Curved approach procedures enabled by a Ground Based Augmentation System

As the international air traffic increases and becomes more and more complex there is a growing demand for new operational procedures where noise and terrain issues are being considered increasingly. The proceeding integration of satellite navigation into aviation is paving the way for more flexible and complex approach procedures. Operationally, the Required Navigation Performance (RNP) determines the specifications an aircraft has to fulfill to perform a specific procedure. The use of a Ground Based Augmentation System (GBAS) could provide the required accuracy and integrity while loosening the requirements on the aircraft equipment. GBAS is certified as a system providing CAT I capabilities for a precision approach in an ILS “Look-Alike” fashion but in addition the architecture of a GBAS already contains the possibility to provide data for complex procedures, called Terminal Area Paths (TAP). Within this work, the data architecture of TAP messages was incorporated into a cockpit simulator and trials regarding flyability were conducted. For every waypoint in a TAP, a specific horizontal and vertical sensitivity value can be assigned. Therefore, different values for this sensitivity value were investigated during simulated approaches that were flown manually and automatically. Different means of displaying the deviation information were provided to the pilots. The results in terms of Flight Technical Error (FTE) for different approach paths flown automatically and manually are presented. An analysis of the different waypoint sensitivities and means of displaying deviation information is going to be carried out. Based on the observed FTE values, a first link between GBAS TAP performance and existing RNP values for the approach phase of a flight is going to be established.