Sikorsky H-34 (factory designation: Model 58) was designed using experience gathered while designing, manufacturing and use of Sikorsky H-19 (Model 55). In both of those machines the engine was installed in the front of the hull, and the cockpit is above the engine. Such solution makes the helicopter less sensitive against center of gravity shifts (which in turn allows for more elastic applicacion of the machine) and additionally facilitates access to and maintenace of the engine.
The beginnings of Model 58 in the early fifties were not so optimistic: in the competition held by US Army it lost to the Vertol H-21, in US Navy's competition it lost to Bell HSL-1 and Marines wanted to buy another Sikorsky's design, the Model 56 (H-37 Mojave). Later it turned out that Vertol has problems satisfying US Army's demand for the H-21, Bell HSL-1 is not suitable for sonar work because of excessive airframe vibration, and Model 56 has development problems and is not yet ready. In this situation all three services ordered the Model 58. US Army used it as H-34 Choctaw, US Navy - as HSS Seabat and the Marines - as HUS Seahorse. In 1962 the designations of all US military aircraft were unified, and from then on the helicopter's variants were known as CH-34, SH-34 and UH-34 respectively.
It might be interesting to note, that during the visit of Nikita Khrushchev, the first secretary of the Communist Party of the Soviet Union, in 1959 he used the presidential VH-34A (VIP version) helicopter and liked it so much, that he ordered two machines, which were then delivered in 1960 and used in Soviet Union.
Because of the French experiences with Model 58 and their reports of it's vulnerability to ground fire, and also because of logistical issues, US Army decided not to send their H-34's to Vietnam, using H-21, the "flying bananas" insted. The Marines, having no other choice, used their UH-34 (also known as "Huss") in Vietnam and didn't confirm the bad experiences of the French. First UH-34's arrived in Vietnam with HMM-362 in Soc Trang as part of Operation Shufly in mid-April 1962. Their objective was to provide tactical helicopter mobility to Army of Republic of Vietnam (ARVN) troops. This operation helped develop techniques and tactics later used throughout the conflict and even after it ended.
The UH-34 were liked by the crews and constituted the backbone of Marines' helicopter fleet, even after the acquired their own version of the famous Huey - the UH-1E. In March 1965 the CH-46A begun to replace the UH-34, but series of crashes of the CH-46 led to their grounding, and the UH-34 had to do the job until the problems of CH-46 were solved. The last UH-34 was withdrawn from service in August 1969 by HMM-362. Surplus "Husses" were transferred to the armed forces of Republic of Vietnam, which successfully used them.
|Length (fuselage):||14 170 mm|
|Rotor diameter:||17 060 mm|
|Empty weight:||3583 kg|
|Maximum weight:||6360 kg|
|Propulsion:||One 1137 kW Wright R1820-84B Cyclone 9 cylinder air-cooled radial engine|
|Armament:||None, or one M60 7,62mm machine gun in cargo bay door|
|Max speed:||198 km/h|