The Gulfstream G650 Flight Test Accident: Lessons Learned

摘要

In April 2011, a Gulfstream Aerospace Corporation G650 crashed during takeoff from Roswell International Air Center Airport, Roswell, New Mexico. The flight was being operated by Gulfstream as part of its G650 developmental field performance flight test program. The National Transportation Safety Board (NTSB) determined that the airplane's angle-of-attack (α) exceeded the stall α in ground effect, resulting in a loss of roll control, the contact of the right wing with the ground, and the departure of the airplane off the right side of the runway. The stall occurred at an α that was below both Gulfstream's predicted in-ground-effect stall α, and the α threshold for the activation of the stick-shaker stall warning. This paper describes the analysis of recorded data and physical evidence conducted by the NTSB, and simulator and computational fluid dynamics studies conducted by Gulfstream, used to support the NTSB's conclusions. The paper also describes how the flight test data collected by Gulfstream during previous takeoffs of the G650 (including two previous uncommanded roll events) were sufficient to quantify the changes in lift due to ground-effect. Finally, the paper describes the development of erroneously low takeoff safety speed (V_2) targets, and their effects on the accident flight.