Sikorsky-Boeing’s SB-1 Defiant Reaches 205 Knots During Flight Test

The SB-1 Defiant aircraft developed by Sikorsky and Boeing reached its fastest speed yet during a recent flight test.

"Exceeding 200 knots is significant also because it's beyond any conventional helicopter speed, and we understand that speed and low-level maneuverability is critical to the holistic survivability in the Future Vertical Lift environment," Jay Macklin, Sikorsky's business development director for FVL, told reporters on June 16.

The SB-1 has been offered to the US Army which is looking for a Future Long Range Assault Aircraft (FLRAA). The Army in March awarded Sikorsky-Boeing and Bell competitive demonstration and risk-reduction (CDRR) contracts through other transaction authority agreements for FLRAA. The CDRR phase will last two years, followed by a downselect to one vendor.

The helicopter flew for the first time publicly in February, reaching a speed of 140 knots using less than 30% of engine power.

Bill Fell, lead pilot for the SB-1 Defiant, said the helicopter was able to reach 205 knots using less than 50% of the installed propulsor power.

The 23,000-pound Defiant is based on Sikorsky's X2 platform and is a joint multi-role medium-class demonstrator that features a lift system using two coaxial main rotors and a rear-mounted pusher propulsor to solve the problem of retreating blade stall. By using two main rotors that spin in opposite directions, the Defiant counters the tendency of helicopter blades to generate uneven lift forces at high speeds, which severely limits the capabilities of current rotorcraft.