The RSRA was developed under a joint NASA/Army program in the 1970s to test developmental propulsion and rotor systems. Two aircraft were built by Sikorsky: 72001 (tail 545 / N740NA) and 72002 (tail 546 / N741NA). Both RSRA aircraft could fly in 3 different configurations – as a pure helicopter, a compound helicopter fitted with wings and TF34 (S-3A Viking) engines on fuselage mounted pylons, or a fixed wing aircraft with the rotor removed.
The RSRA was a first in many respects, and featured a crew extraction system that when activated, used explosives to sever the rotor blades from the hub allowing for crew members to be jettisoned from the aircraft via rockets.
The X-Wing:
Aircraft S/N 72002 was later modified by Sikorsky to test a new “X-Wing” rotor system that could be stopped in flight and act as a wing. This newly modified 72002 became 72003 and was known as the RSRA/X-Wing. Both 72002 and 72003 wore tail N741NA.
Aircraft 72003 completed several test flights after its conversion without the new X-Wing rotor system installed, but due to budgetary constraints, the aircraft never flew with the X-Wing rotor.