Italian authorities have released the AW609 tiltrotor prototype that was seized as part of their investigation into last year’s fatal crash of the model.
According to manufacturer Leonardo-Finmeccanica, following a recent decision taken by the relevant legal authority in Italy, the company has been able to resume development and testing work on the third prototype of the AW609 tiltrotor at its plant based in Cascina Costa. The aircraft was impounded in May 2016, shortly after its initial ground runs, by Italian prosecutors investigating the crash of the second AW609 prototype during high speed trials on Oct. 20, 2015.
In an interim statement released last month, Italy’s National Agency for Flight Safety (ANSV) reported that the accident aircraft experienced a kind of “augmented Dutch roll” while diving to an extreme maximum speed of 293 knots as part of the flight testing required for certification. The resulting oscillations appear to have led to a catastrophic in-flight breakup, resulting in the deaths of test pilots Pietro Venanzi and Herb Moran.
The accident flight was the first time the aircraft had reached a maximum dive speed of 293 knots with rear fuselage and tail fin modifications that were introduced in 2013 to reduce drag and enhance performance. Noting that the aircraft’s behavior at high speed was not completely predicted by the manufacturer, the ANSV recommended further review of the AW609’s aerodynamic behavior at high speeds, as well as a review of the model’s fly-by-wire flight control laws to ensure the effectiveness of pilot inputs.
In a statement, Leonardo said it continues to cooperate with all relevant authorities involved in the accident investigation of the second AW609 prototype.
“As noted in the interim report, all activities and tests performed during experimental flights of the AW609 have been conducted in accordance with the certification process outlined by the FAA [Federal Aviation Administration] and EASA [European Aviation Safety Agency],” the company stated. “While Leonardo-Finmeccanica awaits the final report and its accident conclusions, the company fully endorses — and already assumed as its own commitment — the initial safety recommendations issued by ANSV. Leonardo-Finmeccanica has already begun implementing them in its continued certification work.”
According to Leonardo, it plans to meet “the previously announced and expected program schedule,” with certification of the AW609 expected in 2018.
In the framework of experimental activities aimed at FAA certification, the third AW609 prototype will be relocated to the U.S. by the end of August, the company said. Meanwhile, the first prototype, currently in the U.S., is expected to return to Italy by the end of September.
