Sikorsky Defiant Moves Closer To First Flight

 - August 9, 2018, 6:04 PM

Sikorsky and development partner Boeing inched closer to the first flight of the SB-1 “Defiant” compound helicopter prototype this week, receiving FAA registration number N100FV and officially designating it the “S-100,” serial number MSN 0001. The SB-1 is Sikorsky’s entry into the Pentagon’s Future Vertical Lift (FVL) competition, a program that ultimately could result in deliveries of as many as 4,000 aircraft by 2030 under a contract potentially worth $100 billion and including significant foreign military sales.

First flight was anticipated by the end of this summer, but it appears that will now slip somewhat as it took Sikorsky longer than anticipated to work through a variety of technical issues, including main rotor blades and fashioning solutions to complex transmission issues related to power distribution between the main rotors and the thruster. 

The SB-1 uses the same technology Sikorsky developed for its X2 and S-97 demonstration aircraft. A second S-97 recently resumed test flying after the first aircraft was substantially damaged during a hard landing a year ago at Sikorsky’s West Palm Beach, Florida test facility.

The SB-1 is slated to compete against Bell’s V-280 third-generation tiltrotor. It features an all-composite fuselage with seating for 12 fully kitted troops and a crew of four, a rigid coaxial main rotor system, an aft thruster with a clutch, and full fly-by-wire flight controls.

The SB-1 will initially be powered by a pair of Honeywell T-55 engines but will later be upgraded to the winner of the Future Affordable Turbine Engine (FATE) competition. The aircraft is expected to have a cruising speed of 250 knots.