Piasecki Aircraft has flown the X-49A experimental compound helicopter for the first time. The modified Sikorsky YSH-60F, with wings and tail-mounted vectored-thrust ducted propeller (VTDP), made the 15min flight on 30 June at Boeing’s Wilmington, Delaware test centre.
The first flight involved hovering, pedal turns and slow forwards and sideways flight using the Piasecki-designed VTDP for anti-torque, directional and trim control, says vice-president John Piasecki.
The flight was a milestone for Essington, Pennsylvania-based Piasecki, which has been working on compound helicopters for decades, flying its first-generation “Ring-Tail” ducted propeller on the 16H-1 Pathfinder in 1962.
The second-generation VTDP provides significantly more hover efficiency, says Piasecki.
Dubbed the SpeedHawk, the X-49 is being developed with funding from the US Army's Aviation Applied Technology Division to demonstrate the ability to increase the speed of existing helicopters to 200kt (360km/h).
The VTDP replaces the tail rotor and provides thrust for forward flight, while the wing unloads the rotor and allows the helicopter to fly faster.
Versions have been studied for the Bell AH-1W, Boeing AH-64 Apache and CH-47 Chinook as well as the Sikorsky UH-60 Black Hawk and SH-60 Seahawk.
Boeing is providing flight-test support, and Piasecki says the US Army plans to provide an additional $3.3 million in funding to continue flight testing.