Preparation and conduction of a simulator study for analysis of wake encounter hazard

Kurzfassung

Wake vortex perturbations are one of the reasons that do not allow an increase in the airspace capacity. The current minimum separation distances between consecutive aircraft to avoid hazardous wake encunters should be redefined in order to allow the air traffic to grow, but without endangering any aircraft. Several studies to understand the nature of the wake vortex have been carried out since the 1950s, in order to assess wake vortex encounter hazard. Pilots are a valuable source for wake vortex assessment, due to their knowledge and control of the aircraft. Todays software tools permit the simulation of realistic wake vortex models, taking into account the different deformation phases of the wake vortices. The implementation of such models into motion simulators permits the simulation of wake encounters saftely and reallistically. These improvements in the wake vortex research field endorse this master thesis, in which the influence of the wake vortex age on the wake vortex encounter hazard is to be analysed. This master thesis introduces the wake vortex in the first chapter, along with the encounter severity and the wake vortex deformation. The methods to evaluate wake encounter hazard are described and the pilot campaign performed with five-pilots in the loop is explained. For the pilot campaign carried out in the frame of this mater thesis curved wake vortex generated with Large Eddy Simulations (LES) were implemented in the motion-based simulator, A320 AVES, located at the German Aerospace Center (DLR) in Braunschweig. In total 100 encounters were simulated with five different wake vortex ages. All the encounters were flown manually. Altogether 7 percent of the encounters were not accepted by the pilots. The most outstanding outcome of this study is that the worst wake vortex encounters rated were during the linking phase at a vortex age of 120 seconds instead of being with a stronger younger wake vortices with 80 seconds of age.