Sikorsky and Boeing are jointly producing a medium-lift-sized demonstrator called the SB>1 Defiant. Photo courtesy of Sikorsky
In Palm Beach, Florida, a team of Sikorsky and Boeing engineers is diligently progressing toward a 2018 first flight of the SB-1 Defiant next-generation rotorcraft.
“We continue to achieve milestones in support of flying Defiant in 2018,” the company said in a prepared statement emailed to R&WI. “The Sikorsky-Boeing team continues its rigorous testing program ahead of SB-1 Defiant’s flight later this year.
Sikorsky achieved first flight with the Defiant’s smaller but older relative, the S-97 Raider, in 2015. It built two Raiders before being acquired by Lockheed Martin, crashed one in 2017, grounded the program for 10 months and returned to flight in June.
SB-1 Defiant, a third-generation X2 aircraft, is scheduled to fly after successful completion of integration testing, ground testing, establishment of the aircraft’s do-not-exceed limits and testing of flight-critical components on the propulsion system test bed. The PTSB is a ground-test article to prove out many of the mechanical attributes of the aircraft’s powerplants, rotors and prop to reduce risk prior to the prototype taking flight.
Raider, aimed at the Army’s capability set-1 requirements for a scout/attack aircraft, proved out the operational effectiveness of the basic design of relying on coaxial rotors for lift and a combination of rotors and an aft pusher propeller for forward flight.
Defiant is officially the Sikorsky-Boeing entrant for the U.S. Army’s joint multirole technology demonstration program. It’s only competitor in JMR-TD is the Bell V-280 advanced tiltrotor. The Army aims to use the data gathered in JMR-TD to inform its official requirements for the Future Vertical Lift (FVL) family of next-generation helicopters.
Both the Defiant and V-280 are aimed at satisfying the Army’s requirement under capability set-3, or “medium” variant that would be analogous to a legacy UH-60 Black Hawk. A Bell official told R&WI a broad area announcement for FVL capability set one — the armed aerial scout/attack variant — is “imminent.”