Modern aircraft with 4D-Flight management system are able to plan approaches which are fuel-efficient and noise optimized. That is
operation conceptusually achieved by usage of Continuous Descent Approach procedures planned with engines idle (-> “Glider”). A large disadvantage of the procedure is that, once the idle descent is commenced, it is hardly possible to react on ATC instructions. Both shortening and extension of lateral path would worsen fuel and noise efficiency, even compared to today’s flown low-drag-low-power approaches. Furthermore, allowing aircraft to fly there own preferred vertical and speed profile on a joined lateral path results in a suboptimal separation causing a break-in of capacity. Thus, noise efficient approaches are currently used in low traffic scenarios only. Using the late merging point concept combined with time based separation FAGI shows a possible solution for fuel and noise efficient handling of a traffic scenario in an extended terminal manoeuvring area environment. Aircraft which are not 4D-capable are integrated by means of a ground based 4D-guidance module. Future high-precision and reliable satellite navigation technologies (Galileo / GPS+) are beneficially included as a basis for 4D-guidance.
Dipl.-Inform. Alexander KuenzGerman Aerospace Center DLR Member of the Helmholtz AssociationInstitute of Flight Guidance Lilienthalplatz 7 38108 Braunschweig Germany +49-531-295-3008 (phone)+49-531-295-2550 (fax)E-Mail: mailto:Alexander.Kuenz@dlr.deInternet: http://www.dlr.de/Braunschweig