The lift force exerted on aircraft wings produces two counter-rotating vortices with long life-times in the wake of an aircraft. Especially during the critical landing phase wake vortices can endanger any aircraft following close behind. The following aircraft must therefore maintain a prescribed safety distance. The aircraft separation distance determines the frequencies of take-offs and landings on major hub airports. When air traffic is dense, this bottleneck limits airport capacity and, hence, results in aircraft holdings and delays.
A DLR project, called WIRBELSCHLEPPE (German for wake vortex), aims at reducing those bottlenecks that result from wake turbulence and at making it less dangerous to man and machine. As a core activity the project deals with constructive measures at wings, flaps and fuselage of large aircraft which allow to reduce the vortex strength in the far wake considerably. In another core activity systems are developed that enable the prediction of the evolution of wake turbulence and its detection from the ground and in the cockpit. DLR partners of the project are the Institut für Physik der Atmosphäre at Oberpfaffenhofen, Institut für Aerodynamik und Strömungstechnik at Braunschweig and Göttingen, Institut für Flugsystemtechnik and Institut für Flugführung, both located at Braunschweig.
Research activities in the field of aircraft wake vortices are also funded through several projects by the European Commission (WakeNet I und II, C-Wake, S-Wake, I-Wake, ATC-Wake, AWIATOR). DLR is a major partner in all these EU projects. The endeavour aims at increasing the competitiveness of the European air traffic economy.