming flights on Schiphol international airport within Europe. Different Hyperparameters are tested to improve performance of the network.

Graduated: July 2022

Thomas Vermeulen (MSc) – Evaluation and assessment of the performance of the KNMI Schiphol Kansverwachting (SKV) for Mainport Schiphol with respect to wind direction and wind gusts

Accurate weather forecasts are crucial information to regulate the operations at Schiphol Airport. Sudden changes in weather conditions need to be communicated in a fast and efficient way to maintain the safety and efficiency for flight operations. KNMI provides a probabilistic weather forecast, called the Schiphol Kansverwachting (SKV), which is produced using output of numerical weather prediction models in combination with the latest observations and several statistical post-processing tools. In particular information on the wind direction and the wind gusts is highly important to support air traffic control. Relatively large errors could lead to restrictions which were in the end not needed or it could lead to restrictions which were issued too late. This research will evaluate the performance of the SKV of wind direction and wind gusts for three different weather models: HIRLAM, HARMONIE and ECMWF. Quantitative information on the forecasting errors will be identified, but also suggestions for possible improvements on the weather forecasts will be part of the result of this study.

Graduated: July 2022

Wesley Vork (BSc) – Develop sequential steps towards a Multi Airport System (MAS)

Dutch airports have grown significantly over the years. This growth is occurring almost autonomously. No mechanisms have been put in place to strategically balance this growth between Dutch airports, routes, or airspace. Without major reforms, the maximum capacity of the airspace will soon be reached. The relationship between EHLE, EHEH, EHRD and EHAM is under scrutiny. With autonomous growth and without mitigating measures, this will lead to the first airspace bottlenecks in 2023 and contiguous bottlenecks in 2035. By examining how air traffic can be better handled through joint air traffic management, the capacity bottlenecks can be addressed. By conducting a thorough research on the MAS, it will become clear what problem the MAS solves and how this system can be used to solve the capacity bottlenecks.

Graduated: July 2022

Max Aalberse (MSc) – Optimizing the distribution of aircraft over the IAF

Around Schiphol and many other airports the amount of movements allowed is constrained due to the considerable noise pollution from aircraft. For a large part the noise pollution is created by arriving aircraft that are in between the IAF and the RWY. During this period the aircraft are in so called transition. These transition routes are usually already optimized to reduce the noise disturbance to surrounding residents, but due to the positioning of the runways this is not always possible. A different distribution of the aircraft over the IAF could result in less noise disturbance for surrounding residents, but would also increase flight times and fuel usage and therefore an increase in other emissions such as CO₂. The goal of this research is to create a parameterized model that optimally distributes the aircraft over the IAF based on a quantitative trade-off between noise disturbance and CO₂ emissions. Resulting in a model that is potentially able to reduce noise disturbance around airports while keeping the increase in environmental impact at a minimum.

Graduated: June 2022

Edzer Oosterhof (MSc) – Effect of Trajectory Prediction Uncertainty on Debunching of Inbound Air Traffic

With the current growth in air traffic and the resulting developments in terms of environmental issues and noise abatement, the pressure on the Area Control Center (ACC) is growing. On the one hand the Terminal Control Area (TMA) requires arriving traffic to be handed over accurately sequenced and merged, and on the other hand the ACC tries to minimize the miles flown in its sector. At the tactical level, there are Air Traffic Flow Management (ATFM) measures in place for traffic within Europe. However, no such tactical measures exist for traffic from the North Atlantic Tracks, increasing the probability that bunching occurs in the ACC during peak loads. By tactically predicting bunching in the sector and at the Initial Approach Fixes, a concept for debunching should be devised that focusses on airborne delay consumption and sequencing of traffic in the Upper control Areas (UTA) before it enters the Control Area (ACC), decreasing the pressure on the ACC.

Graduated: March 2022

Rebekka van der Grift (MSc) – Aircraft Noise Model Improvement by Calibration of Noise-Power-Distance Values Using Acoustic Measurements

The impact of the aircraft industry on the environment becomes more evident every day. Especially for local communities around the airport, the noise nuisance is an important factor which puts a strain on the capacity of Schiphol mainport. This capacity is based on the noise levels around airports, which are calculated with noise models based of key input parameters. The accuracy of these models is thus of great importance for the Schiphol mainport and the local communities. This research aims to develop a dynamic noise model based on real world aircraft noise measurements taken by NOMOS. The measurements will be used to calibrate certain input parameters to minimise any differences between model and measurements. This method helps to keep the model up to date and validated. Using measurements instead of standard input parameters is expected to increase the accuracy of the model, but also increase the trust of local communities in noise modelling.

Graduated: January 2022

Stephanie Wiechers (MSc) – Design and Evaluation of a Support Tool for Planning Adherence While Holding Inbound Air Traffic

As Schiphol is one of the busiest airport in the world, with tight flight schedules and urban areas that lie under arrival routes, adherence to the time planning is very important. When extreme weather conditions cause delays over the entire arriving fleet, holding stacks are installed at the three Initial Approach Fixes (IAFs) around Schiphol. In the current operational environment, little support is offered to the holding stack controller (ACC) to gain an overview of the effects of speed and wind on the turn times and difference between inbound and outbound leg velocity. With increased support, the controller will be able to make decisions based on representative information and with that, deliver inbound aircraft to Approach (APP). The (expected) resulting increased EAT adherence should lead to more orderly traffic in the TMA, improving capacity and workload.

Graduated: December 2021

Soraya van Beek (MSc) – Improving probabilities of poor visibility and ceiling

In order to optimize the current Schiphol operations, an accurate weather forecast is of great importance. The Royal Netherlands Meteorological Institute (KNMI) provides a probabilistic weather forecast for Low Visibility Procedures (LVPs) to Schiphol, which is computed using deterministic weather models. If these LVPs occur due to low visibility or low ceiling, adjusted capacity and flow restriction are needed within airport operations. Inaccurate forecasting can lead to last-minute restrictions or restrictions when not needed. This research will assess the performance of the probabilistic forecast of visibility and ceiling at Schiphol airport. This will be done for the performance of three different weather models: HIRLAM, HARMONIE and ECMWF. Causes for inaccurate forecasting will be identified and suggestions for improvement of the probabilistic weather forecast will be the end result of this research.

Graduated: October 2021

Gijs Bekkers (BSc) – Improving Operational Plan Preparation for Amsterdam Airport Schiphol

Stakeholder preparation for future operation is currently carried out mostly individually, with limited and mostly untimely access to relevant information. Through identifying and mapping plan development for each involved actor, it is possible to find commonalities and moments of information exchange. Data that could be of relevance for others is often kept private, due to lack of insight in handling by others and lack of knowledge on collective benefits of information-sharing. Using feedback from the Airport’s Operation Centre (APOC) on their Airport Operations Plan (AOP), and from LVNL on their OPS plan, together with expert recommendations, poses improvements for desired information sharing within stakeholders. Optimizing the plan-establishment processes and collectively arranging operational preparation yields benefits for all involved stakeholders. To finally ensure proper execution, data-exchange and arrangements should be constantly monitored using chosen performance indicators.

Graduated: June 2021

Janjaap Wijnker (BSc) – Evaluating the accuracy of information provided by the (D-1) OPS plan

In early 2020 LVNL implemented the OPS plan with the objective to improve the alignment of traffic demand with available capacity. This can be achieved by improving the predictability of the operations and make this transparent and accessible for the stake-holders. Every day the PRE-TACT unit develops an OPS plan for the following operational day. The plan contains two types of information, external factors that might impact the capacity, and recommendations for the most optimal operations. The recommendations are based on the external factors, for example the predicted traffic demand and weather forecast. These two factors contribute to the configuration of runways, and the runway selection determines the required capacity. In order to for LVNL to improve possible deficiencies of the OPS plan, the aim of this research study is to evaluate the accuracy and precision of the predicted traffic demand. The analysis focusses on the difference between predicted and actual traffic demand on a 20 minute resolution. In addition, the implications of factors contributing to the proposed runway configuration will be assessed since the use of different runways could have a significant impact on the capacity.

Graduated: June 2021

Christophe Vakaet (MSc) – Taxi Time Prediction with Classical and Auto Machine Learning at Schiphol Airport

Ground control uses the Departure Sequence Planner (DSP) to optimally plan departures within the operational constraints. The DSP uses an estimated Variable Taxi Time (VTT) to calculate an aircraft’s Target Take-Off Time (TTOT). If the VTT is underestimated flights will not make the determined TTOT, while an overestimation requires the air traffic controller to tactically hold an aircraft. These consequences result in delays, capacity losses, additional workload, and uncertainty. This uncertainty inhibits further operational optimizations. The VTT is currently predicted based on the average taxi times for different gate-runway combinations, wake turbulence categories, deicing procedure, and simplified runway configuration. The goal of this project is to improve VTT predictions by employing machine learning techniques and additional data sources such as traffic density, weather, aircraft type, and more.

Graduated: June 2021

Mathijs Post (MSc) – Air Traffic Flow Management for Amsterdam Airport Schiphol

Air Traffic Flow Management is a measure to optimize the flow of traffic in the European air transportation system. Flights are planned such that these can be operated with as little delay as possible. However, on the day of operation many changes can still happen. Amsterdam Airport Schiphol is the biggest contributor to Airport ATFM Delay in Europe, meaning many flights are delayed because of congestion or other airport related reasons at Schiphol. Besides Airport ATFM Delay, the arrival punctuality of flights at Schiphol can be improved. More insights into the causes and interactions of operational parameters is necessary to understand the main contributors for Airport ATFM Delay and arrival delay. A Bayesian Network is proposed, which is a Probabilistic Graph Model that can find interactions between variables and can identify the operational conditions leading to Airport ATFM Delay and arrival delay.

Graduated: June 2021

Bart Bouwels (MSc) – Air Traffic Management Concept for Off-Idle Continuous Descent Operations at Schiphol

Due to the continued growth of the aviation industry, emission and noise production are at an all-time high. In order to reduce this, conventional approaches could be replaced by continuous descent approaches (CDA). These eliminate all level segments, greatly reducing the average thrust setting, resulting in large reductions in noise and emission production. The problem with almost all CDA procedures is that it makes it much more difficult to predict the future position of an aircraft since it flies its own optimal descent profile, with zero thrust. This results in a need for more separation, greatly reducing the airport capacity. This can largely be solved by using a fixed, constant descent angle for all aircraft. Assessing the robustness of such a concept for a high capacity airport is therefore an important stepping stone towards actual implementation.

Graduated: May 2021

Brian Verhoeven (MSc) – Improving the predictability of Aircraft Induced Lightning (AIL) for Mainport Schiphol

Lightning strikes to aircraft are not uncommon in aviation. Although they are not dangerous anymore, they can still result in damages to the aircraft and delay airline operations. Passengers can get scared from the lightning strike as well. Especially in the region around Amsterdam Schiphol Airport, AIL can occur during fall and winter as well. Estimations are that 90% of the lightning strikes are a result of the aircraft triggering a lightning strike, rather than being accidentally struck. In order to prevent as many strikes as possible, it is thus key to understand this process. Therefore, this research aimed to gain a as complete as possible understanding of the process of AIL and use this knowledge to supply new information about AIL to pilots, as AIL is not included in most standard pilot trainings. This can allow pilots to become more aware of AIL and prevent more lightning strikes and the corresponding inconveniences from occuring.

Finished internship: January 2021

Jeanette Derks (MSc) – Coordinated Arrival and Departure Management for Dependent Runway Operations

The foreseen increase in air traffic movements in combination with eased separation minima between aircraft, redefined by the International Civil Aviation Organization (ICAO) in 2015, is expected to emphasize current runway dependencies at airports even further. As the number of aircraft in vicinity of an airport will increase, conflicting flight paths between arriving aircraft and departing aircraft will become a bigger safety hazard and will affect the efficiency of both the arrival and departure traffic flow. Airports that rely on dependent runways in their daily operation await serious congestion problems if no coordination between arrival and departure management will be initiated soon. Therefore, this research aimed to increase runway configuration capacity at airports that experience interference between arrival and departure capacity due to the use of dependent arrival and departure runways by developing and exploring multiple concepts for a coordination mechanism between Arrival and Departure Management.

Graduated: November 2020

Robin Vervaat (MSc) – Priority-based flight scheduling in the tactical phase

Years of growth in air travel have meant that, as usage is nearing current capacity, delays are becoming virtually inevitable for air carriers operating in our airspace. Flight delays have a significant impact on airport and airline operations, as well as their cost. As such, tactical planning of the flights has become increasingly important, especially for a hub-operator with many connecting passengers. In collaboration with LVNL, KLM and Amsterdam Airport Schiphol, a novel model is being investigated tasked with the Arrival Sequencing and Scheduling of flights considering (airline) priority criteria. Smarter use is to be made of the available infrastructure in order to increase capacity and decrease delay (costs), however, fairness and equality between stakeholders will still need to be upheld.

Graduated: September 2020

Bas Timmer (BSc) – Analysing inbound sources of information to improve the predictability and accuracy of the landing times

With the growing aviation industry in Europe, efficient use of the inbound capacity becomes even more important. One of the determining factors in capacity is the ability of accurately predict the landing time of aircraft. LVNL systems AAA and ASAP generate their inbound sequence planning based on Estimated Landing Times (ELDT) calculated from a variety of data sources. When CDM was implemented, business rules were put in place to prioritize certain data sources above another based on quality and accuracy. Nowadays, the quality and accuracy of these sources are thought to be different. Reviewing the current business rules is done by analyzing the quality and accuracy of the data sources, and how flight characteristics or procedures can influence the accuracy of the ELDT.

Graduated: August 2020

Max (MSc) – Aircraft noise model validation using noise measurement feedback

One of the current factors limiting the growth of the aviation industry in the Netherlands is the relationship between the aviation sector and local communities around airports. Aircraft noise production is one of the main causes of nuisance in residential areas reported by RIVM. It is therefore, for the aviation industry as a whole, of great importance to gain a better understanding of the methodology of aircraft noise modelling and make improvements on this modelling process if deficiencies in the current model are detected. The validation of the aircraft noise model, using noise measurements taken around the airport, is crucial for the scientific foundation of the model. This scientific foundation is expected to increase the transparency in how noise calculations are performed, which increases community trust in the aviation industry as a whole.

Graduated: July 2020

Ashley Scheenloop (BSc) – Impact of the fleet mix on the outbound capacity at Schiphol Airport

With the future growth in amount of flight movements in the aviation sector, efficient use of the airport resources are getting more and more important. In 2019 it was seen that the declared runway capacity at Schiphol airport is not reached during the outbound peaks. Previous research showed that the aircraft type (Wake turbulence category) influences the runway capacity. With the use the A-CDM principle, the outbound phase at Schiphol airport is analysed. This way the time spent, between the time references (A-CDM Milestones), for each Wake turbulence category is analysed and compared. This will provide an insight on the behaviour of these aircraft types, and indicates a possible significant difference/bottleneck. Besides the active runway combinations are analysed during these outbound peaks.

Graduated: July 2020

Marc Out (BSc) – Reducing the fluctuations on the outbound planning at Amsterdam Airport Schiphol

At Amsterdam Airport Schiphol, the outbound planning is created by the Collaborative Pre-Departure Sequence Planner (CPDSP). Currently, this outbound planning is fluctuating because of frequent updates of the Target Off-Blocks Time (TOBT). Having a dynamical outbound planning could create in a loss of valuable outbound capacity and increasing the risks in regulated flights by EUROCONTROL. To reduce the occurrence of frequent TOBT updates, different business rules have been analyzed for the auto-TOBT update mechanism. This mechanism updates the Target Off-Blocks Time automatically once the inbound flight has an assigned landing runway until the moment the aircraft is in-blocks or the Main Ground Handler updated the TOBT manually. The analyzed business rules had different characteristics related to the frequency of TOBT updates and the accuracy of this target time. Those two main characteristics were required to analyze to be able to have an overview which business rule creates less updates but having the same quality as in the current situation.

Graduated: July 2020

Thijs Scheffers (BSc) – Improving the outbound planning process at Amsterdam Airport Schiphol

To improve the outbound planning process of Schiphol Airport, the frequency, availability and accuracy of Estimated Landing Time (ELDT) data has been investigated. Special attention is placed on the information sharing and the calculation of the ELDT, that is calculated by Amsterdam Advanced Air traffic control system (AAA). In addition, the search for new and accurate data sources to estimate the landing time is a continuous effort. As of November, 2018, a new arrival management (AMAN) system is in use at LVNL, called Advanced Schiphol Arrival Planner (ASAP), which replaces the old arrival system, called Inbound Planning (IBP). The new AMAN has implemented different internal characteristics and processes, such as a new trajectory predictor and planning algorithm. Therefore, the new AMAN could potentially provide more accurate arrival time predictions. Both systems are compared to identify their performance.

Graduated: April 2020

Matthijs Ottenhoff (MSc) – Wind and Trajectory Uncertainty in a 4D Trajectory Management Interface

With air traffic numbers increasing, a shift in the Air Traffic Management system towards 4D flight plans, where an aircraft trajectory is pre-planned in both time and space, is foreseen. When these pre-planned trajectories are subsequently executed, unforeseen airspace perturbations, such as weather, sequencing and changing airspace constraints, will inevitably require small changes in the trajectories to be made by the air traffic controller. This perturbation management control task will consist of ensuring a safe airspace while adhering to the strict time constraints imposed by the 4D flight plan. In collaboration with LVNL, a decision support interface was designed and evaluated with the aim of visualizing possible conflict resolutions in the 4D domain. A special focus was put on the integration of wind and trajectory uncertainty information into the interface.

Graduated: March 2020

Eline Bakker (MSc) – Design and Evaluation of a Visual Interface for an En-Route Air Traffic Control Merging Task

In the past decades, the air traffic growth has resulted in increasingly complex situations involving more aircraft simultaneously. In order to guarantee safety is maintained within the increasingly crowded airspace, new solutions are expected. In collaboration with the LVNL, an Inbound Traffic Support System interface was developed. The goal of the interface is to visualize the possible solutions of an area controller’s task of merging aircraft towards a restricted waypoint in the current work domain, such that the impact of decisions made can be foreseen.  By showing the affordances of the work domain, the display keeps the air traffic controller as the active decision maker rather than issuing advisories.

Graduated: October 2019 

Femke Mollema (BSc) – Creating more capacity at Amsterdam Airport Schiphol by reducing planning inefficiencies amongst KLM, LVNL and AAS

As of today, the aviation parties at Amsterdam Airport Schiphol are connected to the European network managed by Eurocontrol NMOC (Network Manager Operation Centre) through its local Airport CDM (Collaborative Decision Making) process. Within the Dutch aviation industry, many stakeholders are involved in the air traffic process, of which three of the main stakeholders are KLM, AAS and the LVNL. Each stakeholder can influence a certain part of the air traffic process, for which they create their own planning. Other parts of the air traffic process, over which a stakeholder has no control, are influenced, and planned on, by the remaining stakeholders. Since the air traffic process is a continuous cycle all stakeholders involved carry dependencies on one another, which also influences the planning each stakeholder makes. To succeed both the overall air traffic process and thus the stakeholders’ individual process, a collaboration among stakeholders is required. The goal of this research is to determine which planning inefficiencies may arise as a result of the different points of interests of the stakeholders within the Dutch aviation sector. By determining these inefficiencies, it can be researched how these can be eliminated, which could eventually benefit the capacity problem. For the purpose of this research the focus will primarily be on KLM flights.

Graduated: August 2019

Sybren Kuiper (BSc) – Evaluation of plan stability deviations in the flow at Schiphol airport

Over the last years Schiphol has experienced a growth in aircraft movements and exchange of narrow body aircraft for wide body aircraft. The infrastructure has been unable to change at the same pace increasing the pressure on the ground operations capacity and forcing the growth into the off-peaks moments where free infrastructural capacity was available. By growing in the off peaks a new challenge arose. The unused capacity was of essential value in the system plan stability. It offered flexibility that could be used to recuperate from planning deviations. The situation created, can cause a deviation from the plan to trigger a domino through the day that cannot be halted because there is no recuperation space. To stop this effect, it is essential to perform research into the current situation of the plan stability, and the exact causes that start or continue the domino effect. To do this the research will answer the following research question: “What are the opportunities for Amsterdam Airport Schiphol and the other KDC stakeholders to improve the airside ground operational plan stability of the airport?”

Graduated: August 2019

Kyara Metz (BSc) – Evaluation of peak hour capacity at Schiphol and similar airports to determine common capacity management practices

According to EUROCONTROL, Schiphol has the most significant contribution on global ATFM airport delays of all the European Airports; weather and airport capacity were targeted as primary cause of delays. Therefore, this research investigates the potential uses of holding buffers of inbound flows at Amsterdam Schiphol Airport (AAS) during peak hour of operations to absorb delays; special attention is placed on analysing the current methods employed by Schiphol and other Airports uses holding buffer not as a reactive resource for ATCs but a everyday use tool to maximize throughput on runway.

Both quantitative and qualitative research has been used to investigate which operational possibilities LVNL has to buffer inbound traffic in the Dutch airspace and to what extent these buffers can be used in managing the operational inbound peak capacity. To determine the current linear buffer capacity, 20,000 flights from July 2018 were analysed.

Graduated: August 2019

Davey Hooijmeijer (MSc) – Schiphol noise analysis for fixed arrival routings 

In this thesis research, dutch aircraft noise model (NRM) calculations are compared to measurements to analyse the aircraft classification used in the model. To do so, a new implementation of the model has been set up to calculate with LVNL trackdata and NOMOS measurement data. First, the classification approach is analysed as prescribed, which shows clustering of aircraft types when compared to measurements. After, the theoretical input data as prescribed for the model is assessed and replaced by real data for each type specific. This leads to improvements of the model calculations when compared to measurements and shows that aircraft-specific flight-information would improve the model significantly. Concluding, it is shown that aircraft noise models strongly rely on the quality of the input data. Current input data shows certain mismatches with respect to reality, resulting in differences between calculations and measurements. However, the calculations can give valuable insights in the effect of operations on the overall noise exposure.

Graduated: July 2019

Anouk Hollebeek (BSc) – Evaluation of AMAN implementation to establish improvements in the arrival efficiency

A new Arrival Management system, called Advanced Schiphol Arrival Planner (ASAP), was implemented in 2018 to regulate the arrival traffic flows at Amsterdam Schiphol Airport (AAS). ASAP aims to be an assisting support tool for the Approach Planner (APLN)  to monitor and safety merge inbound traffic flows in the Dutch Terminal Control Area (TMA). To validate the implementation of ASAP diverse analysis have been run. This work describes some recent insights and findings regarding the performance and interaction between users (ATCs) and ASAP. Particular attention is placed to establish the moment and type of interaction between the different users. The performance of the tool was evaluated using four main performance indicators; Expected Approach Time (EAT) adherence, slot adherence, holding ratio, influence of APLN.

Graduated: July 2019

Flore Wassenberg (BSc) – D-1 process impact evaluation

In 2018, it was started as part of the development of the capacity management function was the D-1 project. The D-1 project intends to provide an operational and capacity plan before the day of operation. Within the D-1 project team there is a need to validate the quality of the predicted traffic demand, because the prediction generated was not quantitatively evaluated afterward. To explore the reliability and usability of the traffic demand prediction at D-1, a bachelor thesis research has been performed. This research has been done by means of comparing the D-1 traffic demand prediction with the demand on the day of operation. The last submitted flight plans at D0 have been compared to the data predicted on D-1. The sample used contains data that was generated during a period of three months of the D-1 project trial. The research concludes that the traffic demand prediction is for parts not accurate enough to support the D-1 decision making process.

Graduated: July 2019

Casper Moll (BSc) – Capacity analysis of airport slot planning and air traffic demand

According to Eurocontrol,  in 2017 Schiphol Airport was the airport with the biggest inbound ATFM delay of all major airports in Europe. One of the reasons that could cause the inbound ATFM delay is the so called ‘bunching’ effect at the border of the Dutch airspace. The objective of this research is to determine if the encountered planned bunches at -3-hour planning phase has an impact on the airport slot planning. This research focusses on the airport slot declaration and the planned demand based on the last filed flight plans, covering a period from the 25th of October 2017 till the 27th of October 2018. The analysis  contains 254,000 arriving flights in both winter and summer season. The analysis determines to which extent the bunching occurs in the airport slot declaration, and at the border of the Dutch airspace. The results reveal that bunching are present in the pre-planning phase within the airport slot declaration and is caused by the skewness within the airport slot-brackets. The analyses render similar patterns in which overdemand occurs within the time-brackets. The subsequent relationship between the airport slot planning and air traffic demand is around 48%, within the assumptions and limitations of the research. This means that 48% of the flights which are planned in a period with overdemand within the airport slot allocation, also tend to arrive in a period with overdemand at the border of the the Dutch airspace.

Graduated: June 2019

Marc Riebeek (BSc) – Comparison of airport slots and schedule & flight planning

Amsterdam Airport Schiphol is the airport with the most airport Air Traffic Flow Management (ATFM) delay in Europe in 2017. One of the causes of the ATFM delay is that airlines do not adhere to their allocated airport slots. With providing insights into deviation between flight schedules or flight plan and airport slot, causes of deviating to the airport slot are identified. This research is done by means of analysing the deviations to identify the characteristics of the deviations. In addition, interviews with airlines and a ground handler and literature about possible causes are used to provide insights. The main findings are that ~ 3.3% of the flight schedules deviate from the airport slot. The deviation between flight plan and airport slot is around 67% of arriving flights. This deviation of flight plans means that the estimated in block time (EIBT), deviates more than 5 minutes from the airport slot. Both in absolute amount and relative percentage, general aviation and cargo airlines are the business models that cause the most deviation between flight schedule and airport slot. An agreement between the general aviation ground handlers and the typical business of cargo are the main reasons for the deviation. The full-service carriers and low-cost carriers cause in absolute number, the most deviation between the EIBT based on flight plan and airport slots. If the EIBT, based on the flight plan, is earlier than the airport slot, more than 90% of these arrivals are planned earlier because of schedule buffers.

Graduated: June 2019

Mats Dirkzwager (MSc) – Design and Evaluation of a Visual Interface for Separation Support in Time-Based Approach Air Traffic Control

On final approach, an Approach (APP) Air Traffic Controller (ATCo) is responsible for keeping sufficient separation between aircraft lining up on the ILS. The current industry standard is to separate these aircraft with a minimum distance, called Distance-Based Separation or DBS. European regulation requires all European airports to implement separation based on time (TBS) before 2024. Due to this implementation, effectively changing the APP ATC task from a geometrical to a time-based problem, and because of further complications such as the European Re-categorisation of aircraft types, experts fear that the theoretical gains attainable by using TBS will not be fully realised. In this research, a display tool concept to aid APP ATCos in realising the full potential of TBS, the Ideal Turn-In Point (ITIP) display is designed and evaluated with respect to the current state of the art. The ITIP display assists controllers in selecting optimal approach strategies starting from the moment aircraft enter the Terminal Control Area. The display aims to assist the operator by showing the possibilities and restrictions in the system rather than giving (restricting) advisories. In an initial proof-of-concept experiment, comparing the ITIP display to the current industry state of the art display, promising results were found; the ITIP display was shown to maintain safety and increase efficiency, whilst maintaining controller workload. The current industry state of the art display is a tool designed by the National Air Traffic Services, currently operational at London Heathrow Airport.

Graduated: June 2019

Marc Voogt (BSc) – Operational benefits since the connection of Amsterdam Airport Schiphol with the Network Manager.

Key to enabling growth at Schiphol without compromising on safety, efficiency and the environment is to increase the predictability of traffic flows. Procedures put in place by Collaborative Decision Making (CDM) support predictable traffic flows not only at Schiphol but also in the surrounding airspace of Central Europe…Research is carried out into the effectiveness of CDM since the data -connection and the impact on operational partners at Schiphol and in the EUROCONTROL  network. The data-connection is identified to have improved the accuracy of take-off time predictions at Schiphol considerably with an average monthly increase of 6% of all departing movements regarded as having a predictable take-off time. Towards the network this take-off time predictability has increased significantly. In relation to similar major-hub airports, the increased take-off time predictability and the exchange of more accurate operational planning data between Schiphol and the NMOC are identified to have contributed to the significantly high compliance to imposed take-off times (93% of all departing movements) supporting stable Network Management. Although significant increases in delay throughout the EUROCONTROL network are increasingly affecting a stable planning of aircraft parking stands at Schiphol, indications for a reduction in stand-delay and other KPIs related to improved flow-efficiency at the airport are identified.

Graduated: April 2019

Tessa Rietema (BSc) – Capacity requirements analysis of civil air traffic in military controlled airspace

The determination of the capacity of the Lelystad Terminal Manoeuvring Area (TMA) is complex and brings different challenges. The opening of Lelystad airport for civil air traffic is the motivation to perform research into the capacity of the Lelystad TMA…The aim of this research is to help CLSK to determine the capacity factors and the capacity of the Lelystad TMA…By means of interviews and expert sessions with operational experts of CLSK, data is created to use during the research. With the data, the volume and capacity of the TMA is calculated. After this, a bottleneck analysis is conducted for the capacity of the handling process. The bottleneck in the handling process is the airport with its aircraft stands. After this, the TMA is the limiting capacity compared with the runway. Additionally, the annual maximum flight movements of 4,000 and 10,000 is feasible with the structure of the TMA. When the airport becomes operational for commercial traffic, the established capacity must be validated

Graduated: February 2019

Bas Broekstra (BSc) – Impact of Special Events on Airspace

Large-scale (e.g. Tour de France, Nuclear Security Summit, etc) or other special events can mean a temporary  increase in (concentrated) traffic in the airspace. These interruptions of normal operations can have impact on the airspace capacity and air traffic controller workload. The objectives of the research is to analyse and evaluate the impact of past events, to provide insight in the capacity impact of an event. To do so, operational requirements of different events are evaluated and analysed, with the aim to provide possible improvements to be better prepared for future events. Improvement could include procedural recommendations to manage special events in the airspace, to ensure that capacity is managed in efficient ways in the future. How do current procedures, to determine the impact of special events on airspace capacity, justify the impact on operations to stakeholders in Dutch airspace?

Graduated: July 2018

Marc Eijkens (BSc) – Analysis of Vertical Flight Trajectory Efficiency

The objective of this research is to analyse the effects of the current hand-over conditions on both horizontal and vertical flight trajectory efficiency. This analysis provides insight into the significance of how the current hand-over conditions affect operational efficiency. It will present an understanding of the impact on air traffic controller (ATCo) workload when this additional coordination is carried out. Besides analysing the impact on operational efficiency and ATCo workload, the research will provide possible solutions to the problem at hand. Solutions could range from procedural changes to technical innovations which will not negatively impact/increase controller workload.

Graduated: July 2018

Gijs Peters (BSc) – Impact Analysis on the Airside Infrastructure at Schiphol

The airside infrastructure layout of AAS is very complicated, and bottlenecks are easily formed. With this growing amount of movements, bottlenecks will occur more often and influence the capacity. Every stakeholder has its own perspective on the current problems and cooperation is difficult to achieve. The research gives an overview of the current bottlenecks at the runways, taxiways and gate/buffer areas to create more awareness of the seriousness of the problem. More awareness will stimulate a better cooperation between the main stakeholders of AAS’ airside infrastructure. Also, a list of possible solutions is created.

Graduated: July 2018

Martijn Ringelberg (BSc) – Airline Strategies’ Impact on Gate Occupancy

How do airline characteristics, ranging from business model differences to variation in actual procedures, affect AAS airside capacity? Schiphol airport is reaching its limit based on the cap of 500.000 movements per year. For reaching this amount of movements a lot of capacity constraints have already been tackled, not all of them however. There are numerous airlines operating at Schiphol, and all of these airlines have various differences and equalities ranging from differences between business models to differences between pilots. The fleet size or structure of an airline for example can impact the maximum number of movements per hour of a runway as bigger aircraft need to have more separation than smaller aircraft. Another issue is the communication between airlines and airport. This may lead to congestion as the airport wouldn’t be able to plan the gate capacity well in advance. When the impacts of airline strategies are known in more detail, AAS and LVNL would be able to plan accordingly to have less capacity congestion.

Graduated: July 2018

Roel Wouters (BSc) – Impact of Local A-CDM on the Operational Efficiency at Mainport Schiphol

AAS is at the final stage of having Airport- collaborative decision making (A-CDM) completely implemented. The last step is to connect the network manager and then AAS will be a CDM airport. The network manager is currently not yet connected and, therefore, not taken into account in this study since there is not any data available yet. Local A-CDM is currently implemented at AAS which includes the four other main stakeholders (Airport operator, Aircraft operator, ATC and ground handlers). Local A-CDM should improve the stakeholders’ operational efficiency by improving the predictability and decision making.  It is likely that A-CDM has been beneficial for the operation of each involved stakeholder at AAS. However, for all stakeholders it is still uncertain how much the operational efficiency has improved thanks to the implementation of local A-CDM. The aim of this study is researching how local A-CDM has exactly improved the operation’s efficiency for each involved A-CDM stakeholder at Mainport Schiphol until now, and what the exact benefits are.

Graduated: July 2018

Huib de Jong (BSc) – How can Schiphol transition to use of APOC in an effective way?

ATC controllers are respected for their high-performance jobs, training is consistent and on high quality level, still the individual controller has the opportunity to guide air traffic in the most efficient way for that moment. An analysis of ATC decision making (taxiway, gates, runway usage, approach and take-off routing), finding deviations and variations in the operation, should determine the current way of working and should form the basis to work towards APOC. In APOC, a key difference between the current situation is the way of information sharing and availability, this difference with the current situation should be analyzed, providing the insight how to transition towards the use of APOC. The results must provide how the current decision-making process impacts capacity and to what extent can these deviations and variations be reduced when APOC is used. Furthermore, what are benefits and what are the requirements to transition to this future situation. In addition, also maintaining sufficient flexibility in the operations after the decisions have been made.

Graduated: March 2018

Remsey Kanis (BSc) – Analyses of deviations and variations in the ground operations due to runway changes

Schiphol has the most runways in Europe with respect to major hub airports, this does not automatically translate to the highest ATMs. During the day runway use is changed, primarily because of the noise restrictions surrounding Schiphol. An analysis of the impact on the capacity on the ground and in air, is needed to determine, how this already complex change of runways also increases the complexity in other parts of the system. Included in the analysis the effect on TATs can be determined possibly through A-CDM data, also information from the ORS (Omgevingsraad Schiphol) must be considered as input. The results must provide an effect analysis on specific parts of the system and the reasoning, the related stakeholders need to be covered also the cost and benefits in operational sense need to be addressed.

Graduated: March 2018

Joep Boekhout (BSc) – Analysis of the effectiveness of the limitation/regulations in controlling airspace towards and from Schiphol

Air traffic controllers find the most efficient way to align aircraft towards the runway, maintaining separation requirements, trying to prevent delays, choosing the most fuel-efficient routes for airlines from and to the airport. Although in some cases regulations in the airspace are deemed necessary to cope with an increase in demand, on top of that pilots (airlines) tend to defeat the system by asking for directs (deviations), instead of following the rest. In addition, relaxing some airspace constraints did not have the effect of a higher utilisation of the airspace. The analysis should provide insight in the effectiveness of limitation/regulations used in the airspace. Possible input can be an aircraft priority study (KLM), that provides the airline with information which aircraft to speed up or slow down. The results of the research must provide air traffic controller with the impact of certain regulations and also airspace users with the insight on how their decisions impact the whole system. Included should be at least a list of the most used regulations with their impact/effectiveness and deviations by users including their impact as well. The customer wants to get insight in the current effectiveness of Network Manager regulations, and in particular the effect of airline/pilot behaviour on the effectiveness of regulations.

Graduated: March 2018

Eneko Rodríguez (MSc) – Investigating the effects of Flexible Use of Airspace availability and plannability on fuel efficiency

All military airspace in the Amsterdam Flight Information Region (FIR) falls under the concept of Flexible Use of Airspace (FUA), which no longer considers airspace as purely ‘civil’ or ‘military’ but rather as a continuum to be allocated temporarily according to user requirements. The complexity of FUA lies in the challenge to harmonize the airspace usage according to these requirements, which largely contradict one another. On the one hand, the military user benefits from using the airspace flexibly, as the effectiveness of their missions and exercises depend on the availability of weather and equipment conditions. On the other hand, the civil users benefit from a high plannability to efficiently execute their operations. By modeling the fuel consumption of civil traffic, the effects of availability and plannability of the FUA in Amsterdam FIR can be computed. While FUA availability determines the route followed by a flight, FUA plannability determines how early the true trajectory is known. Announcing the FUA usage earlier results in avoiding to carry a surplus fuel, which increases the weight and thus fuel burnt of the aircraft. By understanding these effects, new guidelines of FUA usage and plannability may be proposed in the context of the ongoing Dutch Airspace Redesign Programme.

Graduated: August 2022

Bart Rozendaal (MSc) – A neural network approach in optimising
airport strategy with trajectory prediction

As the airspace is getting increasingly crowded worldwide, the capacity management of airports is more important than ever. To avoid unnecessary and costly delays, it is crucial for airports to have well timed strategies and reliable arrival predictions. To achieve this, airports need accurate long-term trajectory predictions such that arrival times can be estimated with high precision. Countless factors such as weather conditions, restricted fly areas and air traffic control clearances cause route uncertainties, making it difficult to predict long-term trajectories accurately. In this thesis, a bidirectional LSTM recurrent neural network is proposed to solve a sequence-to-sequence learning problem and predict the most likely route flown by the aircraft before take off. The network is trained on historical flight plans only, making it easy to implement. The data exists of incoming flights on Schiphol international airport within Europe. Different Hyperparameters are tested to improve performance of the network.

Graduated: July 2022

Thomas Vermeulen (MSc) – Evaluation and assessment of the performance of the KNMI Schiphol Kansverwachting (SKV) for Mainport Schiphol with respect to wind direction and wind gusts

Accurate weather forecasts are crucial information to regulate the operations at Schiphol Airport. Sudden changes in weather conditions need to be communicated in a fast and efficient way to maintain the safety and efficiency for flight operations. KNMI provides a probabilistic weather forecast, called the Schiphol Kansverwachting (SKV), which is produced using output of numerical weather prediction models in combination with the latest observations and several statistical post-processing tools. In particular information on the wind direction and the wind gusts is highly important to support air traffic control. Relatively large errors could lead to restrictions which were in the end not needed or it could lead to restrictions which were issued too late. This research will evaluate the performance of the SKV of wind direction and wind gusts for three different weather models: HIRLAM, HARMONIE and ECMWF. Quantitative information on the forecasting errors will be identified, but also suggestions for possible improvements on the weather forecasts will be part of the result of this study.

Graduated: July 2022

Wesley Vork (BSc) – Develop sequential steps towards a Multi Airport System (MAS)

Dutch airports have grown significantly over the years. This growth is occurring almost autonomously. No mechanisms have been put in place to strategically balance this growth between Dutch airports, routes, or airspace. Without major reforms, the maximum capacity of the airspace will soon be reached. The relationship between EHLE, EHEH, EHRD and EHAM is under scrutiny. With autonomous growth and without mitigating measures, this will lead to the first airspace bottlenecks in 2023 and contiguous bottlenecks in 2035. By examining how air traffic can be better handled through joint air traffic management, the capacity bottlenecks can be addressed. By conducting a thorough research on the MAS, it will become clear what problem the MAS solves and how this system can be used to solve the capacity bottlenecks.

Graduated: July 2022

Max Aalberse (MSc) – Optimizing the distribution of aircraft over the IAF

Around Schiphol and many other airports the amount of movements allowed is constrained due to the considerable noise pollution from aircraft. For a large part the noise pollution is created by arriving aircraft that are in between the IAF and the RWY. During this period the aircraft are in so called transition. These transition routes are usually already optimized to reduce the noise disturbance to surrounding residents, but due to the positioning of the runways this is not always possible. A different distribution of the aircraft over the IAF could result in less noise disturbance for surrounding residents, but would also increase flight times and fuel usage and therefore an increase in other emissions such as CO₂. The goal of this research is to create a parameterized model that optimally distributes the aircraft over the IAF based on a quantitative trade-off between noise disturbance and CO₂ emissions. Resulting in a model that is potentially able to reduce noise disturbance around airports while keeping the increase in environmental impact at a minimum.

Graduated: June 2022

Edzer Oosterhof (MSc) – Effect of Trajectory Prediction Uncertainty on Debunching of Inbound Air Traffic

With the current growth in air traffic and the resulting developments in terms of environmental issues and noise abatement, the pressure on the Area Control Center (ACC) is growing. On the one hand the Terminal Control Area (TMA) requires arriving traffic to be handed over accurately sequenced and merged, and on the other hand the ACC tries to minimize the miles flown in its sector. At the tactical level, there are Air Traffic Flow Management (ATFM) measures in place for traffic within Europe. However, no such tactical measures exist for traffic from the North Atlantic Tracks, increasing the probability that bunching occurs in the ACC during peak loads. By tactically predicting bunching in the sector and at the Initial Approach Fixes, a concept for debunching should be devised that focusses on airborne delay consumption and sequencing of traffic in the Upper control Areas (UTA) before it enters the Control Area (ACC), decreasing the pressure on the ACC.

Graduated: March 2022

Rebekka van der Grift (MSc) – Aircraft Noise Model Improvement by Calibration of Noise-Power-Distance Values Using Acoustic Measurements

The impact of the aircraft industry on the environment becomes more evident every day. Especially for local communities around the airport, the noise nuisance is an important factor which puts a strain on the capacity of Schiphol mainport. This capacity is based on the noise levels around airports, which are calculated with noise models based of key input parameters. The accuracy of these models is thus of great importance for the Schiphol mainport and the local communities. This research aims to develop a dynamic noise model based on real world aircraft noise measurements taken by NOMOS. The measurements will be used to calibrate certain input parameters to minimise any differences between model and measurements. This method helps to keep the model up to date and validated. Using measurements instead of standard input parameters is expected to increase the accuracy of the model, but also increase the trust of local communities in noise modelling.

Graduated: January 2022

Stephanie Wiechers (MSc) – Design and Evaluation of a Support Tool for Planning Adherence While Holding Inbound Air Traffic

As Schiphol is one of the busiest airport in the world, with tight flight schedules and urban areas that lie under arrival routes, adherence to the time planning is very important. When extreme weather conditions cause delays over the entire arriving fleet, holding stacks are installed at the three Initial Approach Fixes (IAFs) around Schiphol. In the current operational environment, little support is offered to the holding stack controller (ACC) to gain an overview of the effects of speed and wind on the turn times and difference between inbound and outbound leg velocity. With increased support, the controller will be able to make decisions based on representative information and with that, deliver inbound aircraft to Approach (APP). The (expected) resulting increased EAT adherence should lead to more orderly traffic in the TMA, improving capacity and workload.

Graduated: December 2021

Soraya van Beek (MSc) – Improving probabilities of poor visibility and ceiling

In order to optimize the current Schiphol operations, an accurate weather forecast is of great importance. The Royal Netherlands Meteorological Institute (KNMI) provides a probabilistic weather forecast for Low Visibility Procedures (LVPs) to Schiphol, which is computed using deterministic weather models. If these LVPs occur due to low visibility or low ceiling, adjusted capacity and flow restriction are needed within airport operations. Inaccurate forecasting can lead to last-minute restrictions or restrictions when not needed. This research will assess the performance of the probabilistic forecast of visibility and ceiling at Schiphol airport. This will be done for the performance of three different weather models: HIRLAM, HARMONIE and ECMWF. Causes for inaccurate forecasting will be identified and suggestions for improvement of the probabilistic weather forecast will be the end result of this research.

Graduated: October 2021

Gijs Bekkers (BSc) – Improving Operational Plan Preparation for Amsterdam Airport Schiphol

Stakeholder preparation for future operation is currently carried out mostly individually, with limited and mostly untimely access to relevant information. Through identifying and mapping plan development for each involved actor, it is possible to find commonalities and moments of information exchange. Data that could be of relevance for others is often kept private, due to lack of insight in handling by others and lack of knowledge on collective benefits of information-sharing. Using feedback from the Airport’s Operation Centre (APOC) on their Airport Operations Plan (AOP), and from LVNL on their OPS plan, together with expert recommendations, poses improvements for desired information sharing within stakeholders. Optimizing the plan-establishment processes and collectively arranging operational preparation yields benefits for all involved stakeholders. To finally ensure proper execution, data-exchange and arrangements should be constantly monitored using chosen performance indicators.

Graduated: June 2021

Janjaap Wijnker (BSc) – Evaluating the accuracy of information provided by the (D-1) OPS plan

In early 2020 LVNL implemented the OPS plan with the objective to improve the alignment of traffic demand with available capacity. This can be achieved by improving the predictability of the operations and make this transparent and accessible for the stake-holders. Every day the PRE-TACT unit develops an OPS plan for the following operational day. The plan contains two types of information, external factors that might impact the capacity, and recommendations for the most optimal operations. The recommendations are based on the external factors, for example the predicted traffic demand and weather forecast. These two factors contribute to the configuration of runways, and the runway selection determines the required capacity. In order to for LVNL to improve possible deficiencies of the OPS plan, the aim of this research study is to evaluate the accuracy and precision of the predicted traffic demand. The analysis focusses on the difference between predicted and actual traffic demand on a 20 minute resolution. In addition, the implications of factors contributing to the proposed runway configuration will be assessed since the use of different runways could have a significant impact on the capacity.

Graduated: June 2021

Christophe Vakaet (MSc) – Taxi Time Prediction with Classical and Auto Machine Learning at Schiphol Airport

Ground control uses the Departure Sequence Planner (DSP) to optimally plan departures within the operational constraints. The DSP uses an estimated Variable Taxi Time (VTT) to calculate an aircraft’s Target Take-Off Time (TTOT). If the VTT is underestimated flights will not make the determined TTOT, while an overestimation requires the air traffic controller to tactically hold an aircraft. These consequences result in delays, capacity losses, additional workload, and uncertainty. This uncertainty inhibits further operational optimizations. The VTT is currently predicted based on the average taxi times for different gate-runway combinations, wake turbulence categories, deicing procedure, and simplified runway configuration. The goal of this project is to improve VTT predictions by employing machine learning techniques and additional data sources such as traffic density, weather, aircraft type, and more.

Graduated: June 2021

Mathijs Post (MSc) – Air Traffic Flow Management for Amsterdam Airport Schiphol

Air Traffic Flow Management is a measure to optimize the flow of traffic in the European air transportation system. Flights are planned such that these can be operated with as little delay as possible. However, on the day of operation many changes can still happen. Amsterdam Airport Schiphol is the biggest contributor to Airport ATFM Delay in Europe, meaning many flights are delayed because of congestion or other airport related reasons at Schiphol. Besides Airport ATFM Delay, the arrival punctuality of flights at Schiphol can be improved. More insights into the causes and interactions of operational parameters is necessary to understand the main contributors for Airport ATFM Delay and arrival delay. A Bayesian Network is proposed, which is a Probabilistic Graph Model that can find interactions between variables and can identify the operational conditions leading to Airport ATFM Delay and arrival delay.

Graduated: June 2021

Bart Bouwels (MSc) – Air Traffic Management Concept for Off-Idle Continuous Descent Operations at Schiphol

Due to the continued growth of the aviation industry, emission and noise production are at an all-time high. In order to reduce this, conventional approaches could be replaced by continuous descent approaches (CDA). These eliminate all level segments, greatly reducing the average thrust setting, resulting in large reductions in noise and emission production. The problem with almost all CDA procedures is that it makes it much more difficult to predict the future position of an aircraft since it flies its own optimal descent profile, with zero thrust. This results in a need for more separation, greatly reducing the airport capacity. This can largely be solved by using a fixed, constant descent angle for all aircraft. Assessing the robustness of such a concept for a high capacity airport is therefore an important stepping stone towards actual implementation.

Graduated: May 2021

Brian Verhoeven (MSc) – Improving the predictability of Aircraft Induced Lightning (AIL) for Mainport Schiphol

Lightning strikes to aircraft are not uncommon in aviation. Although they are not dangerous anymore, they can still result in damages to the aircraft and delay airline operations. Passengers can get scared from the lightning strike as well. Especially in the region around Amsterdam Schiphol Airport, AIL can occur during fall and winter as well. Estimations are that 90% of the lightning strikes are a result of the aircraft triggering a lightning strike, rather than being accidentally struck. In order to prevent as many strikes as possible, it is thus key to understand this process. Therefore, this research aimed to gain a as complete as possible understanding of the process of AIL and use this knowledge to supply new information about AIL to pilots, as AIL is not included in most standard pilot trainings. This can allow pilots to become more aware of AIL and prevent more lightning strikes and the corresponding inconveniences from occuring.

Finished internship: January 2021

Jeanette Derks (MSc) – Coordinated Arrival and Departure Management for Dependent Runway Operations

The foreseen increase in air traffic movements in combination with eased separation minima between aircraft, redefined by the International Civil Aviation Organization (ICAO) in 2015, is expected to emphasize current runway dependencies at airports even further. As the number of aircraft in vicinity of an airport will increase, conflicting flight paths between arriving aircraft and departing aircraft will become a bigger safety hazard and will affect the efficiency of both the arrival and departure traffic flow. Airports that rely on dependent runways in their daily operation await serious congestion problems if no coordination between arrival and departure management will be initiated soon. Therefore, this research aimed to increase runway configuration capacity at airports that experience interference between arrival and departure capacity due to the use of dependent arrival and departure runways by developing and exploring multiple concepts for a coordination mechanism between Arrival and Departure Management.

Graduated: November 2020

Robin Vervaat (MSc) – Priority-based flight scheduling in the tactical phase

Years of growth in air travel have meant that, as usage is nearing current capacity, delays are becoming virtually inevitable for air carriers operating in our airspace. Flight delays have a significant impact on airport and airline operations, as well as their cost. As such, tactical planning of the flights has become increasingly important, especially for a hub-operator with many connecting passengers. In collaboration with LVNL, KLM and Amsterdam Airport Schiphol, a novel model is being investigated tasked with the Arrival Sequencing and Scheduling of flights considering (airline) priority criteria. Smarter use is to be made of the available infrastructure in order to increase capacity and decrease delay (costs), however, fairness and equality between stakeholders will still need to be upheld.

Graduated: September 2020

Bas Timmer (BSc) – Analysing inbound sources of information to improve the predictability and accuracy of the landing times

With the growing aviation industry in Europe, efficient use of the inbound capacity becomes even more important. One of the determining factors in capacity is the ability of accurately predict the landing time of aircraft. LVNL systems AAA and ASAP generate their inbound sequence planning based on Estimated Landing Times (ELDT) calculated from a variety of data sources. When CDM was implemented, business rules were put in place to prioritize certain data sources above another based on quality and accuracy. Nowadays, the quality and accuracy of these sources are thought to be different. Reviewing the current business rules is done by analyzing the quality and accuracy of the data sources, and how flight characteristics or procedures can influence the accuracy of the ELDT.

Graduated: August 2020

Max (MSc) – Aircraft noise model validation using noise measurement feedback

One of the current factors limiting the growth of the aviation industry in the Netherlands is the relationship between the aviation sector and local communities around airports. Aircraft noise production is one of the main causes of nuisance in residential areas reported by RIVM. It is therefore, for the aviation industry as a whole, of great importance to gain a better understanding of the methodology of aircraft noise modelling and make improvements on this modelling process if deficiencies in the current model are detected. The validation of the aircraft noise model, using noise measurements taken around the airport, is crucial for the scientific foundation of the model. This scientific foundation is expected to increase the transparency in how noise calculations are performed, which increases community trust in the aviation industry as a whole.

Graduated: July 2020

Ashley Scheenloop (BSc) – Impact of the fleet mix on the outbound capacity at Schiphol Airport

With the future growth in amount of flight movements in the aviation sector, efficient use of the airport resources are getting more and more important. In 2019 it was seen that the declared runway capacity at Schiphol airport is not reached during the outbound peaks. Previous research showed that the aircraft type (Wake turbulence category) influences the runway capacity. With the use the A-CDM principle, the outbound phase at Schiphol airport is analysed. This way the time spent, between the time references (A-CDM Milestones), for each Wake turbulence category is analysed and compared. This will provide an insight on the behaviour of these aircraft types, and indicates a possible significant difference/bottleneck. Besides the active runway combinations are analysed during these outbound peaks.

Graduated: July 2020

Marc Out (BSc) – Reducing the fluctuations on the outbound planning at Amsterdam Airport Schiphol

At Amsterdam Airport Schiphol, the outbound planning is created by the Collaborative Pre-Departure Sequence Planner (CPDSP). Currently, this outbound planning is fluctuating because of frequent updates of the Target Off-Blocks Time (TOBT). Having a dynamical outbound planning could create in a loss of valuable outbound capacity and increasing the risks in regulated flights by EUROCONTROL. To reduce the occurrence of frequent TOBT updates, different business rules have been analyzed for the auto-TOBT update mechanism. This mechanism updates the Target Off-Blocks Time automatically once the inbound flight has an assigned landing runway until the moment the aircraft is in-blocks or the Main Ground Handler updated the TOBT manually. The analyzed business rules had different characteristics related to the frequency of TOBT updates and the accuracy of this target time. Those two main characteristics were required to analyze to be able to have an overview which business rule creates less updates but having the same quality as in the current situation.

Graduated: July 2020

Thijs Scheffers (BSc) – Improving the outbound planning process at Amsterdam Airport Schiphol

To improve the outbound planning process of Schiphol Airport, the frequency, availability and accuracy of Estimated Landing Time (ELDT) data has been investigated. Special attention is placed on the information sharing and the calculation of the ELDT, that is calculated by Amsterdam Advanced Air traffic control system (AAA). In addition, the search for new and accurate data sources to estimate the landing time is a continuous effort. As of November, 2018, a new arrival management (AMAN) system is in use at LVNL, called Advanced Schiphol Arrival Planner (ASAP), which replaces the old arrival system, called Inbound Planning (IBP). The new AMAN has implemented different internal characteristics and processes, such as a new trajectory predictor and planning algorithm. Therefore, the new AMAN could potentially provide more accurate arrival time predictions. Both systems are compared to identify their performance.

Graduated: April 2020

Matthijs Ottenhoff (MSc) – Wind and Trajectory Uncertainty in a 4D Trajectory Management Interface

With air traffic numbers increasing, a shift in the Air Traffic Management system towards 4D flight plans, where an aircraft trajectory is pre-planned in both time and space, is foreseen. When these pre-planned trajectories are subsequently executed, unforeseen airspace perturbations, such as weather, sequencing and changing airspace constraints, will inevitably require small changes in the trajectories to be made by the air traffic controller. This perturbation management control task will consist of ensuring a safe airspace while adhering to the strict time constraints imposed by the 4D flight plan. In collaboration with LVNL, a decision support interface was designed and evaluated with the aim of visualizing possible conflict resolutions in the 4D domain. A special focus was put on the integration of wind and trajectory uncertainty information into the interface.

Graduated: March 2020

Eline Bakker (MSc) – Design and Evaluation of a Visual Interface for an En-Route Air Traffic Control Merging Task

In the past decades, the air traffic growth has resulted in increasingly complex situations involving more aircraft simultaneously. In order to guarantee safety is maintained within the increasingly crowded airspace, new solutions are expected. In collaboration with the LVNL, an Inbound Traffic Support System interface was developed. The goal of the interface is to visualize the possible solutions of an area controller’s task of merging aircraft towards a restricted waypoint in the current work domain, such that the impact of decisions made can be foreseen.  By showing the affordances of the work domain, the display keeps the air traffic controller as the active decision maker rather than issuing advisories.

Graduated: October 2019 

Femke Mollema (BSc) – Creating more capacity at Amsterdam Airport Schiphol by reducing planning inefficiencies amongst KLM, LVNL and AAS

As of today, the aviation parties at Amsterdam Airport Schiphol are connected to the European network managed by Eurocontrol NMOC (Network Manager Operation Centre) through its local Airport CDM (Collaborative Decision Making) process. Within the Dutch aviation industry, many stakeholders are involved in the air traffic process, of which three of the main stakeholders are KLM, AAS and the LVNL. Each stakeholder can influence a certain part of the air traffic process, for which they create their own planning. Other parts of the air traffic process, over which a stakeholder has no control, are influenced, and planned on, by the remaining stakeholders. Since the air traffic process is a continuous cycle all stakeholders involved carry dependencies on one another, which also influences the planning each stakeholder makes. To succeed both the overall air traffic process and thus the stakeholders’ individual process, a collaboration among stakeholders is required. The goal of this research is to determine which planning inefficiencies may arise as a result of the different points of interests of the stakeholders within the Dutch aviation sector. By determining these inefficiencies, it can be researched how these can be eliminated, which could eventually benefit the capacity problem. For the purpose of this research the focus will primarily be on KLM flights.

Graduated: August 2019

Sybren Kuiper (BSc) – Evaluation of plan stability deviations in the flow at Schiphol airport

Over the last years Schiphol has experienced a growth in aircraft movements and exchange of narrow body aircraft for wide body aircraft. The infrastructure has been unable to change at the same pace increasing the pressure on the ground operations capacity and forcing the growth into the off-peaks moments where free infrastructural capacity was available. By growing in the off peaks a new challenge arose. The unused capacity was of essential value in the system plan stability. It offered flexibility that could be used to recuperate from planning deviations. The situation created, can cause a deviation from the plan to trigger a domino through the day that cannot be halted because there is no recuperation space. To stop this effect, it is essential to perform research into the current situation of the plan stability, and the exact causes that start or continue the domino effect. To do this the research will answer the following research question: “What are the opportunities for Amsterdam Airport Schiphol and the other KDC stakeholders to improve the airside ground operational plan stability of the airport?”

Graduated: August 2019

Kyara Metz (BSc) – Evaluation of peak hour capacity at Schiphol and similar airports to determine common capacity management practices

According to EUROCONTROL, Schiphol has the most significant contribution on global ATFM airport delays of all the European Airports; weather and airport capacity were targeted as primary cause of delays. Therefore, this research investigates the potential uses of holding buffers of inbound flows at Amsterdam Schiphol Airport (AAS) during peak hour of operations to absorb delays; special attention is placed on analysing the current methods employed by Schiphol and other Airports uses holding buffer not as a reactive resource for ATCs but a everyday use tool to maximize throughput on runway.

Both quantitative and qualitative research has been used to investigate which operational possibilities LVNL has to buffer inbound traffic in the Dutch airspace and to what extent these buffers can be used in managing the operational inbound peak capacity. To determine the current linear buffer capacity, 20,000 flights from July 2018 were analysed.

Graduated: August 2019

Davey Hooijmeijer (MSc) – Schiphol noise analysis for fixed arrival routings 

In this thesis research, dutch aircraft noise model (NRM) calculations are compared to measurements to analyse the aircraft classification used in the model. To do so, a new implementation of the model has been set up to calculate with LVNL trackdata and NOMOS measurement data. First, the classification approach is analysed as prescribed, which shows clustering of aircraft types when compared to measurements. After, the theoretical input data as prescribed for the model is assessed and replaced by real data for each type specific. This leads to improvements of the model calculations when compared to measurements and shows that aircraft-specific flight-information would improve the model significantly. Concluding, it is shown that aircraft noise models strongly rely on the quality of the input data. Current input data shows certain mismatches with respect to reality, resulting in differences between calculations and measurements. However, the calculations can give valuable insights in the effect of operations on the overall noise exposure.

Graduated: July 2019

Anouk Hollebeek (BSc) – Evaluation of AMAN implementation to establish improvements in the arrival efficiency

A new Arrival Management system, called Advanced Schiphol Arrival Planner (ASAP), was implemented in 2018 to regulate the arrival traffic flows at Amsterdam Schiphol Airport (AAS). ASAP aims to be an assisting support tool for the Approach Planner (APLN)  to monitor and safety merge inbound traffic flows in the Dutch Terminal Control Area (TMA). To validate the implementation of ASAP diverse analysis have been run. This work describes some recent insights and findings regarding the performance and interaction between users (ATCs) and ASAP. Particular attention is placed to establish the moment and type of interaction between the different users. The performance of the tool was evaluated using four main performance indicators; Expected Approach Time (EAT) adherence, slot adherence, holding ratio, influence of APLN.

Graduated: July 2019

Flore Wassenberg (BSc) – D-1 process impact evaluation

In 2018, it was started as part of the development of the capacity management function was the D-1 project. The D-1 project intends to provide an operational and capacity plan before the day of operation. Within the D-1 project team there is a need to validate the quality of the predicted traffic demand, because the prediction generated was not quantitatively evaluated afterward. To explore the reliability and usability of the traffic demand prediction at D-1, a bachelor thesis research has been performed. This research has been done by means of comparing the D-1 traffic demand prediction with the demand on the day of operation. The last submitted flight plans at D0 have been compared to the data predicted on D-1. The sample used contains data that was generated during a period of three months of the D-1 project trial. The research concludes that the traffic demand prediction is for parts not accurate enough to support the D-1 decision making process.

Graduated: July 2019

Casper Moll (BSc) – Capacity analysis of airport slot planning and air traffic demand

According to Eurocontrol,  in 2017 Schiphol Airport was the airport with the biggest inbound ATFM delay of all major airports in Europe. One of the reasons that could cause the inbound ATFM delay is the so called ‘bunching’ effect at the border of the Dutch airspace. The objective of this research is to determine if the encountered planned bunches at -3-hour planning phase has an impact on the airport slot planning. This research focusses on the airport slot declaration and the planned demand based on the last filed flight plans, covering a period from the 25th of October 2017 till the 27th of October 2018. The analysis  contains 254,000 arriving flights in both winter and summer season. The analysis determines to which extent the bunching occurs in the airport slot declaration, and at the border of the Dutch airspace. The results reveal that bunching are present in the pre-planning phase within the airport slot declaration and is caused by the skewness within the airport slot-brackets. The analyses render similar patterns in which overdemand occurs within the time-brackets. The subsequent relationship between the airport slot planning and air traffic demand is around 48%, within the assumptions and limitations of the research. This means that 48% of the flights which are planned in a period with overdemand within the airport slot allocation, also tend to arrive in a period with overdemand at the border of the the Dutch airspace.

Graduated: June 2019

Marc Riebeek (BSc) – Comparison of airport slots and schedule & flight planning

Amsterdam Airport Schiphol is the airport with the most airport Air Traffic Flow Management (ATFM) delay in Europe in 2017. One of the causes of the ATFM delay is that airlines do not adhere to their allocated airport slots. With providing insights into deviation between flight schedules or flight plan and airport slot, causes of deviating to the airport slot are identified. This research is done by means of analysing the deviations to identify the characteristics of the deviations. In addition, interviews with airlines and a ground handler and literature about possible causes are used to provide insights. The main findings are that ~ 3.3% of the flight schedules deviate from the airport slot. The deviation between flight plan and airport slot is around 67% of arriving flights. This deviation of flight plans means that the estimated in block time (EIBT), deviates more than 5 minutes from the airport slot. Both in absolute amount and relative percentage, general aviation and cargo airlines are the business models that cause the most deviation between flight schedule and airport slot. An agreement between the general aviation ground handlers and the typical business of cargo are the main reasons for the deviation. The full-service carriers and low-cost carriers cause in absolute number, the most deviation between the EIBT based on flight plan and airport slots. If the EIBT, based on the flight plan, is earlier than the airport slot, more than 90% of these arrivals are planned earlier because of schedule buffers.

Graduated: June 2019

Mats Dirkzwager (MSc) – Design and Evaluation of a Visual Interface for Separation Support in Time-Based Approach Air Traffic Control

On final approach, an Approach (APP) Air Traffic Controller (ATCo) is responsible for keeping sufficient separation between aircraft lining up on the ILS. The current industry standard is to separate these aircraft with a minimum distance, called Distance-Based Separation or DBS. European regulation requires all European airports to implement separation based on time (TBS) before 2024. Due to this implementation, effectively changing the APP ATC task from a geometrical to a time-based problem, and because of further complications such as the European Re-categorisation of aircraft types, experts fear that the theoretical gains attainable by using TBS will not be fully realised. In this research, a display tool concept to aid APP ATCos in realising the full potential of TBS, the Ideal Turn-In Point (ITIP) display is designed and evaluated with respect to the current state of the art. The ITIP display assists controllers in selecting optimal approach strategies starting from the moment aircraft enter the Terminal Control Area. The display aims to assist the operator by showing the possibilities and restrictions in the system rather than giving (restricting) advisories. In an initial proof-of-concept experiment, comparing the ITIP display to the current industry state of the art display, promising results were found; the ITIP display was shown to maintain safety and increase efficiency, whilst maintaining controller workload. The current industry state of the art display is a tool designed by the National Air Traffic Services, currently operational at London Heathrow Airport.

Graduated: June 2019

Marc Voogt (BSc) – Operational benefits since the connection of Amsterdam Airport Schiphol with the Network Manager.

Key to enabling growth at Schiphol without compromising on safety, efficiency and the environment is to increase the predictability of traffic flows. Procedures put in place by Collaborative Decision Making (CDM) support predictable traffic flows not only at Schiphol but also in the surrounding airspace of Central Europe…Research is carried out into the effectiveness of CDM since the data -connection and the impact on operational partners at Schiphol and in the EUROCONTROL  network. The data-connection is identified to have improved the accuracy of take-off time predictions at Schiphol considerably with an average monthly increase of 6% of all departing movements regarded as having a predictable take-off time. Towards the network this take-off time predictability has increased significantly. In relation to similar major-hub airports, the increased take-off time predictability and the exchange of more accurate operational planning data between Schiphol and the NMOC are identified to have contributed to the significantly high compliance to imposed take-off times (93% of all departing movements) supporting stable Network Management. Although significant increases in delay throughout the EUROCONTROL network are increasingly affecting a stable planning of aircraft parking stands at Schiphol, indications for a reduction in stand-delay and other KPIs related to improved flow-efficiency at the airport are identified.

Graduated: April 2019

Tessa Rietema (BSc) – Capacity requirements analysis of civil air traffic in military controlled airspace

The determination of the capacity of the Lelystad Terminal Manoeuvring Area (TMA) is complex and brings different challenges. The opening of Lelystad airport for civil air traffic is the motivation to perform research into the capacity of the Lelystad TMA…The aim of this research is to help CLSK to determine the capacity factors and the capacity of the Lelystad TMA…By means of interviews and expert sessions with operational experts of CLSK, data is created to use during the research. With the data, the volume and capacity of the TMA is calculated. After this, a bottleneck analysis is conducted for the capacity of the handling process. The bottleneck in the handling process is the airport with its aircraft stands. After this, the TMA is the limiting capacity compared with the runway. Additionally, the annual maximum flight movements of 4,000 and 10,000 is feasible with the structure of the TMA. When the airport becomes operational for commercial traffic, the established capacity must be validated

Graduated: February 2019

Bas Broekstra (BSc) – Impact of Special Events on Airspace

Large-scale (e.g. Tour de France, Nuclear Security Summit, etc) or other special events can mean a temporary  increase in (concentrated) traffic in the airspace. These interruptions of normal operations can have impact on the airspace capacity and air traffic controller workload. The objectives of the research is to analyse and evaluate the impact of past events, to provide insight in the capacity impact of an event. To do so, operational requirements of different events are evaluated and analysed, with the aim to provide possible improvements to be better prepared for future events. Improvement could include procedural recommendations to manage special events in the airspace, to ensure that capacity is managed in efficient ways in the future. How do current procedures, to determine the impact of special events on airspace capacity, justify the impact on operations to stakeholders in Dutch airspace?

Graduated: July 2018

Marc Eijkens (BSc) – Analysis of Vertical Flight Trajectory Efficiency

The objective of this research is to analyse the effects of the current hand-over conditions on both horizontal and vertical flight trajectory efficiency. This analysis provides insight into the significance of how the current hand-over conditions affect operational efficiency. It will present an understanding of the impact on air traffic controller (ATCo) workload when this additional coordination is carried out. Besides analysing the impact on operational efficiency and ATCo workload, the research will provide possible solutions to the problem at hand. Solutions could range from procedural changes to technical innovations which will not negatively impact/increase controller workload.

Graduated: July 2018

Gijs Peters (BSc) – Impact Analysis on the Airside Infrastructure at Schiphol

The airside infrastructure layout of AAS is very complicated, and bottlenecks are easily formed. With this growing amount of movements, bottlenecks will occur more often and influence the capacity. Every stakeholder has its own perspective on the current problems and cooperation is difficult to achieve. The research gives an overview of the current bottlenecks at the runways, taxiways and gate/buffer areas to create more awareness of the seriousness of the problem. More awareness will stimulate a better cooperation between the main stakeholders of AAS’ airside infrastructure. Also, a list of possible solutions is created.

Graduated: July 2018

Martijn Ringelberg (BSc) – Airline Strategies’ Impact on Gate Occupancy

How do airline characteristics, ranging from business model differences to variation in actual procedures, affect AAS airside capacity? Schiphol airport is reaching its limit based on the cap of 500.000 movements per year. For reaching this amount of movements a lot of capacity constraints have already been tackled, not all of them however. There are numerous airlines operating at Schiphol, and all of these airlines have various differences and equalities ranging from differences between business models to differences between pilots. The fleet size or structure of an airline for example can impact the maximum number of movements per hour of a runway as bigger aircraft need to have more separation than smaller aircraft. Another issue is the communication between airlines and airport. This may lead to congestion as the airport wouldn’t be able to plan the gate capacity well in advance. When the impacts of airline strategies are known in more detail, AAS and LVNL would be able to plan accordingly to have less capacity congestion.

Graduated: July 2018

Roel Wouters (BSc) – Impact of Local A-CDM on the Operational Efficiency at Mainport Schiphol

AAS is at the final stage of having Airport- collaborative decision making (A-CDM) completely implemented. The last step is to connect the network manager and then AAS will be a CDM airport. The network manager is currently not yet connected and, therefore, not taken into account in this study since there is not any data available yet. Local A-CDM is currently implemented at AAS which includes the four other main stakeholders (Airport operator, Aircraft operator, ATC and ground handlers). Local A-CDM should improve the stakeholders’ operational efficiency by improving the predictability and decision making.  It is likely that A-CDM has been beneficial for the operation of each involved stakeholder at AAS. However, for all stakeholders it is still uncertain how much the operational efficiency has improved thanks to the implementation of local A-CDM. The aim of this study is researching how local A-CDM has exactly improved the operation’s efficiency for each involved A-CDM stakeholder at Mainport Schiphol until now, and what the exact benefits are.

Graduated: July 2018

Huib de Jong (BSc) – How can Schiphol transition to use of APOC in an effective way?

ATC controllers are respected for their high-performance jobs, training is consistent and on high quality level, still the individual controller has the opportunity to guide air traffic in the most efficient way for that moment. An analysis of ATC decision making (taxiway, gates, runway usage, approach and take-off routing), finding deviations and variations in the operation, should determine the current way of working and should form the basis to work towards APOC. In APOC, a key difference between the current situation is the way of information sharing and availability, this difference with the current situation should be analyzed, providing the insight how to transition towards the use of APOC. The results must provide how the current decision-making process impacts capacity and to what extent can these deviations and variations be reduced when APOC is used. Furthermore, what are benefits and what are the requirements to transition to this future situation. In addition, also maintaining sufficient flexibility in the operations after the decisions have been made.

Graduated: March 2018

Remsey Kanis (BSc) – Analyses of deviations and variations in the ground operations due to runway changes

Schiphol has the most runways in Europe with respect to major hub airports, this does not automatically translate to the highest ATMs. During the day runway use is changed, primarily because of the noise restrictions surrounding Schiphol. An analysis of the impact on the capacity on the ground and in air, is needed to determine, how this already complex change of runways also increases the complexity in other parts of the system. Included in the analysis the effect on TATs can be determined possibly through A-CDM data, also information from the ORS (Omgevingsraad Schiphol) must be considered as input. The results must provide an effect analysis on specific parts of the system and the reasoning, the related stakeholders need to be covered also the cost and benefits in operational sense need to be addressed.

Graduated: March 2018

Joep Boekhout (BSc) – Analysis of the effectiveness of the limitation/regulations in controlling airspace towards and from Schiphol

Air traffic controllers find the most efficient way to align aircraft towards the runway, maintaining separation requirements, trying to prevent delays, choosing the most fuel-efficient routes for airlines from and to the airport. Although in some cases regulations in the airspace are deemed necessary to cope with an increase in demand, on top of that pilots (airlines) tend to defeat the system by asking for directs (deviations), instead of following the rest. In addition, relaxing some airspace constraints did not have the effect of a higher utilisation of the airspace. The analysis should provide insight in the effectiveness of limitation/regulations used in the airspace. Possible input can be an aircraft priority study (KLM), that provides the airline with information which aircraft to speed up or slow down. The results of the research must provide air traffic controller with the impact of certain regulations and also airspace users with the insight on how their decisions impact the whole system. Included should be at least a list of the most used regulations with their impact/effectiveness and deviations by users including their impact as well. The customer wants to get insight in the current effectiveness of Network Manager regulations, and in particular the effect of airline/pilot behaviour on the effectiveness of regulations.

Graduated: March 2018

Eneko Rodríguez (MSc) – Investigating the effects of Flexible Use of Airspace availability and plannability on fuel efficiency

All military airspace in the Amsterdam Flight Information Region (FIR) falls under the concept of Flexible Use of Airspace (FUA), which no longer considers airspace as purely ‘civil’ or ‘military’ but rather as a continuum to be allocated temporarily according to user requirements. The complexity of FUA lies in the challenge to harmonize the airspace usage according to these requirements, which largely contradict one another. On the one hand, the military user benefits from using the airspace flexibly, as the effectiveness of their missions and exercises depend on the availability of weather and equipment conditions. On the other hand, the civil users benefit from a high plannability to efficiently execute their operations. By modeling the fuel consumption of civil traffic, the effects of availability and plannability of the FUA in Amsterdam FIR can be computed. While FUA availability determines the route followed by a flight, FUA plannability determines how early the true trajectory is known. Announcing the FUA usage earlier results in avoiding to carry a surplus fuel, which increases the weight and thus fuel burnt of the aircraft. By understanding these effects, new guidelines of FUA usage and plannability may be proposed in the context of the ongoing Dutch Airspace Redesign Programme.

Graduated: August 2022

Bart Rozendaal (MSc) – A neural network approach in optimising
airport strategy with trajectory prediction

As the airspace is getting increasingly crowded worldwide, the capacity management of airports is more important than ever. To avoid unnecessary and costly delays, it is crucial for airports to have well timed strategies and reliable arrival predictions. To achieve this, airports need accurate long-term trajectory predictions such that arrival times can be estimated with high precision. Countless factors such as weather conditions, restricted fly areas and air traffic control clearances cause route uncertainties, making it difficult to predict long-term trajectories accurately. In this thesis, a bidirectional LSTM recurrent neural network is proposed to solve a sequence-to-sequence learning problem and predict the most likely route flown by the aircraft before take off. The network is trained on historical flight plans only, making it easy to implement. The data exists of incoming flights on Schiphol international airport within Europe. Different Hyperparameters are tested to improve performance of the network.

Graduated: July 2022

Thomas Vermeulen (MSc) – Evaluation and assessment of the performance of the KNMI Schiphol Kansverwachting (SKV) for Mainport Schiphol with respect to wind direction and wind gusts

Accurate weather forecasts are crucial information to regulate the operations at Schiphol Airport. Sudden changes in weather conditions need to be communicated in a fast and efficient way to maintain the safety and efficiency for flight operations. KNMI provides a probabilistic weather forecast, called the Schiphol Kansverwachting (SKV), which is produced using output of numerical weather prediction models in combination with the latest observations and several statistical post-processing tools. In particular information on the wind direction and the wind gusts is highly important to support air traffic control. Relatively large errors could lead to restrictions which were in the end not needed or it could lead to restrictions which were issued too late. This research will evaluate the performance of the SKV of wind direction and wind gusts for three different weather models: HIRLAM, HARMONIE and ECMWF. Quantitative information on the forecasting errors will be identified, but also suggestions for possible improvements on the weather forecasts will be part of the result of this study.

Graduated: July 2022

Wesley Vork (BSc) – Develop sequential steps towards a Multi Airport System (MAS)

Dutch airports have grown significantly over the years. This growth is occurring almost autonomously. No mechanisms have been put in place to strategically balance this growth between Dutch airports, routes, or airspace. Without major reforms, the maximum capacity of the airspace will soon be reached. The relationship between EHLE, EHEH, EHRD and EHAM is under scrutiny. With autonomous growth and without mitigating measures, this will lead to the first airspace bottlenecks in 2023 and contiguous bottlenecks in 2035. By examining how air traffic can be better handled through joint air traffic management, the capacity bottlenecks can be addressed. By conducting a thorough research on the MAS, it will become clear what problem the MAS solves and how this system can be used to solve the capacity bottlenecks.

Graduated: July 2022

Max Aalberse (MSc) – Optimizing the distribution of aircraft over the IAF

Around Schiphol and many other airports the amount of movements allowed is constrained due to the considerable noise pollution from aircraft. For a large part the noise pollution is created by arriving aircraft that are in between the IAF and the RWY. During this period the aircraft are in so called transition. These transition routes are usually already optimized to reduce the noise disturbance to surrounding residents, but due to the positioning of the runways this is not always possible. A different distribution of the aircraft over the IAF could result in less noise disturbance for surrounding residents, but would also increase flight times and fuel usage and therefore an increase in other emissions such as CO₂. The goal of this research is to create a parameterized model that optimally distributes the aircraft over the IAF based on a quantitative trade-off between noise disturbance and CO₂ emissions. Resulting in a model that is potentially able to reduce noise disturbance around airports while keeping the increase in environmental impact at a minimum.

Graduated: June 2022

Edzer Oosterhof (MSc) – Effect of Trajectory Prediction Uncertainty on Debunching of Inbound Air Traffic

With the current growth in air traffic and the resulting developments in terms of environmental issues and noise abatement, the pressure on the Area Control Center (ACC) is growing. On the one hand the Terminal Control Area (TMA) requires arriving traffic to be handed over accurately sequenced and merged, and on the other hand the ACC tries to minimize the miles flown in its sector. At the tactical level, there are Air Traffic Flow Management (ATFM) measures in place for traffic within Europe. However, no such tactical measures exist for traffic from the North Atlantic Tracks, increasing the probability that bunching occurs in the ACC during peak loads. By tactically predicting bunching in the sector and at the Initial Approach Fixes, a concept for debunching should be devised that focusses on airborne delay consumption and sequencing of traffic in the Upper control Areas (UTA) before it enters the Control Area (ACC), decreasing the pressure on the ACC.

Graduated: March 2022

Rebekka van der Grift (MSc) – Aircraft Noise Model Improvement by Calibration of Noise-Power-Distance Values Using Acoustic Measurements

The impact of the aircraft industry on the environment becomes more evident every day. Especially for local communities around the airport, the noise nuisance is an important factor which puts a strain on the capacity of Schiphol mainport. This capacity is based on the noise levels around airports, which are calculated with noise models based of key input parameters. The accuracy of these models is thus of great importance for the Schiphol mainport and the local communities. This research aims to develop a dynamic noise model based on real world aircraft noise measurements taken by NOMOS. The measurements will be used to calibrate certain input parameters to minimise any differences between model and measurements. This method helps to keep the model up to date and validated. Using measurements instead of standard input parameters is expected to increase the accuracy of the model, but also increase the trust of local communities in noise modelling.

Graduated: January 2022

Stephanie Wiechers (MSc) – Design and Evaluation of a Support Tool for Planning Adherence While Holding Inbound Air Traffic

As Schiphol is one of the busiest airport in the world, with tight flight schedules and urban areas that lie under arrival routes, adherence to the time planning is very important. When extreme weather conditions cause delays over the entire arriving fleet, holding stacks are installed at the three Initial Approach Fixes (IAFs) around Schiphol. In the current operational environment, little support is offered to the holding stack controller (ACC) to gain an overview of the effects of speed and wind on the turn times and difference between inbound and outbound leg velocity. With increased support, the controller will be able to make decisions based on representative information and with that, deliver inbound aircraft to Approach (APP). The (expected) resulting increased EAT adherence should lead to more orderly traffic in the TMA, improving capacity and workload.

Graduated: December 2021

Soraya van Beek (MSc) – Improving probabilities of poor visibility and ceiling

In order to optimize the current Schiphol operations, an accurate weather forecast is of great importance. The Royal Netherlands Meteorological Institute (KNMI) provides a probabilistic weather forecast for Low Visibility Procedures (LVPs) to Schiphol, which is computed using deterministic weather models. If these LVPs occur due to low visibility or low ceiling, adjusted capacity and flow restriction are needed within airport operations. Inaccurate forecasting can lead to last-minute restrictions or restrictions when not needed. This research will assess the performance of the probabilistic forecast of visibility and ceiling at Schiphol airport. This will be done for the performance of three different weather models: HIRLAM, HARMONIE and ECMWF. Causes for inaccurate forecasting will be identified and suggestions for improvement of the probabilistic weather forecast will be the end result of this research.

Graduated: October 2021

Gijs Bekkers (BSc) – Improving Operational Plan Preparation for Amsterdam Airport Schiphol

Stakeholder preparation for future operation is currently carried out mostly individually, with limited and mostly untimely access to relevant information. Through identifying and mapping plan development for each involved actor, it is possible to find commonalities and moments of information exchange. Data that could be of relevance for others is often kept private, due to lack of insight in handling by others and lack of knowledge on collective benefits of information-sharing. Using feedback from the Airport’s Operation Centre (APOC) on their Airport Operations Plan (AOP), and from LVNL on their OPS plan, together with expert recommendations, poses improvements for desired information sharing within stakeholders. Optimizing the plan-establishment processes and collectively arranging operational preparation yields benefits for all involved stakeholders. To finally ensure proper execution, data-exchange and arrangements should be constantly monitored using chosen performance indicators.

Graduated: June 2021

Janjaap Wijnker (BSc) – Evaluating the accuracy of information provided by the (D-1) OPS plan

In early 2020 LVNL implemented the OPS plan with the objective to improve the alignment of traffic demand with available capacity. This can be achieved by improving the predictability of the operations and make this transparent and accessible for the stake-holders. Every day the PRE-TACT unit develops an OPS plan for the following operational day. The plan contains two types of information, external factors that might impact the capacity, and recommendations for the most optimal operations. The recommendations are based on the external factors, for example the predicted traffic demand and weather forecast. These two factors contribute to the configuration of runways, and the runway selection determines the required capacity. In order to for LVNL to improve possible deficiencies of the OPS plan, the aim of this research study is to evaluate the accuracy and precision of the predicted traffic demand. The analysis focusses on the difference between predicted and actual traffic demand on a 20 minute resolution. In addition, the implications of factors contributing to the proposed runway configuration will be assessed since the use of different runways could have a significant impact on the capacity.

Graduated: June 2021

Christophe Vakaet (MSc) – Taxi Time Prediction with Classical and Auto Machine Learning at Schiphol Airport

Ground control uses the Departure Sequence Planner (DSP) to optimally plan departures within the operational constraints. The DSP uses an estimated Variable Taxi Time (VTT) to calculate an aircraft’s Target Take-Off Time (TTOT). If the VTT is underestimated flights will not make the determined TTOT, while an overestimation requires the air traffic controller to tactically hold an aircraft. These consequences result in delays, capacity losses, additional workload, and uncertainty. This uncertainty inhibits further operational optimizations. The VTT is currently predicted based on the average taxi times for different gate-runway combinations, wake turbulence categories, deicing procedure, and simplified runway configuration. The goal of this project is to improve VTT predictions by employing machine learning techniques and additional data sources such as traffic density, weather, aircraft type, and more.

Graduated: June 2021

Mathijs Post (MSc) – Air Traffic Flow Management for Amsterdam Airport Schiphol

Air Traffic Flow Management is a measure to optimize the flow of traffic in the European air transportation system. Flights are planned such that these can be operated with as little delay as possible. However, on the day of operation many changes can still happen. Amsterdam Airport Schiphol is the biggest contributor to Airport ATFM Delay in Europe, meaning many flights are delayed because of congestion or other airport related reasons at Schiphol. Besides Airport ATFM Delay, the arrival punctuality of flights at Schiphol can be improved. More insights into the causes and interactions of operational parameters is necessary to understand the main contributors for Airport ATFM Delay and arrival delay. A Bayesian Network is proposed, which is a Probabilistic Graph Model that can find interactions between variables and can identify the operational conditions leading to Airport ATFM Delay and arrival delay.

Graduated: June 2021

Bart Bouwels (MSc) – Air Traffic Management Concept for Off-Idle Continuous Descent Operations at Schiphol

Due to the continued growth of the aviation industry, emission and noise production are at an all-time high. In order to reduce this, conventional approaches could be replaced by continuous descent approaches (CDA). These eliminate all level segments, greatly reducing the average thrust setting, resulting in large reductions in noise and emission production. The problem with almost all CDA procedures is that it makes it much more difficult to predict the future position of an aircraft since it flies its own optimal descent profile, with zero thrust. This results in a need for more separation, greatly reducing the airport capacity. This can largely be solved by using a fixed, constant descent angle for all aircraft. Assessing the robustness of such a concept for a high capacity airport is therefore an important stepping stone towards actual implementation.

Graduated: May 2021

Brian Verhoeven (MSc) – Improving the predictability of Aircraft Induced Lightning (AIL) for Mainport Schiphol

Lightning strikes to aircraft are not uncommon in aviation. Although they are not dangerous anymore, they can still result in damages to the aircraft and delay airline operations. Passengers can get scared from the lightning strike as well. Especially in the region around Amsterdam Schiphol Airport, AIL can occur during fall and winter as well. Estimations are that 90% of the lightning strikes are a result of the aircraft triggering a lightning strike, rather than being accidentally struck. In order to prevent as many strikes as possible, it is thus key to understand this process. Therefore, this research aimed to gain a as complete as possible understanding of the process of AIL and use this knowledge to supply new information about AIL to pilots, as AIL is not included in most standard pilot trainings. This can allow pilots to become more aware of AIL and prevent more lightning strikes and the corresponding inconveniences from occuring.

Finished internship: January 2021

Jeanette Derks (MSc) – Coordinated Arrival and Departure Management for Dependent Runway Operations

The foreseen increase in air traffic movements in combination with eased separation minima between aircraft, redefined by the International Civil Aviation Organization (ICAO) in 2015, is expected to emphasize current runway dependencies at airports even further. As the number of aircraft in vicinity of an airport will increase, conflicting flight paths between arriving aircraft and departing aircraft will become a bigger safety hazard and will affect the efficiency of both the arrival and departure traffic flow. Airports that rely on dependent runways in their daily operation await serious congestion problems if no coordination between arrival and departure management will be initiated soon. Therefore, this research aimed to increase runway configuration capacity at airports that experience interference between arrival and departure capacity due to the use of dependent arrival and departure runways by developing and exploring multiple concepts for a coordination mechanism between Arrival and Departure Management.

Graduated: November 2020

Robin Vervaat (MSc) – Priority-based flight scheduling in the tactical phase

Years of growth in air travel have meant that, as usage is nearing current capacity, delays are becoming virtually inevitable for air carriers operating in our airspace. Flight delays have a significant impact on airport and airline operations, as well as their cost. As such, tactical planning of the flights has become increasingly important, especially for a hub-operator with many connecting passengers. In collaboration with LVNL, KLM and Amsterdam Airport Schiphol, a novel model is being investigated tasked with the Arrival Sequencing and Scheduling of flights considering (airline) priority criteria. Smarter use is to be made of the available infrastructure in order to increase capacity and decrease delay (costs), however, fairness and equality between stakeholders will still need to be upheld.

Graduated: September 2020

Bas Timmer (BSc) – Analysing inbound sources of information to improve the predictability and accuracy of the landing times

With the growing aviation industry in Europe, efficient use of the inbound capacity becomes even more important. One of the determining factors in capacity is the ability of accurately predict the landing time of aircraft. LVNL systems AAA and ASAP generate their inbound sequence planning based on Estimated Landing Times (ELDT) calculated from a variety of data sources. When CDM was implemented, business rules were put in place to prioritize certain data sources above another based on quality and accuracy. Nowadays, the quality and accuracy of these sources are thought to be different. Reviewing the current business rules is done by analyzing the quality and accuracy of the data sources, and how flight characteristics or procedures can influence the accuracy of the ELDT.

Graduated: August 2020

Max (MSc) – Aircraft noise model validation using noise measurement feedback

One of the current factors limiting the growth of the aviation industry in the Netherlands is the relationship between the aviation sector and local communities around airports. Aircraft noise production is one of the main causes of nuisance in residential areas reported by RIVM. It is therefore, for the aviation industry as a whole, of great importance to gain a better understanding of the methodology of aircraft noise modelling and make improvements on this modelling process if deficiencies in the current model are detected. The validation of the aircraft noise model, using noise measurements taken around the airport, is crucial for the scientific foundation of the model. This scientific foundation is expected to increase the transparency in how noise calculations are performed, which increases community trust in the aviation industry as a whole.

Graduated: July 2020

Ashley Scheenloop (BSc) – Impact of the fleet mix on the outbound capacity at Schiphol Airport

With the future growth in amount of flight movements in the aviation sector, efficient use of the airport resources are getting more and more important. In 2019 it was seen that the declared runway capacity at Schiphol airport is not reached during the outbound peaks. Previous research showed that the aircraft type (Wake turbulence category) influences the runway capacity. With the use the A-CDM principle, the outbound phase at Schiphol airport is analysed. This way the time spent, between the time references (A-CDM Milestones), for each Wake turbulence category is analysed and compared. This will provide an insight on the behaviour of these aircraft types, and indicates a possible significant difference/bottleneck. Besides the active runway combinations are analysed during these outbound peaks.

Graduated: July 2020

Marc Out (BSc) – Reducing the fluctuations on the outbound planning at Amsterdam Airport Schiphol

At Amsterdam Airport Schiphol, the outbound planning is created by the Collaborative Pre-Departure Sequence Planner (CPDSP). Currently, this outbound planning is fluctuating because of frequent updates of the Target Off-Blocks Time (TOBT). Having a dynamical outbound planning could create in a loss of valuable outbound capacity and increasing the risks in regulated flights by EUROCONTROL. To reduce the occurrence of frequent TOBT updates, different business rules have been analyzed for the auto-TOBT update mechanism. This mechanism updates the Target Off-Blocks Time automatically once the inbound flight has an assigned landing runway until the moment the aircraft is in-blocks or the Main Ground Handler updated the TOBT manually. The analyzed business rules had different characteristics related to the frequency of TOBT updates and the accuracy of this target time. Those two main characteristics were required to analyze to be able to have an overview which business rule creates less updates but having the same quality as in the current situation.

Graduated: July 2020

Thijs Scheffers (BSc) – Improving the outbound planning process at Amsterdam Airport Schiphol

To improve the outbound planning process of Schiphol Airport, the frequency, availability and accuracy of Estimated Landing Time (ELDT) data has been investigated. Special attention is placed on the information sharing and the calculation of the ELDT, that is calculated by Amsterdam Advanced Air traffic control system (AAA). In addition, the search for new and accurate data sources to estimate the landing time is a continuous effort. As of November, 2018, a new arrival management (AMAN) system is in use at LVNL, called Advanced Schiphol Arrival Planner (ASAP), which replaces the old arrival system, called Inbound Planning (IBP). The new AMAN has implemented different internal characteristics and processes, such as a new trajectory predictor and planning algorithm. Therefore, the new AMAN could potentially provide more accurate arrival time predictions. Both systems are compared to identify their performance.

Graduated: April 2020

Matthijs Ottenhoff (MSc) – Wind and Trajectory Uncertainty in a 4D Trajectory Management Interface

With air traffic numbers increasing, a shift in the Air Traffic Management system towards 4D flight plans, where an aircraft trajectory is pre-planned in both time and space, is foreseen. When these pre-planned trajectories are subsequently executed, unforeseen airspace perturbations, such as weather, sequencing and changing airspace constraints, will inevitably require small changes in the trajectories to be made by the air traffic controller. This perturbation management control task will consist of ensuring a safe airspace while adhering to the strict time constraints imposed by the 4D flight plan. In collaboration with LVNL, a decision support interface was designed and evaluated with the aim of visualizing possible conflict resolutions in the 4D domain. A special focus was put on the integration of wind and trajectory uncertainty information into the interface.

Graduated: March 2020

Eline Bakker (MSc) – Design and Evaluation of a Visual Interface for an En-Route Air Traffic Control Merging Task

In the past decades, the air traffic growth has resulted in increasingly complex situations involving more aircraft simultaneously. In order to guarantee safety is maintained within the increasingly crowded airspace, new solutions are expected. In collaboration with the LVNL, an Inbound Traffic Support System interface was developed. The goal of the interface is to visualize the possible solutions of an area controller’s task of merging aircraft towards a restricted waypoint in the current work domain, such that the impact of decisions made can be foreseen.  By showing the affordances of the work domain, the display keeps the air traffic controller as the active decision maker rather than issuing advisories.

Graduated: October 2019 

Femke Mollema (BSc) – Creating more capacity at Amsterdam Airport Schiphol by reducing planning inefficiencies amongst KLM, LVNL and AAS

As of today, the aviation parties at Amsterdam Airport Schiphol are connected to the European network managed by Eurocontrol NMOC (Network Manager Operation Centre) through its local Airport CDM (Collaborative Decision Making) process. Within the Dutch aviation industry, many stakeholders are involved in the air traffic process, of which three of the main stakeholders are KLM, AAS and the LVNL. Each stakeholder can influence a certain part of the air traffic process, for which they create their own planning. Other parts of the air traffic process, over which a stakeholder has no control, are influenced, and planned on, by the remaining stakeholders. Since the air traffic process is a continuous cycle all stakeholders involved carry dependencies on one another, which also influences the planning each stakeholder makes. To succeed both the overall air traffic process and thus the stakeholders’ individual process, a collaboration among stakeholders is required. The goal of this research is to determine which planning inefficiencies may arise as a result of the different points of interests of the stakeholders within the Dutch aviation sector. By determining these inefficiencies, it can be researched how these can be eliminated, which could eventually benefit the capacity problem. For the purpose of this research the focus will primarily be on KLM flights.

Graduated: August 2019

Sybren Kuiper (BSc) – Evaluation of plan stability deviations in the flow at Schiphol airport

Over the last years Schiphol has experienced a growth in aircraft movements and exchange of narrow body aircraft for wide body aircraft. The infrastructure has been unable to change at the same pace increasing the pressure on the ground operations capacity and forcing the growth into the off-peaks moments where free infrastructural capacity was available. By growing in the off peaks a new challenge arose. The unused capacity was of essential value in the system plan stability. It offered flexibility that could be used to recuperate from planning deviations. The situation created, can cause a deviation from the plan to trigger a domino through the day that cannot be halted because there is no recuperation space. To stop this effect, it is essential to perform research into the current situation of the plan stability, and the exact causes that start or continue the domino effect. To do this the research will answer the following research question: “What are the opportunities for Amsterdam Airport Schiphol and the other KDC stakeholders to improve the airside ground operational plan stability of the airport?”

Graduated: August 2019

Kyara Metz (BSc) – Evaluation of peak hour capacity at Schiphol and similar airports to determine common capacity management practices

According to EUROCONTROL, Schiphol has the most significant contribution on global ATFM airport delays of all the European Airports; weather and airport capacity were targeted as primary cause of delays. Therefore, this research investigates the potential uses of holding buffers of inbound flows at Amsterdam Schiphol Airport (AAS) during peak hour of operations to absorb delays; special attention is placed on analysing the current methods employed by Schiphol and other Airports uses holding buffer not as a reactive resource for ATCs but a everyday use tool to maximize throughput on runway.

Both quantitative and qualitative research has been used to investigate which operational possibilities LVNL has to buffer inbound traffic in the Dutch airspace and to what extent these buffers can be used in managing the operational inbound peak capacity. To determine the current linear buffer capacity, 20,000 flights from July 2018 were analysed.

Graduated: August 2019

Davey Hooijmeijer (MSc) – Schiphol noise analysis for fixed arrival routings 

In this thesis research, dutch aircraft noise model (NRM) calculations are compared to measurements to analyse the aircraft classification used in the model. To do so, a new implementation of the model has been set up to calculate with LVNL trackdata and NOMOS measurement data. First, the classification approach is analysed as prescribed, which shows clustering of aircraft types when compared to measurements. After, the theoretical input data as prescribed for the model is assessed and replaced by real data for each type specific. This leads to improvements of the model calculations when compared to measurements and shows that aircraft-specific flight-information would improve the model significantly. Concluding, it is shown that aircraft noise models strongly rely on the quality of the input data. Current input data shows certain mismatches with respect to reality, resulting in differences between calculations and measurements. However, the calculations can give valuable insights in the effect of operations on the overall noise exposure.

Graduated: July 2019

Anouk Hollebeek (BSc) – Evaluation of AMAN implementation to establish improvements in the arrival efficiency

A new Arrival Management system, called Advanced Schiphol Arrival Planner (ASAP), was implemented in 2018 to regulate the arrival traffic flows at Amsterdam Schiphol Airport (AAS). ASAP aims to be an assisting support tool for the Approach Planner (APLN)  to monitor and safety merge inbound traffic flows in the Dutch Terminal Control Area (TMA). To validate the implementation of ASAP diverse analysis have been run. This work describes some recent insights and findings regarding the performance and interaction between users (ATCs) and ASAP. Particular attention is placed to establish the moment and type of interaction between the different users. The performance of the tool was evaluated using four main performance indicators; Expected Approach Time (EAT) adherence, slot adherence, holding ratio, influence of APLN.

Graduated: July 2019

Flore Wassenberg (BSc) – D-1 process impact evaluation

In 2018, it was started as part of the development of the capacity management function was the D-1 project. The D-1 project intends to provide an operational and capacity plan before the day of operation. Within the D-1 project team there is a need to validate the quality of the predicted traffic demand, because the prediction generated was not quantitatively evaluated afterward. To explore the reliability and usability of the traffic demand prediction at D-1, a bachelor thesis research has been performed. This research has been done by means of comparing the D-1 traffic demand prediction with the demand on the day of operation. The last submitted flight plans at D0 have been compared to the data predicted on D-1. The sample used contains data that was generated during a period of three months of the D-1 project trial. The research concludes that the traffic demand prediction is for parts not accurate enough to support the D-1 decision making process.

Graduated: July 2019

Casper Moll (BSc) – Capacity analysis of airport slot planning and air traffic demand

According to Eurocontrol,  in 2017 Schiphol Airport was the airport with the biggest inbound ATFM delay of all major airports in Europe. One of the reasons that could cause the inbound ATFM delay is the so called ‘bunching’ effect at the border of the Dutch airspace. The objective of this research is to determine if the encountered planned bunches at -3-hour planning phase has an impact on the airport slot planning. This research focusses on the airport slot declaration and the planned demand based on the last filed flight plans, covering a period from the 25th of October 2017 till the 27th of October 2018. The analysis  contains 254,000 arriving flights in both winter and summer season. The analysis determines to which extent the bunching occurs in the airport slot declaration, and at the border of the Dutch airspace. The results reveal that bunching are present in the pre-planning phase within the airport slot declaration and is caused by the skewness within the airport slot-brackets. The analyses render similar patterns in which overdemand occurs within the time-brackets. The subsequent relationship between the airport slot planning and air traffic demand is around 48%, within the assumptions and limitations of the research. This means that 48% of the flights which are planned in a period with overdemand within the airport slot allocation, also tend to arrive in a period with overdemand at the border of the the Dutch airspace.

Graduated: June 2019

Marc Riebeek (BSc) – Comparison of airport slots and schedule & flight planning

Amsterdam Airport Schiphol is the airport with the most airport Air Traffic Flow Management (ATFM) delay in Europe in 2017. One of the causes of the ATFM delay is that airlines do not adhere to their allocated airport slots. With providing insights into deviation between flight schedules or flight plan and airport slot, causes of deviating to the airport slot are identified. This research is done by means of analysing the deviations to identify the characteristics of the deviations. In addition, interviews with airlines and a ground handler and literature about possible causes are used to provide insights. The main findings are that ~ 3.3% of the flight schedules deviate from the airport slot. The deviation between flight plan and airport slot is around 67% of arriving flights. This deviation of flight plans means that the estimated in block time (EIBT), deviates more than 5 minutes from the airport slot. Both in absolute amount and relative percentage, general aviation and cargo airlines are the business models that cause the most deviation between flight schedule and airport slot. An agreement between the general aviation ground handlers and the typical business of cargo are the main reasons for the deviation. The full-service carriers and low-cost carriers cause in absolute number, the most deviation between the EIBT based on flight plan and airport slots. If the EIBT, based on the flight plan, is earlier than the airport slot, more than 90% of these arrivals are planned earlier because of schedule buffers.

Graduated: June 2019

Mats Dirkzwager (MSc) – Design and Evaluation of a Visual Interface for Separation Support in Time-Based Approach Air Traffic Control

On final approach, an Approach (APP) Air Traffic Controller (ATCo) is responsible for keeping sufficient separation between aircraft lining up on the ILS. The current industry standard is to separate these aircraft with a minimum distance, called Distance-Based Separation or DBS. European regulation requires all European airports to implement separation based on time (TBS) before 2024. Due to this implementation, effectively changing the APP ATC task from a geometrical to a time-based problem, and because of further complications such as the European Re-categorisation of aircraft types, experts fear that the theoretical gains attainable by using TBS will not be fully realised. In this research, a display tool concept to aid APP ATCos in realising the full potential of TBS, the Ideal Turn-In Point (ITIP) display is designed and evaluated with respect to the current state of the art. The ITIP display assists controllers in selecting optimal approach strategies starting from the moment aircraft enter the Terminal Control Area. The display aims to assist the operator by showing the possibilities and restrictions in the system rather than giving (restricting) advisories. In an initial proof-of-concept experiment, comparing the ITIP display to the current industry state of the art display, promising results were found; the ITIP display was shown to maintain safety and increase efficiency, whilst maintaining controller workload. The current industry state of the art display is a tool designed by the National Air Traffic Services, currently operational at London Heathrow Airport.

Graduated: June 2019

Marc Voogt (BSc) – Operational benefits since the connection of Amsterdam Airport Schiphol with the Network Manager.

Key to enabling growth at Schiphol without compromising on safety, efficiency and the environment is to increase the predictability of traffic flows. Procedures put in place by Collaborative Decision Making (CDM) support predictable traffic flows not only at Schiphol but also in the surrounding airspace of Central Europe…Research is carried out into the effectiveness of CDM since the data -connection and the impact on operational partners at Schiphol and in the EUROCONTROL  network. The data-connection is identified to have improved the accuracy of take-off time predictions at Schiphol considerably with an average monthly increase of 6% of all departing movements regarded as having a predictable take-off time. Towards the network this take-off time predictability has increased significantly. In relation to similar major-hub airports, the increased take-off time predictability and the exchange of more accurate operational planning data between Schiphol and the NMOC are identified to have contributed to the significantly high compliance to imposed take-off times (93% of all departing movements) supporting stable Network Management. Although significant increases in delay throughout the EUROCONTROL network are increasingly affecting a stable planning of aircraft parking stands at Schiphol, indications for a reduction in stand-delay and other KPIs related to improved flow-efficiency at the airport are identified.

Graduated: April 2019

Tessa Rietema (BSc) – Capacity requirements analysis of civil air traffic in military controlled airspace

The determination of the capacity of the Lelystad Terminal Manoeuvring Area (TMA) is complex and brings different challenges. The opening of Lelystad airport for civil air traffic is the motivation to perform research into the capacity of the Lelystad TMA…The aim of this research is to help CLSK to determine the capacity factors and the capacity of the Lelystad TMA…By means of interviews and expert sessions with operational experts of CLSK, data is created to use during the research. With the data, the volume and capacity of the TMA is calculated. After this, a bottleneck analysis is conducted for the capacity of the handling process. The bottleneck in the handling process is the airport with its aircraft stands. After this, the TMA is the limiting capacity compared with the runway. Additionally, the annual maximum flight movements of 4,000 and 10,000 is feasible with the structure of the TMA. When the airport becomes operational for commercial traffic, the established capacity must be validated

Graduated: February 2019

Bas Broekstra (BSc) – Impact of Special Events on Airspace

Large-scale (e.g. Tour de France, Nuclear Security Summit, etc) or other special events can mean a temporary  increase in (concentrated) traffic in the airspace. These interruptions of normal operations can have impact on the airspace capacity and air traffic controller workload. The objectives of the research is to analyse and evaluate the impact of past events, to provide insight in the capacity impact of an event. To do so, operational requirements of different events are evaluated and analysed, with the aim to provide possible improvements to be better prepared for future events. Improvement could include procedural recommendations to manage special events in the airspace, to ensure that capacity is managed in efficient ways in the future. How do current procedures, to determine the impact of special events on airspace capacity, justify the impact on operations to stakeholders in Dutch airspace?

Graduated: July 2018

Marc Eijkens (BSc) – Analysis of Vertical Flight Trajectory Efficiency

The objective of this research is to analyse the effects of the current hand-over conditions on both horizontal and vertical flight trajectory efficiency. This analysis provides insight into the significance of how the current hand-over conditions affect operational efficiency. It will present an understanding of the impact on air traffic controller (ATCo) workload when this additional coordination is carried out. Besides analysing the impact on operational efficiency and ATCo workload, the research will provide possible solutions to the problem at hand. Solutions could range from procedural changes to technical innovations which will not negatively impact/increase controller workload.

Graduated: July 2018

Gijs Peters (BSc) – Impact Analysis on the Airside Infrastructure at Schiphol

The airside infrastructure layout of AAS is very complicated, and bottlenecks are easily formed. With this growing amount of movements, bottlenecks will occur more often and influence the capacity. Every stakeholder has its own perspective on the current problems and cooperation is difficult to achieve. The research gives an overview of the current bottlenecks at the runways, taxiways and gate/buffer areas to create more awareness of the seriousness of the problem. More awareness will stimulate a better cooperation between the main stakeholders of AAS’ airside infrastructure. Also, a list of possible solutions is created.

Graduated: July 2018

Martijn Ringelberg (BSc) – Airline Strategies’ Impact on Gate Occupancy

How do airline characteristics, ranging from business model differences to variation in actual procedures, affect AAS airside capacity? Schiphol airport is reaching its limit based on the cap of 500.000 movements per year. For reaching this amount of movements a lot of capacity constraints have already been tackled, not all of them however. There are numerous airlines operating at Schiphol, and all of these airlines have various differences and equalities ranging from differences between business models to differences between pilots. The fleet size or structure of an airline for example can impact the maximum number of movements per hour of a runway as bigger aircraft need to have more separation than smaller aircraft. Another issue is the communication between airlines and airport. This may lead to congestion as the airport wouldn’t be able to plan the gate capacity well in advance. When the impacts of airline strategies are known in more detail, AAS and LVNL would be able to plan accordingly to have less capacity congestion.

Graduated: July 2018

Roel Wouters (BSc) – Impact of Local A-CDM on the Operational Efficiency at Mainport Schiphol

AAS is at the final stage of having Airport- collaborative decision making (A-CDM) completely implemented. The last step is to connect the network manager and then AAS will be a CDM airport. The network manager is currently not yet connected and, therefore, not taken into account in this study since there is not any data available yet. Local A-CDM is currently implemented at AAS which includes the four other main stakeholders (Airport operator, Aircraft operator, ATC and ground handlers). Local A-CDM should improve the stakeholders’ operational efficiency by improving the predictability and decision making.  It is likely that A-CDM has been beneficial for the operation of each involved stakeholder at AAS. However, for all stakeholders it is still uncertain how much the operational efficiency has improved thanks to the implementation of local A-CDM. The aim of this study is researching how local A-CDM has exactly improved the operation’s efficiency for each involved A-CDM stakeholder at Mainport Schiphol until now, and what the exact benefits are.

Graduated: July 2018

Huib de Jong (BSc) – How can Schiphol transition to use of APOC in an effective way?

ATC controllers are respected for their high-performance jobs, training is consistent and on high quality level, still the individual controller has the opportunity to guide air traffic in the most efficient way for that moment. An analysis of ATC decision making (taxiway, gates, runway usage, approach and take-off routing), finding deviations and variations in the operation, should determine the current way of working and should form the basis to work towards APOC. In APOC, a key difference between the current situation is the way of information sharing and availability, this difference with the current situation should be analyzed, providing the insight how to transition towards the use of APOC. The results must provide how the current decision-making process impacts capacity and to what extent can these deviations and variations be reduced when APOC is used. Furthermore, what are benefits and what are the requirements to transition to this future situation. In addition, also maintaining sufficient flexibility in the operations after the decisions have been made.

Graduated: March 2018

Remsey Kanis (BSc) – Analyses of deviations and variations in the ground operations due to runway changes

Schiphol has the most runways in Europe with respect to major hub airports, this does not automatically translate to the highest ATMs. During the day runway use is changed, primarily because of the noise restrictions surrounding Schiphol. An analysis of the impact on the capacity on the ground and in air, is needed to determine, how this already complex change of runways also increases the complexity in other parts of the system. Included in the analysis the effect on TATs can be determined possibly through A-CDM data, also information from the ORS (Omgevingsraad Schiphol) must be considered as input. The results must provide an effect analysis on specific parts of the system and the reasoning, the related stakeholders need to be covered also the cost and benefits in operational sense need to be addressed.

Graduated: March 2018

Joep Boekhout (BSc) – Analysis of the effectiveness of the limitation/regulations in controlling airspace towards and from Schiphol

Air traffic controllers find the most efficient way to align aircraft towards the runway, maintaining separation requirements, trying to prevent delays, choosing the most fuel-efficient routes for airlines from and to the airport. Although in some cases regulations in the airspace are deemed necessary to cope with an increase in demand, on top of that pilots (airlines) tend to defeat the system by asking for directs (deviations), instead of following the rest. In addition, relaxing some airspace constraints did not have the effect of a higher utilisation of the airspace. The analysis should provide insight in the effectiveness of limitation/regulations used in the airspace. Possible input can be an aircraft priority study (KLM), that provides the airline with information which aircraft to speed up or slow down. The results of the research must provide air traffic controller with the impact of certain regulations and also airspace users with the insight on how their decisions impact the whole system. Included should be at least a list of the most used regulations with their impact/effectiveness and deviations by users including their impact as well. The customer wants to get insight in the current effectiveness of Network Manager regulations, and in particular the effect of airline/pilot behaviour on the effectiveness of regulations.

Graduated: March 2018

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