Bell's fourth flight test vehicle. Photo courtesy of Bell
Bell said its fourth flight test vehicle for the Bell 525 has taken flight. The fifth and last flight test vehicle will join the fleet later this year.
The entire fleet has flown more than 400 hours since resuming the flight test program in July 2017 since the first prototype's crash. Testing has included flying in cruise mode, cold weather testing, and cabin and component fatigue testing.
The No. 1 prototype crashed and impacted terrain near Italy, Texas, July 16, 2016, after the tail boom separated from the fuselage in flight. The NTSB found severe vibration to be the probable cause.
The FAA said last month that it had issued a final set of special conditions that Bell must satisfy toward achieving type certification of the 525. The special condition will required a suitable mode annunciation to be provided to the flight crew "for events that significantly change the operating mode of the system, but do not merit the traditional warnings, cautions and advisories,” the FAA said.
Bell aims to achieve certification of the Relentless in 2019.