Leonardo is preparing to start icing trials with the third prototype of the AW609 tiltrotor. The aircraft has been undergoing ground testing since May and started initial flight tests at the company’s facility in Philadelphia in recent weeks in support of FAA certification. The latter remains on track for 2018, according to the company.

Leonardo says that initial testing has allowed avionics and all systems to be fully tested. During initial flights, the aircraft performed basic hovering and manoeuvring and patterns around the airport, concluding with hover landing. 

Additional flights up to altitudes of 4000 feet with short takeoff and landing (STOL) are planned shortly. 

The third prototype, which was assembled in Italy, joins the other flying prototype (A/C 1), which arrived in Philadelphia in August. Test activities with A/C 1 resumed in April. The aircraft had been grounded since the loss of the second prototype in a fatal accident in October 2015.

The icing trials will take place in Marquette, Michigan, through the winter. The tests will ensure the AW609 can fly in known icing conditions and reach operational standards not currently available in any other commercial aircraft. 

The fourth prototype is now located within the main production area of the Philadelphia facility’s assembly line. The transition to the first production build aircraft is planned for 2018.