The Trailing Vortex Wake Hazard: Beyond the Takeoff and Landing Corridors

This paper focuses on issues related to the trailing vortex wake hazard beyond the takeoff and landing corridors. The operational procedures adopted by the FAA in the 1970s for avoiding wake turbulence encounters in the take-off and landing corridors have been very successful in providing commercial aviation with a high degree of safety. However, there is a growing body of evidence that encounters well beyond the immediate airport area could also prove to be hazardous. A review of commercial airline accidents for which a wake vortex encounter was considered to be a contributing factor in the accident are reviewed. Another problem that is addressed is wake encounters at cruise altitude. With the introduction of the regional jet transports into the commercial fleet we have created a very large disparity in the size of aircraft that can cruise at the same altitude. Furthermore there is evidence that wake encounters at cruise altitude do occur and should be investigated more extensively than has been done to date. In the current study the vortex induced loads created by wake vortices at cruise altitude are examined. The two cases that are presented include penetration perpendicular to the trailing vortex wake and penetration along the vortex core axis. The cross track penetration focuses on the structural loading while the along track penetration examines the potential roll excursion from the intended flight path.