Tilt-wing aircraft traces beginnings to 1954

  • Published
  • By Master Sgt. Jeff Michalke
  • 16th SOW Wing History Office
While the CV-22 platform may seem to some like a fairly recent flying concept, the idea of a rotor driven aircraft that could vector its thrust surfaced as far back as the 1950s.

In 1951, Bell Helicopter began the XV-3 development under a joint Army-Air Force program. This design resembled more of a helicopter and was small in size. The XV-3 first flew in 1955 but was eventually abandoned in 1966. However, not only were tilting rotors conceived and experimented with, but also the idea of tilting the entire wing.

In early 1954, the Hiller Aircraft Corporation envisioned a tilt-wing aircraft that it proposed to both the Army and Air Force as a helicopter alternative.

Design work started in 1955 by Stanley Hiller Jr. and the Hiller Aircraft Corporation eventually received a manufacturing contract and funding from the Air Force to build the tilt-wing aircraft.

Designated the X-18 in October 1957, the company unveiled on Dec. 8, 1958, the only X-18 ever produced, the Propelloplan. This sixteen-and-a-half ton tilt-wing aircraft was capable of conventional and vertical takeoffs and landings.

On Nov. 24, 1959, the X-18 conducted its first flight at Edwards Air Force Base, Calif. Testing of the X-18 continued until 1964 when the program was eventually cancelled. The X-18 concept did prove to be successful, and the lessons learned were used to create the Chance-Vought XC-142A.

The tilt-wing XC-142A was an experimental aircraft designed to investigate the operational suitability of vertical/short takeoff and landing transports. Such an aircraft would permit rapid movement of troops and supplies into unprepared areas under all-weather conditions.

An XC-142A first flew conventionally on Sept. 29, 1964, and on Jan. 11, 1965, it completed its first transitional flight by taking off vertically, changing to forward flight and finally landing vertically.

The engines were linked together, unlike the X-18, so that a single engine could turn all four propellers and the tail rotor. In tests, the XC-142A was flown from airspeeds of 35 mph backward to 400 mph forward. The five XC-142As were tested extensively by the Army, Navy, Air Force and NASA. The only existing aircraft is on display at the National Museum of the Air Force at Wright-Patterson AFB, Ohio. The military never gave up on the concept of the tilt-rotor design, and its persistence resulted in the development of the CV-22. So as you look overhead observing the 8th Special Operation Squadron flying this magnificent piece of aviation machinery, remember it all started more than 50 years ago.