AW609 resumes flight tests

The first Leonardo AW609 tiltrotor prototype has resumed flight testing in helicopter and airplane modes, the manufacturer has announced.

“Flight testing activities will continue to take place in Arlington, Texas, with plans to soon fly the AW609 to Philadelphia and ultimately relocate the aircraft at [Leonardo’s] facilities in Italy,” the company said in a statement. “The third prototype, assembled and ground tested in Italy, is being shipped to Philadelphia in preparation for certification flight testing activities planned later this year.”

Flight testing had been on hold since the fatal crash of the second prototype on Oct. 30, 2015, which killed test pilots Herb Moran and Pietro Venanzi.

In an interim statement released on June 23, 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.

The accident flight was the first time the AW609 reached a maximum dive speed of 293 knots with rear fuselage and tail fin modifications — enhancements that were introduced in 2013 to reduce the aircraft’s 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 May, shortly after its first ground runs, the third AW609 prototype was sequestered by Italian prosecutors in conjunction with their investigation into the accident. It was then released back to Leonardo in July.

At the time of the third prototype’s release, the manufacturer said it continues to cooperate with all relevant authorities involved in the investigation of the second AW609 crash, and still plans to meet “the previously announced and expected program schedule” to certify the aircraft in 2018.