Wake vortex alleviation

This paper describes some of the National Aeronautics and Space Administration's (NASA's) recent and current research on aerodynamic techniques for minimizing the aircraft trailing vortex hazard. The potential benefits and operating problems of the more promising concepts are discussed. Recent flight-test results are presented which show that essentially total vortex alleviation can be achieved at a 3 nautical mile separation distance by oscillating the aircraft's lateral-control surfaces. While not operationally practical, these results suggest that it may be possible to minimize the wake hazard by exciting longitudinal instabilities.