[citation needed] The S-72 could be fitted with wings and General Electric TF34 turbofans to allow compound helicopter configurations to be experimentally investigated at speeds up to 300 knots (560 km/h; 350 mph).

This system, when activated, fired explosive bolts that severed the main rotor blades, escape panels were blown off the roof of the aircraft.

The joint NASA/Army project began in December 1970, first flight on October 12, 1976, with the first of two aircraft arriving from Sikorsky to NASA on February 11, 1979.

One notable test performed with the RSRA was the use of the main and tail rotor load measurement system to determine the vertical drag of the airframe.

The X-Wing was intended to be used in roles such as air-to-air and air-to-ground operations, as well as airborne early warning, search and rescue and anti-submarine warfare.

[15] In late 1983, Sikorsky received a contract to modify one S-72 RSRA into a demonstration testbed for the X-Wing rotor system.