To regulate and mitigate noise impact of an airport on the surrounding communities, aircraft noise models are used to assess the impact. For these models, flights are modelled based on standard procedures of consecutive steps of speed and altitude changes and their corresponding delivered thrust. Under these procedures, however, lie a number of assumptions that could significantly alter the actual flown trajectory and thus noise pollution. Using real world data including data from the Aircraft Condition and Monitoring System (ACMS) and measurement data from the Noise Monitoring System (NOMOS), a comparison can be made between the estimated and real flight profiles.