The Sikorsky-Boeing SB>1 Defiant™ helicopter – a demonstrator for a medium-lift aircraft and a joint-development for the U.S. Army’s Joint Multi-Role-Medium Technology Demonstrator program — completed its first flight March 21 at Sikorsky’s West Palm Beach, Fla., location. According to the co-developers, the SB>1 will help to the U.S. Army define its next generation of military helicopters as part of its Future Vertical Lift program.
The SB>1 Defiant aircraft is based on Sikorsky’s X2 technology, a high-speed compound helicopter for vertical take-off and landing (featuring coaxial rotors), with a T55 turboshaft engine for flight speeds up to 250 kn (290 mph; 460 km/h.) According to the Sikorsky and Boeing, the SB>1’s initial flight is the culmination of significant design, simulation, and test activity to demonstrate the X2 technology.
“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,” stated Dan Spoor, v.p., Sikorsky Future Vertical Lift. “This design provides for exceptional performance in the objective area, where potential enemy activity places a premium on maneuverability, survivability and flexibility.”
The co-developers claim that the two coaxial main rotors and a rear-mounted pusher propulsor are part of a design that is "a leap forward in technology," to achieve the U.S. Army’s goal of increased speed and range plus improved maneuverability and survivability, but with cost-effectiveness.
The SB>1 was originally scheduled for its first flight in April 2017. The "SB>1" designation refers to the first phase for the development, which was led by Sikorsky, a Lockheed Martin subsidiary. Boeing will lead the second phase, focused on demonstrating the helicopter’s mission systems
The SB>1 Defiant is participating in the U.S. Army's Joint Multi-Role-Medium Technology Demonstrator program. Data from Defiant will help the Army develop requirements for new utility helicopters, expected to enter service in the early 2030s.
“The design and development of Defiant has revealed the capability advancement that is truly possible for Future Vertical Lift,” according to David Koopersmith, v.p. and g.m. for Boeing Vertical Lift. “Clearly, the performance, speed, and agility of Defiant will be a game changer on the battlefield and we look forward to demonstrating for the U.S. Army the tremendous capabilities of this aircraft.”