Hughes 369 (OH 6/OH 6A) Cayuse

Hughes Tool Company

First Flight: February 27. 1963

Data from Jane’s Encyclopedia of Aviation except for Engine, which is taken from the exhibit aircraft name plate.

In 1960 the U. S. Department of Defense issued Technical Specification 153 for a LOH (Light Observation Helicopter) capable of performing a variety of tasks that ordinarily would require the deployment of different types of aircraft. These tasks included personnel or cargo, transport, light ground attack, and casualty evacuation, in addition to observation and photographic reconnaissance.

The Hughes Model 369, based on the Model 269, was given the revised military designation OH‑6 in July 1962. On 27 February 1963 the first OH‑6 (N9696F) made its maiden flight, and U. S. Army trials began at Ft. Rucker, Alabama the following November.

Because of its semi­-monocoque construction, aerodynamic shape and compactness (it was nicknamed the "flying egg' because of its shape)  the OH‑6A was easy to build, fly and maintain, and could carry 2 pilots and 4 fully equipped troops or 950 lbs. of cargo internally. The maximum external sling load is 1,350 lbs. Avionics included ADF, a track indicator, and VHF and LIHF transceivers. A wide choice of weapons was available. Kit type ordnance, which is attached to the cabin sides, included an XM‑75 grenade launcher or an XM‑27 or XM‑27‑E‑1 machine gun pod with 2000 rounds of ammunition. The gun pods could be pivoted through 90 degrees to fire forward or at intermediate downward angles.

Despite all these features, the selection of the OH‑6A Cayuse as winner of the U. S. Army's LOH competition on 26 May 1965 was based chiefly on its lower cost. Initial production orders covered 714 helicopters. This quantity later was increased to 1,300 with an option for an additional 114. Delivery started in September 1966 and was due for completion by early 1969, with an anticipated eventual requirement involving more than 4000 aircraft. But cost over‑runs, along with production delays, caused the U. S. Army to reopen the design competition in 1967, with only 1434 of the anticipated 4000 aircraft on order. The last of these were delivered in August 1970. The re‑competition was won by Bell's OH‑58 Kiowa, a spin‑off of the well‑known Bell Jet‑Ranger.

The Cayuse set 23 world records in the 1960s, including a 2,213 mile non‑stop flight from California to Florida, a sustained altitude record of 28,218 feet, and a speed record of 172 mph.

Aircraft Specifications

Rotor Diameter: 
26 ft. 4 in.
Fuselage Length: 
23 ft.
Maximum Speed: 
172 mph
Cruise Speed: 
150 mph
Height: 
8 ft. 2 in.
Gross Weight: 
2,700 lbs.
Engine: 
317 shp Allison 250 C-18