Information of TTFLY: Leonardo's first AW609 prototype has resumed flight testing.

The manufacturer voluntarily suspended the prototype's flight tests after the Oct. 30, 2015, crash of the No. 2 prototype.

The No. 2 prototype crashed in October after breaking up in midair during high-speed tests southwest of Leonardo Helicopters’ Italian headquarters in Cascina Costa. Both test pilots were killed. Italy’s ANSV accident investigation agency late last month said they are assessing what role an unexpected feature of the AW609's high-speed flight-control software may have played in a prototype's fatal October in-flight breakup in Italy.

Leonardo said flight testing will take place in Arlington, Texas, and it plans to fly the aircraft to Philadelphia before ultimately relocating it to Italy.

The third prototype, which has been assembled and ground tested in Italy, is being shipped to Philadelphia in preparation for certification flight testing activities planned later this year.