Engineering:Kaman K-225
| K-225 | |
|---|---|
_(18160147725).jpg)
| |
| XHTK-1 modified with a Boeing 502 (YT50) turboshaft engine | |
| Role | Experimental helicopter |
| National origin | United States |
| Manufacturer | Kaman Aircraft |
| First flight | 15 January 1947 (K-125) |
| Status | Retired |
| Primary users | United States Navy United States Coast Guard |
| Number built | 7 |
The Kaman K-225 is an American experimental helicopter developed by Kaman Aircraft. One example was modified to become the world's first gas turbine-powered helicopter.
Design and development
The K-125 was Charles Kaman's first helicopter, which utilized intermeshing rotors and Kaman's patented servo-flap stability control.[1] 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 first gas turbine-powered helicopter in December 1951.[2] This aircraft is now at the Smithsonian Institution in Washington, D.C.
A standard K-225 is preserved in the New England Air Museum at Windsor Locks Connecticut.
In 1953, the Turkish Army purchased one Kaman K-225 helicopter and a K-225 was the first helicopter flown in Turkey.[3]
Variants
- K-125
- first two-seat prototype with 125 hp (93 kW) Lycoming O-390-3 engine and moulded plywood fuselage and bubble canopy.
- K-190
- improved prototype with 190 hp (140 kW) Lycoming engine, marketed as an open cockpit crop-duster, certified in April 1949[4]
- K-190A
- open frame three-seat helicopter, powered by a 175 hp (130 kW) Lycoming O-435-C engine. Type certified on April 15, 1949.[5]
- K-190B
- four-seat version.
- K-225
- improved model, powered by a 225 hp (168 kW) Lycoming O-435-A2 engine, certified on September 16, 1949.[5]
- K-5
- designation for K-225 with Boeing T50-BO-2 model 502 engine.
- YH-22
- United States Air Force designation for one K-225 bought for evaluation.
Specifications (K-225)
General characteristics
- Crew: two
- 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)
Performance
- Maximum speed: 73 mph (117 km/h, 63 kn)
See also
Related development
Aircraft of comparable role, configuration and era
References
Notes
- ↑ "Hall of Fame/Inventor Profile: Charles Kaman"
- ↑ Boeing Model 502 Gas Turbine Engine
- ↑ "Turkish Kaman 225". https://twitter.com/Alfred_Bubi/status/1187078039714353152.
- ↑ "Kaman K-225" (in en-US). https://airandspace.si.edu/collection-objects/kaman-k-225/nasm_A19571016000.
- ↑ 5.0 5.1 Federal Aviation Administration (September 26, 1950). "Helicopter Specification No. 1H1". faa.gov. https://rgl.faa.gov/Regulatory_and_Guidance_Library/rgMakeModel.nsf/0/3e60365669cd4d2785256715006b5dcc/$FILE/1h1.PDF.
- ↑ Eckland, K.O. (2009-03-07). "American Airplane Ka-Ku". usa: Aerofiles.com. http://aerofiles.com/_k.html.
- ↑ Kaman K-225 , Smithsonian National Air and Space Museum, cit. 28. 1. 2013
Bibliography
- "Hall of Fame/Inventor Profile: Charles Kaman". National Inventors Hall of Fame. http://www.invent.org/hall_of_fame/190.html.
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