Hughes OH-6 Cayuse

Four bladed light observation helicopter

Hughes OH 6A Cayuse
photo: Steve Lynes

The Hughes OH-6 Cayuse is a single-engine helicopter developed by Hughes Helicopter fitted with a four-bladed main rotor. It is used for personnel transport, escort and attack operations, and as a light observation helicopter. It was produced since 1965 and has been in service with its primary user, the United States Army.

Manufacturer:
McDonnell Douglas
Country:
United States
Manufactured:
1965 to: Present
ICAO:
OH6A
Price:
US$.02 million (1966)

Specifications

Avionics:
Engine:
1x Allison T63-A-5A
turboshaft
Power:
317 horsepower
Max Cruise Speed:
130 knots
241 Km/h
Approach Speed (Vref):
Travel range:
330 Nautical Miles
611 Kilometers
Fuel Economy:
Service Ceiling:
15,800 feet
Rate of Climb:
2067 feet / minute
10.50metre / second
Take Off Distance:
Landing Distance:
Max Take Off Weight:
1,610 Kg
3,549 lbs
Max Landing Weight:
1,440 Kg
3,175 lbs
Max Payload:
713 Kg
1,572 lbs
Fuel Tank Capacity:
62 gallon
233 litre
Baggage Volume:
Seats - Economy / General:
2 seats
Seats - Business Class:
Seats - First Class:
Cabin Height:
1.5 metre - 4.92 feet
Cabin Width:
1.3 metre - 4.27 feet
Cabin Length:
2.4 metre - 7.87 feet
Exterior Length:
9.4 metre - 30.84 feet
Tail height:
Fuselage Diameter:
1.45 metre - 4.76 feet
Wing Span / Rotor Diameter:
8.03 metre - 26.34 feet
Wing Tips:
no winglets
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Description

On October 14, 1960, a request for proposals (RFP) for Technical Specification 153 from the United States Navy Bureau of Weapons was issued for a Light Observation Helicopter (LOH) that can perform several roles such as personnel transport, escort and attack missions, casualty evacuation and observation. In January 1961, twelve aircraft manufacturers had responded, and Hughes Tool Co. Aircraft Division presented the Model 369.

On February 27, 1963, the Model 369 conducted its maiden flight. In 1962, the original designation YHO-6A was changed to YOH-6A when the United States Department of Defense made a Joint Electronics Type Designation System for all aircraft. Five aircraft were built, powered by an Allison T63-A-5A rated at 252 shaft horsepower. These aircraft were sent to the United States Army at Fort Rucker, Alabama to contest in opposition to the other ten prototype aircraft of Bell and Fairchild-Hiller. Hughes won against other competing companies and received a contract from the Army for production to start in May 1965. 714 initial orders were placed, then afterward raised to 1,300 with a possibility to increase to 114 more. In 1966, the OH-6A entered service.

The OH-6A has an external length of 9.4 meters, a height of 2.47 meters to the top of the rotor hub, and a diameter of 1.45 meters. It can seat two passengers or four on the floor with rear seats folded or removed.

A single Allison T63-A-5A turboshaft powered the rotorcraft. It has a maximum thrust of 317 shaft horsepower or 252.2 shaft horsepower for takeoff and 214.5 shaft horsepower for maximum continuous. The main rotor diameter is 8.03 meters and the main rotor area is 50.60 square meters. It can fly up to 15,800 feet and can climb up to 2,067 feet per minute. The maximum cruise speed at sea level is 130 knots and the travel range is 330 nautical miles at 5,000 feet. The maximum takeoff and landing weights are 1610 kg and 1440 kg respectively.