Finmeccanica Helicopters is “confident” that it understands the cause of the late October 2015 crash of a prototype AW609 tiltrotor in which two test pilots were killed.

Speaking on the sidelines of the Heli-Expo show in Louisville, Clive Scott, AW609 programme manager, said: “We have a very good understanding of the events and have a view of the most probable causes. That is what’s leading us to say we are expecting to resume flight tests.”

Depending on the outcome of the ongoing accident investigation, which is being led by Italy’s ANSV agency, “it is possible there could be some modifications to the aircraft”, he reveals.

Scott declines to divulge details of any potential design changes, but says: “We don’t expect the modifications to impact on the certification programme.”

Although the company's remaining flight-test article has been voluntarily grounded since the crash, Scott says it has been trying to “limit the impact of the accident”. It has been “in close collaboration” with the authorities during the accident investigation and “towards the return to flight”, he notes.

Ground runs of the company's third prototype are due to commence shortly, with the aircraft having been rolled out in Italy.

Scott says long lead-time components – notably the wings and fuselage – for the initial production aircraft are already being built, with first customer delivery due in 2018.

He says the “close-knit” AW609 team was deeply affected by the “shock” of losing their two colleagues, and were also faced with the additional burden posed by the accident investigation.