Sikorsky S-72 RSRA

The RSRA ( Rotor Systems Research Aircraft ) was developed by Sikorsky for NASA and the Army. Configured with rotor, wings and auxiliary jets, the RSRA allows testing of new rotor concepts at speeds up to 300 knots. It can fly like a helicopter with a wing and jets, or as a fixed-wing aircraft without a rotor.

The RSRA was a unique pure research aircraft developed to fill the void between design analysis, wind tunnel testing, and flight results of rotor aircraft. The joint NASA/Army project began in December of 1970, first flight on October 12, 1976 with the first of two aircraft arriving from Sikorsky to NASA on February 11, 1979. The aircraft was designed to investigate the concepts involved with stopping the main rotor in flight, with the large blades then providing aerodynamic lift assistance to the stubby conventional wings extending from the lower fuselage. This concept gave the aircraft the vertical flight stability of a helicopter, and the horizontal cruise capability of a conventional aircraft.

This machine incorporates a world's certified helicopter crew-ejection system where the blades are severed in sequence and rockets pull the crew to safety.

Another role for the RSRA was as the flying test bed for the Sikorsky X-Wing. This revolutionary rotor was designed to allow an aircraft to take off and and land vertically, yet fly like a conventional airplane with the rotor stopped.