The Leonardo AW609 TiltRotor program is moving ahead as flight testing gains momentum.
The troubled program, which saw the second prototype (N609AG) crash on 30 October 2015, killing two of Leonardo’s test pilots, is moving ahead with flight testing in 2017, with FAA type certification expected in 2018.
The AW609 was expected to start icing trials soon following ground testing of it’s third prototype in Philadelphia. According to a press statement, the aircraft performed unrestrained ground testing, which was followed by hover tests and circuits around the airport. The flight test envelope is expected to be expanded to altitudes of up to 4000 feet.
The second prototype crashed during flight testing when the aircraft was dived to a speed of 293 knots, 8 knots faster than any previous prototype had achieved. According to a report released by investigation agency ANSV, the crash was caused by the onset of oscillations on the roll axis of the aircraft during it’s third high speed dive of the day. The pilot in command attempted to counteract the roll, but the flight computer’s control laws caused the aircraft to behave unexpectedly, eventually culminating in what the investigation described as an “augmented Dutch roll”. The oscillations were experienced by the other prototypes as well, although to a lesser degree. The aircraft in question had also been flying with a new aft section and tail-fin for the first time on the day of the accident.
The test fleet was grounded after the accident, setting back the program and delaying its entry to service significantly.