Sikorsky and Boeing’s joint multirole technology demonstrator for the U.S. Army, the SB>1 Defiant. Image courtesy of the U.S. Army
In preparation for first flight later this year, Sikorsky registered the SB-1 Defiant with the FAA, which gave the experimental prototype the designation S-100.
An FAA registry certificate was issued Aug. 2 for the coaxial-rotor Defiant, which is based on the smaller S-97 Raider that has already flown. Sikorsky confirmed to R&WI the aircraft registration was the Defiant, though it will retain the SB-1 designation in common parlance.
“Yes, the registry application for S-100 is referring to the Sikorsky-Boeing SB>1 DEFIANT,” a company spokesperson said in a statement. “Our team is following the FAA’s process for how they formally designate experimental aircraft; however, we will continue to use SB>1 DEFIANT when describing our aircraft asset.”
The FAA registry lists the S-100 as a rotorcraft driven by a turbo-shaft engine of unknown manufacture. It is also of an “unknown” classification, according to FAA records. Sikorsky Aircraft Corp. of West Palm Beach, Fla., now owned by Lockheed Martin, is the registered owner.
The FAA also issued Defiant the registration number N100FV, which mirrors the U.S. Army’s Future Vertical Lift (FVL) program in which the aircraft is enrolled as a technology demonstrator.
SB-1 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.
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.
Both S-97 prototypes, designated S-97A by the FAA but carrying registration numbers N971SK and N972SK, carry experimental classification.
Defiant, a third-generation X2 aircraft, is scheduled to fly in 2018 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.
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.”