Boeing/Hughes
OH-6 Cayuse

The Hughes OH-6 Cayuse is a single-engine light helicopter designed and produced by the American aerospace company Hughes Helicopters. Its formal name is derived from the Cayuse people, while its "Loach" nickname comes from the acronym for the Light Observation Helicopter (LOH) program under which it was procured.

During 1960, the United States Army issued Technical Specification 153 for a Light Observation Helicopter (LOH) capable of fulfilling various roles on the battlefield, including personnel transport, escort, casualty evacuation, observation, and attack missions. These would be used to replace its fleet of Bell H-13 Sioux, a compact first generation rotorcraft. Twelve companies opted to participate in the competition, Hughes Tool Company's Aircraft Division being one of them, submitted the Model 369 as its response. Two of these designs, those submitted by Fairchild-Hiller and Bell, were selected as finalists by the Army-Navy design competition board. However, the U.S. Army subsequently chose to include Hughes's Model 369 for further consideration as well.

During 1966, the OH-1 entered service with the U.S. Army. Its first overseas deployment, as well as into frontline combat, was the Vietnam War. The pilots dubbed the new helicopter Loach, a word created by pronunciation of the acronym of the program that spawned the aircraft, LOH (light observation helicopter). During 1964, the U.S. Department of Defense issued a memorandum directing that all U.S. Army fixed-wing aircraft be transferred to the U.S. Air Force, while the U.S. Army transitioned to solely operating rotor-wing aircraft. Accordingly, the U.S. Army's fixed-wing airplane, the Cessna O-1 Bird Dog, which was utilized for artillery observation and reconnaissance flights, would be replaced by the incoming OH-6AWiki Link