Information of TTFly: Bell Helicopter, meanwhile, is proceeding with ground-based testing and certification work for the 16-seat 525 helicopter, says Donnelly, speaking to analysts on a second quarter earnings call.

Parent company Textron is not yet able to estimate the length of the self-imposed 525 grounding or the impact on the certification schedule, Donnelly says.

But Textron remains “committed to the Bell 525 programme and we’ll work to ensure the aircraft will be a safe, reliable and high-performance helicopter”, Donnelly says.

The US National Transportation Safety Board has not yet released a preliminary report about the accident.

The crashed 525, Bell’s first flying prototype, was on a routine test flight southeast of the flight test centre in Forth Worth, Texas.

Bell’s schedule now calls for delivering the 525 about a year late near the end of 2017.

The 525 is the first commercial helicopter to apply for certification with fly-by-wire flight controls.