Using 4DT FMS data for green approach, A-CDA, at Stockholm Arlanda airport

How is it possible to perform a Green approach to a large airport like Stockholm Arlanda? The answer is simple in theory but complicated in live trails. By letting the aircraft flight management system (FMS) communicate with the ground the air traffic controller could receive information about what the aircraft intends to do, i.e. what flight path it will take including the time at the different positions. By providing exact 4 dimensional data to the ground, the pilot and the air traffic controller have the same accurate information about the aircraft flight path. It is therefore realistic to think that Green approach concept "on time-first serve" could be applied. It should be stated already now that the during the trials performed, the FMS 4DT has only been collected for technical analysis and not for air traffic control purposes. To provide information about the future position of the aircraft to the air traffic controller is not a new idea. Traditionally, we have been using radar plots to calculate the aircraft position and predict its future flight path (also using fixed data from flight plans.) In these trial/simulations, the flight management system (FMS) data bus in the aircraft was connected to the VHF radio making the FMS information available to the ground as well. This paper discusses how a Green approach is performed during live trails with the special tools developed for this purpose, and the benefits achieved. The paper also provides a brief summary from the simulation that took place in Malmo, Sweden. This simulation addressed the Green approach concept in a much higher traffic density then could be achieved during live trials at Stockholm Arlanda. The work presented here is part of an ongoing European Commission funded North European ADS-B Network (NEAN) Update Program 2+ (NUP2+), with one main objective being to study the use of down-linked trajectory information. The technical aspect by using an aircraft derived trajectory was studied in NUP2+, wh- ich is due to finish in 2007. What can be performed to improve the use of 4 dimensional trajectory (4DT)?