Sikorsky and Boeing have provided the first look at their new high-speed helicopter known as the SB>1 Defiant. The aircraft has been developed for the US Army’s Joint Multi-Role Technology Demonstrator project, the precursor to the Future Vertical Lift (FVL) programme which aims to replace ageing helicopters across Department of Defence (DoD) services.
The SB>1 Defiant –a scaled up militarised version of Sikorsky’s X2 aircraft – is designed to fly at more than 250kts (288mph), which outpaces all current aircraft in the fleet. The design features coaxial rotors which create very little downwash in comparison with a traditional helicopter. With the addition of a pusher propeller, the aircraft can move forwards and backwards in a level attitude or pitch 20° nose up or down without moving laterally.
The SB>1 Defiant uses Honeywell T55 turboshaft engines (also used to power the CH-47 Chinook), which means the helicopter currently falls short of the army’s 229nm range requirement. The production aircraft is modelled with engines that meet this requirement in anticipation of fuel efficiencies. Data from SB>1 Defiant will help the army develop requirements for new utility helicopters expected to enter service in the early 2030s.