The Ling-Temco-Vought (LTV) XC-142 is a tiltwing experimental aircraft designed to investigate the operational suitability of vertical/short takeoff and landing (V/STOL) transports.

Its service sponsors pulled out of the program one by one, and it eventually ended due to a lack of interest after demonstrating its capabilities successfully.

In 1959 the United States Army, Navy and Air Force began work on the development of a prototype V/STOL aircraft that could augment helicopters in transport-type missions.

On 27 January 1961, a series of DOD actions resulted in an agreement where all of the military services would work on the Tri-Service Assault Transport Program under the Navy's Bureau of Naval Weapons (BuWeps) leadership.

However, for the Marine Corps mission, the requirement stated that the fuel load could be reduced so that the maximum gross weight would not exceed 35,000 pounds (16,000 kg), as long as a 100-nautical-mile (190 km) radius was maintained.

Vought responded with a proposal combining engineering from their own design arm, as well as Ryan and Hiller, who had more extensive helicopter experience.

The design was initially known as the Vought-Ryan-Hiller XC-142, but when Vought became part of the Ling-Temco-Vought (LTV) conglomerate this naming was dropped.

Tests included carrier operations, simulated rescues, paratroop drops, and low-level cargo extraction.

One of the limitations found in the aircraft was an instability between wing angles of 35 and 80 degrees, encountered at extremely low altitudes.

There were also high side forces which resulted from yaw and weak propeller blade pitch angle controls.

The basic design was fairly typical for a cargo aircraft, consisting of a large boxy fuselage with a tilted rear area featuring a loading ramp.

The XC-142 was powered by four General Electric T64 turboshaft engines cross-linked on a common driveshaft, which eliminated engine-out asymmetric thrust problems during V/STOL operations, to drive four 15.5-foot (4.7 m) Hamilton Standard fiberglass propellers.