Flugerprobung
Flight testing for the maximum operating speed of Mach 0.925 was announced as completed on May 4, 2010. Gulfstream reported on August 26, 2010 that the G650 hit a maximum speed of Mach 0.995 during a dive as part of its 1,800-hour flight test program. In April 2011, a G650 crashed shortly after lift off. The cause was determined to be related to the speeds carried out for the single engine take off run. The G650 test aircraft were grounded until May 28, 2011, when the remaining test aircraft were allowed to return to flight testing.