The Sikorsky-Boeing SB-1 Defiant compound helicopter made its first flight at Sikorsky’s West Palm Beach, Florida site on 21 March.
The Defiant flew without its rear propeller engaged; moving slowly forward, rotating around its centre axis and hovering not far above the tarmac in a video released by Sikorsky and Boeing. The flight lasted more than 30min, says the Sikorsky-Boeing team.
“We are thrilled with the results of today’s flight and look forward to an exciting flight test program,” says Dan Spoor, vice president of Sikorsky Future Vertical Lift.
The Sikorsky-Boeing team adds that it considered the rotorcraft’s performance of low-speed maneuvers to be a success, though it declined to specify what movements the aircraft performed.
“After today’s successful flight we will analyse the data and build out the specifics of our flight test programme,” says Sikorsky-Boeing. “Over the coming weeks and months, we are planning to conduct additional test flights, expanding the envelope and providing the US Army with the necessary, robust, and relevant data in a timely manner that will enable them to make fully informed decisions as they pursue the Future Vertical Life (FVL) programme.”
With its two counter-rotating, coaxial main rotors and rear-mounted pusher propeller, the SB1 Defiant is designed as a technology demonstrator in the US Army’s Joint Multi-Role-Medium Technology Demonstrator programme. That demonstration programme is a precursor to the service’s FVL programme, for which the SB-1 would be a Capability Set 3 aircraft, a medium-sized utility replacement for the Sikorsky UH-60 Black Hawk.
“Defiant is designed to fly at nearly twice the speed and has twice the range of conventional helicopters while retaining the very best, if not better low-speed and hover performance of conventional helicopters,” says Spoor. “This design provides for exceptional performance in the objective area, where potential enemy activity places a premium on maneuverability, survivability and flexibility.”
Defiant is competing against the Bell V-280 tiltrotor which has been flying for more than a year and in January 2019 reached its top speed of 280kt (518km/h).