Gulfstream has resumed test flying its G650, and two of the aircraft are now flying as part of the flight-test program. The program was suspended after the fatal April crash of one of the aircraft engaged in certification test flights. Flight testing resumed at the end of May, when S/N 6001 restarted the flight-test regime with an interim restriction that temporarily increased V speeds and limited maximum angle of attack on takeoff . S/N 6004 rejoined the program two weeks later, on June 11.
At press time, the company expected the remaining two G650s to fly again soon as well. “We have conducted all the necessary reviews to assure ourselves that we can safely resume the flight-test program at this point,” said Pres Henne, Gulfstream’s senior vice president for programs, engineering and test. “We have worked closely with the FAA in this process and received the agency’s concurrence to resume flight testing. It is our responsibility to move forward with the flight-test program, and we will do so in a safe and prudent manner.”
S/N 6002 crashed at Roswell International Air Center Airport on April 2, while conducting a low-speed, high-angle takeoff test with a simulated engine failure. The flight-test aircraft was equipped with a telemetry downlink, which–along with the cockpit voice and data recorders–likely provided investigators with much information regarding the aircraft’s final flight.
While the flight-test fleet was grounded, Gulfstream made no modifications to any of the airframes other than the routine maintenance and software upgrades that would have been carried out in the course of the flight-test program.
At the time of the accident, the G650 flight-test program had accomplished 470 flights and accumulated more than 1,560 of the estimated 2,200 flights hours required for certification. Rather than add another aircraft to the test program, Gulfstream outfitted the remaining four test aircraft with additional instrumentation to complete the remaining scheduled tasks of S/N 6002, which was assigned to evaluate the aircraft’s systems as well as its takeoff and landing performance. According to Gulfstream, much has been accomplished in nearly every area of the test program, with the completion of speed and altitude calibration, flutter, powerplant and auxiliary power unit operations, fly-over noise, and water ingestion testing among others.
Despite the modifications to the flight-test schedule, the manufacturer still anticipates that it will achieve certification later this year, with entry into service next year.