X-Wing: A Low Disc-Loading V/STOL for the Navy 851772

The X-Wing concept employs a single lifting system for all modes of flight. The lifting system is comprised of four very rigid, circulation control wings with blowing for lift modulation and control. For hover and low speed flight, the wings rotate such as the rotor of a helicopter. For high speed flight, the wings are stopped in an “X” configuration across the fuselage - from which the name of the concept is derived - with two forward-swept wings and two aft-swept wings.

Such a vehicle is also envisioned to have an integrated gas turbine propulsive system for all flight modes. At low speeds, the gas generators) would drive a shaft to turn the wings and the circulation control compressor as well as a set of propulsive fans. For high-speed flight, the shaft would drive only the compressor and accessories as the fans propel the vehicle.

The X-Wing concept has been underdevelopment for over 15 years. Sikorsky Aircraft Division began the most recent phase of concept development in 1983 to design, fabricate, and flight test a full-scale X-Wing rotor/wing on the NASA/Army Rotor Systems Research Aircraft (RSRA). To date, detail design is complete, hardware fabrication and system testing are underway, and the first test flight is planned for 1986, The X-Wing promises to be the first VTOL (vertical takeoff and landing) concept to combine efficient low-downwash-velocity hover characteristics with efficient high-subsonic speed cruise capability. These attributes contribute to the potential Navy missions of such an aircraft and extend the implications of the X-Wing technology development beyond the present X-Wing program.

Two aircraft designs have been developed. The first design is an X-Wing concept demonstrator vehicle for the 1990 time period that makes maximum use of the available RSRA/X-Wing hardware. The second design is an operational demonstrator for a production aircraft with an initial operational capability (IOC) date of 2000.