The Kaman K-225 is an American experimental

helicopter A helicopter is a type of rotorcraft in which lift and thrust are supplied by horizontally spinning rotors. This allows the helicopter to take off and land vertically, to hover, and to fly forward, backward and laterally. These attributes ...

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 h ...

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

gas turbine A gas turbine, also called a combustion turbine, is a type of continuous flow internal combustion engine. The main parts common to all gas turbine engines form the power-producing part (known as the gas generator or core) and are, in the directio ...

-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 and education and research centers, the largest such complex in the world, created by the U.S. government "for the increase and diffusion of knowledge". Founded ...

in Washington, D.C. A standard K-225 is preserved in the

New England Air Museum The New England Air Museum (NEAM) is an American aerospace museum located adjacent to Bradley International Airport in Windsor Locks, Connecticut. The museum consists of three display hangars with additional storage and restoration hangars. Its co ...

at Windsor Locks

Connecticut Connecticut () is the southernmost state in the New England region of the Northeastern United States. It is bordered by Rhode Island to the east, Massachusetts to the north, New York to the west, and Long Island Sound to the south. Its capita ...

. 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, certified in April 1949 ;K-190A :open frame three-seat helicopter, powered by a

Lycoming O-435 The Lycoming O-435 is an American six-cylinder, horizontally opposed fixed-wing aircraft and helicopter engine made by Lycoming Engines Lycoming Engines is a major American manufacturer of aircraft engines. With a factory in Williamspor ...

-C engine. Type certified on April 15, 1949. ;K-190B :four-seat version. ;K-225 :improved model, powered by a

-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. Based on Boeing's earlier Model 500 gas generator, the T50's main application was in the QH-50 DASH helicopter drone of the 1950s. An up-rated versi ...

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

United States Air Force The United States Air Force (USAF) is the Aerial warfare, air military branch, service branch of the United States Armed Forces, and is one of the eight uniformed services of the United States. Originally created on 1 August 1907, as a part ...

designation for one K-225 bought for evaluation.

Specifications (K-225)

References

Notes

Bibliography