The Sikorsky–Boeing SB-1 Defiant compound helicopter completed its initial test flight as a fully-configured aircraft, Boeing announced.
The SB-1 Defiant (stylized as SB>1) is the Sikorsky/Boeing entry for the U.S. Army’s Future Vertical Lift (FVL) program, succeeding the Joint Multi-Role (JMR) initiative.
The aircraft has a compound helicopter design with a pair of counter-rotating rigid coaxial main rotors and one pusher propeller. Compared to a conventional helicopter, this design offers a 100-knot speed increase, a 60% combat radius extension, and 50% better performance in high-hot hover performance.
The Defiant demonstrator will be powered by the Honeywell T55 turboshaft engine, which powers the CH-47 Chinook tandem rotor heavy-lift helicopter. A new engine, the Future Affordable Turbine Engine (FATE), is being developed by GE Aviation for the FVL helicopters including the SB-1.
The design will have a cruise speed of 250 knots (290 mph) and a range of 229 NM (when powered by FATE engine).
The aircraft performed its first flight on March 21, 2019.