FLIGHT TESTING OF STEEP PRECISION APPROACHES BASED ON GBAS

Abstract

As the international air traffic becomes more and more complex (a growth of 2.3% from 2006 to 2007, 57% from 1997 to 2007 [7]) there is a growing demand for new operational procedures. Especially quiet and fuel efficient approaches are desired. A Ground Based Augmentation System (GBAS) provides more flexibility than current precision landing systems. Therefore, it is identified as a potential key technology for providing different approach procedures tailored for unique demands at a special location. Especially steep precision approaches have a high noise reduction potential as the aircraft can stay at a higher altitude for a longer time. During this work approach procedures based on GBAS with slightly higher glide path angles than usual (4.5° - 5.5° instead of 3° - 3,5°) were investigated. Therefore a simple software simulator of a Multi Mode Receiver (MMR) was created and integrated into a Generic Experimental Cockpit (GECO) simulator. The Final Approach Segment (FAS) data for an ILS look-alike approach (glide path angle 3.5°) and for approaches with steeper glide path angles were validated in this simulator. Pilots were familiarized with the new approaches in the simulator and some questionnaires were filled out regarding the workload and flight technical demands for the pilots. The simulation architecture is going to be described in this paper and the results of the simulator trials are going to be presented. After the GBAS Landing System (GLS) Approaches were validated in the simulator the FAS data blocks were transferred into an actual ground installation at the research airport Braunschweig-Wolfsburg. The FAS Data was checked with ground trials and some flight trials were conducted to verify the data gathered in the simulator trials.