Defiant is a further extrapolation of Sikorsky's X2 technology demonstrator, which pioneered its unique configuration. The S-97 Raider, an armed reconnaissance coaxial rotor compound helicopter that the company also derived from the X2 concept and has helped further inform the development of the SB>1, has been flying for years now and two prototypes are currently in testing. Lockheed Martin has since purchased Sikorsky, but it continues to operate under that name and as a separate business unit.

The Defiant and the Valor are set to go head to head as part of the Army's Joint Multi-Role (JMR) technology demonstration program. The service had hoped to begin these flight tests in December 2017, but pushed its timeline back due to the delays with the SB>1.

The Army plans to use the results from JMR to help better understand and define the Future Vertical Lift (FVL) program requirements. The SB>1 and V-280, or refined versions of these designs, will be heading for a brawl over the "medium" portion of that project, which aims to replace hundreds of UH-60 Black Hawks and AH-64 Apaches. The Sikorsky-Boeing team plans to pitch the Defiant as a successor to the Black Hawks and has shown a companion gunship design as the Apache replacement.