Kaman K-225 was an experimental helicopter developed by Kaman Aircraft. One was modified to become the world's first gas turbine-powered helicopter.
Design and development [ edit ]
K-125 was Charles Kaman's first helicopter, which utilized intermeshing rotors and Kaman's patented servo-flap stability control. The K-125 first flew on 15 January 1947. 
The K-190 and K-225 were an improved versions of the K-125, which first flew in April and July 1949 respectively. The U.S. Navy bought two and the Coast Guard one for $25,000 each. The United States Air Force evaluated one K-225 with the designation YH-22.
A modified K-225 equipped with a
Boeing 502 (YT50) turboshaft engine became the world's first gas turbine- powered helicopter in December 1951. This aircraft is now at the  Smithsonian Institution in Washington, D.C.
Variants [ edit ]
improved prototype version of K-125 and licensed in April 1949
improved prototype version of K-125 (and K-190) and licensed in July 1949
United States Aircraft designation for one K-225 bought for evaluation.
United States Navy designation for two K-225s bought for evaluation.
Designation for one K-225 evaluated by the United States Coast Guard
Specifications (K-225) [ edit ]
Data from  
Length: 22 ft 5 in (6.83 m)
Height: 11 ft 0 in (3.35 m)
Empty weight: 1,799 lb (816 kg)
Gross weight: 2,703 lb (1,226 kg)
Powerplant: 1 × Lycoming O-435-2 6-cyl. air-cooled horizontally opposed piston engine, 225 hp (168 kW)
Main rotor diameter: 2× 38 ft 0 in (11.58 m)
Maximum speed: 73 mph (117 km/h; 63 kn)
See also [ edit ]
Aircraft of comparable role, configuration and era
References [ edit ]
External links [ edit ]
helicopter designations pre-1962
Helicopter, Trainer pre-1948
Helicopter, Trainer 1948-1962
Helicopter, Transport 1944-1962
Helicopter, Utility pre-1949
Helicopter, Utility 1950-1962