Accession Number : ADA318103

Title :   Flight Test Investigation of Rotorcraft Wake Vortices in Forward Flight.

Descriptive Note : Final rept.,

Corporate Author : FEDERAL AVIATION ADMINISTRATION TECHNICAL CENTER ATLANTIC CITY NJ

Personal Author(s) : Teager, Stephen A. ; Biehl, Keith J. ; Garodz, Leo J. ; Tymczyszym, Joseph J. ; Burnham, David C.

PDF Url : ADA318103

Report Date : FEB 1996

Pagination or Media Count : 95

Abstract : This report presents the results of helicopter flight tests and wake vortex measurements which were designed to provide data necessary for the assessment of hazards to following aircraft. The tests described in this report were conducted using small probe airplanes and a Laser Doppler Velocimeter for wake vortex measurements during forward-flight helicopter operations. Four helicopters, having weights ranging from 7,600 to 70,000 pounds, were used in the tests as the wake vortex generating aircraft. Wake vortex strength and decay characteristics as determined from the flight test results are discussed. In the absence of encounter measurements for the case of hover flight, it is recommended that small airplanes, at the same altitude and downwind of a hovering helicopter, maintain at least 500 feet of separation.

Descriptors :   *FLIGHT TESTING, *VORTICES, *HELICOPTERS, *WAKE, *HOVERING, MEASUREMENT, PROBES, AIRCRAFT, HAZARDS, TRAILING VORTICES, FLIGHT, STRENGTH(GENERAL), DOPPLER SYSTEMS, LEVEL FLIGHT, DECAY, ROTARY WING AIRCRAFT, LASER VELOCIMETERS.

Subject Categories : Helicopters
      Fluid Mechanics

Distribution Statement : APPROVED FOR PUBLIC RELEASE