Holding support for Amsterdam Area Control

Before COVID-19 holding operations were a common phenomenon at busy European airports. At London Heathrow holding operations are an integral part of the arrival management concept. At other airports, such as Schiphol, holding operations are more incidental to manage short peaks in the arrival stream and of course in case of unforeseen shortage of arrival capacity due to weather. Holding operations are safe and controllers are familiar with them, so why would they need support for holding operations?

Clearly controllers do not need system support for holding operations today. However, controllers may need system support in the future. To understand why, two points need to be considered:

  • the future TMA concept for Schiphol airport and
  • limitations associated with holding operations.

To start with the first point: the airspace redesign program (programma luchtruimherziening) intends to introduce a new TMA concept for Schiphol with 3D separated arrival and departure routes, with continuous climb and continuous descent operations. Fixed arrival routes, or RNP-1 routes, are part of the future TMA concept. The use of fixed arrival routes limits the amount of delay that can be absorbed in the TMA. As a result delay absorption will in part be shifted from the TMA to Area Control. The effect of this shift is that Area Control will have to deliver traffic to the TMA closer to the planned time.

The second point to consider is the nature of holding operations. The duration of an orbit flown in a holding pattern varies with altitude and varies from one aircraft to the other. For area controllers it is difficult to time the TMA entry for aircraft that are holding. One of the contributing factors to this limitation is the timing of the approach clearance. Depending on which leg the aircraft is, outbound or inbound, the time of TMA entry varies.

So, there is a challenge for the new TMA concept based on fixed arrival routes: Area Control needs to absorb more delay and to deliver traffic closer to the planned time to the TMA, which in turn may be increasingly difficult once aircraft need to fly holding patterns. The solution for this challenge may be found in the provision of system support to the controller.


This KDC study on this subject was performed by a consortium of MovingDot and NLR. The study provides high level holding support concepts for Area Control. The purpose of the support function is provide time predictions for the TMA entry time of aircraft during holding, and to provide control strategies to achieve the target TMA entry time. The report provides a list of solutions/concepts based on two solution categories: ground-based solutions and airborne solutions that can provide holding support for controllers.


The full report with all the results and solutions can be downloaded below.

Download full report