Friends of The Helicopter Museum

Rolls-Royce Allison 250

Rolls Royce Allison Model 250/T63

Rolls-Royce has donated an early example of one of the world's most widely-used turbine aircraft engines, the Allison Model 250/T63 turboshaft, to The Helicopter Museum. It is now on display following its arrival in early April 2002.

The initial development contract for the Model 250/T63 engine (civil/military versions) was placed by the US Department of Defense in June 1958 and its first flight was in a Bell UH-13R in January 1961. Production deliveries began in 1965 and the T63 entered US Army service in a Hughes OH-6A Cayuse in 1966 (a 1968 OH-6A is in the Museum collection, see below) when the Allison Engine Company signed a Model 250 distribution agreement with Rolls-Royce.
Hughes OH-6A Hughes OH-6A Nose
Having served with the US Army during the Vietnam War this Hughes OH-6A, Cayuse, four seat light observation helicopter, c/n 67-16506, built in Culver City in 1968 and powered by one 317 shp Allison T63-A-5A turboshaft, is now on display in The Helicopter Museum collection.
The Model 250 turboprop and turboshaft engines have continued to improve, with increasingly powerful variants over the last 40 years, and development is being maintained. More than 29,000 engines have been delivered and over 16,000 are in service world-wide. The Museum's example is a 317 shp T63-A-700 turboshaft, as used to power the Bell OH-58A Kiowa in 1968.

Later, in 1975, U.S. Army Bell OH-58C Kiowas were fitted with an uprated 420 shp Allison T63-A-720 engine. In 2003/04, serving in Iraq, OH-58D Kiowa Warriors were powered by 650 shp Model 250-C30R engines. The Model 250 continues to find new applications including the Russian Kamov Ka-226, a direct descendant of the Museum's Ka-26 helicopter. Nearly 30,000 Model 250 engines had been produced by the end of 2006 with approximately 16,000 remaining in service. After many years of close co-operation the Allison Engine Company was acquired by Rolls-Royce in March 1995.

Allison Model 250

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