Gulfstream G650 Flight-Test of Electrically Powered Fly-by-Wire Backup Flight Control Actuation System

 

On January 12, 2011, Gulfstream Aerospace announced that Gulfstream’s test pilots and flight-test engineers had recently made business-aviation history by flying the Gulfstream G650 flight-test aircraft for the first time using only an electrically powered, fly-by-wire backup flight-control actuation system. Gulfstream’s Serial Number (S/N) 6001 flew for a total of 3 hours and 33 minutes on Dec. 21, 2010.

Test pilots Jake Howard and Gary Freeman along with flight-test engineers Bill Osborne and Nathaniel Rutland evaluated the fly-by-wire system in electric backup actuation mode for 2 hours and 20 minutes of the flight, performing five landings with the backup system engaged. According to the announcement, there was no difference in handling qualities between the electrically and hydraulically powered modes.

Typically, fly-by-wire uses a third hydraulic system to provide redundancy in the event of a dual hydraulic system failure. However, Gulfstream’s fly-by-wire architecture uses electric backup hydraulic actuators (EBHA): electrically controlled actuators that are primarily hydraulically powered but offer electric power as a backup. A self-contained hydraulic reservoir and motor pump allow full operation should hydraulic loss occur.