The Kaman K-225 is an American experimental

helicopter A helicopter is a type of rotorcraft in which Lift (force), lift and thrust are supplied by horizontally spinning Helicopter rotor, rotors. This allows the helicopter to VTOL, take off and land vertically, to hover (helicopter), hover, and ...

developed by

Kaman Aircraft Kaman Corporation is an American aerospace company, with headquarters in Bloomfield, Connecticut. It was founded in 1945 by Charles Kaman. During the first ten years the company operated exclusively as a designer and manufacturer of several ...

. One example was modified to become the world's first

gas turbine A gas turbine or gas turbine engine is a type of Internal combustion engine#Continuous combustion, continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas gene ...

-powered helicopter.

Design and development

The K-125 was Charles Kaman's first

, which utilized intermeshing rotors and Kaman's patented servo-flap stability control."Hall of Fame/Inventor Profile: Charles Kaman" 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. This aircraft is now at the

Smithsonian Institution The Smithsonian Institution ( ), or simply the Smithsonian, is a group of museums, Education center, education and Research institute, research centers, created by the Federal government of the United States, U.S. government "for the increase a ...

in Washington, D.C. A standard K-225 is preserved in the New England Air Museum at Windsor Locks

Connecticut Connecticut ( ) is a U.S. state, state in the New England region of the Northeastern United States. It borders Rhode Island to the east, Massachusetts to the north, New York (state), New York to the west, and Long Island Sound to the south. ...

. In 1953, the Turkish Army purchased one Kaman K-225 helicopter and a K-225 was the first helicopter flown in Turkey.

Variants

Kaman K-225 N401A New England Air Msm 09

;K-125 :first two-seat prototype with Lycoming O-390-3 engine and moulded plywood fuselage and bubble canopy. ;K-190 :improved prototype with Lycoming engine, marketed as an open cockpit crop-duster, certified in April 1949 ;K-190A :open frame three-seat helicopter, powered by a Lycoming O-435-C engine. Type certified on April 15, 1949. ;K-190B :four-seat version. ;K-225 :improved model, powered by a Lycoming O-435-A2 engine, certified on September 16, 1949. ;K-5 :designation for K-225 with

Boeing T50 The Boeing T50 (company designation Model 502) was a small turboshaft engine produced by Boeing. It was the first turboshaft engine to ever power a helicopter: a modified Kaman K-225 in 1951. Based on Boeing's earlier Model 500 gas generator, t ...

-BO-2 model 502 engine. ;YH-22 :

United States Air Force The United States Air Force (USAF) is the Air force, air service branch of the United States Department of Defense. It is one of the six United States Armed Forces and one of the eight uniformed services of the United States. Tracing its ori ...

designation for one K-225 bought for evaluation.

Specifications (K-225)

References

Notes

Bibliography