Green Approaches without Trade-Off: Final Results from the FAGI-Project

Kurzfassung

A fundamental contribution to satisfying future demands in air transport like gain of capacity, reduction of environmental impact, improved flight efficiency and high predictability is often the term “4D”. However, having a look at today’s fleet only one out of nine aircraft is currently able to fulfill a requested time of arrival with high accuracy. Therefore, a successful transition to a 4D-ATM environment strongly depends on how especially the unequipped aircraft without an onboard flight management system (FMS) fit into the concept. In 2007-2009, the FAGI (Future Air Ground Integration) project investigated a new concept facilitating the transition to a 4D-trajectories based ATM operations. The main element of FAGI’s 4D concept for an advanced TMA handling is the late merging of all arriving traffic. Before merging, arriving aircraft are separated procedurally by staggering them laterally in an extended TMA (E-TMA). When entering the E-TMA, a time constraint for the merging point is assigned to each aircraft. The late merging point is located just before the final approach. The early assignment of time constraints enables arriving aircraft to fulfill the requested time in an efficient way, i.e. speed adaptation. Therefore, the E-TMA is rather big (80-120NM radius). If speed variation is not enough to reach the constraint, strategic path stretching can be used to delay the aircraft further. Parallel routes from every entry point to the late merging point enables each aircraft to fly its own optimum speed and altitude profile until merging. In order to cope with the new demands, the question how human operators can be supported in performing the described tasks in the best way is crucial. New automation in terms of advanced 4D-arrival managers (AMAN) is necessary to help the controller with appropriate time-based planning functions for all aircraft. The 4D-AMAN permanently analyses the traffic situation and produces advisories for highly efficient guidance of all aircraft. Ghosting (i.e. projection) of equipped aircraft to the centerline, targeting of unequipped aircraft’s optimum position and an advisory stack assisted eight professional controllers during the FAGI real time simulation campaigns. Since the concept does not penalize FMS-unequipped aircraft (compared to today’s operation) the overall system performance benefits from every single aircraft flying advanced approach procedures. Thus, even with a small percentage of 4D-capable aircraft traffic is handled more efficiently and environmentally friendly. This paper presents the results from the real time simulations performed in the final validation campaign. The human-in-the-loop simulations were performed using a generic airport layout with one runway. The FAGI route structure had four static entries, with one of them being aligned to the landing direction. The simulated scenarios contained 33-36 aircraft with 10%-90% of them being FMS equipped; simulation time was one hour. The real time simulations and several simulations in automatic mode proved the high potential and feasibility of the FAGI concept. In addition to the overall fuel and noise reductions, the concept also proved to reduce separation violations and controllers’ workload. Results from these simulations are discussed in the paper, especially concerning the above mentioned controller support tools, the fairness between 4D-capable and –incapable aircraft, and quantifiable environmental improvements.