The Sikorsky CH-54 Tarhe is an American twin-engine heavy-lift helicopter designed by Sikorsky Aircraft for the United States Army. It is named after Tarhe, an 18th-century chief of the Wyandot Indian tribe whose nickname was "The Crane". The civilian version is the Sikorsky S-64 Skycrane.
Development
Work on what would become the CH-54 can be traced back to Sikorsky's earlier activities with "sky-crane" helicopters, particularly the piston-engined Sikorsky S-60 of the late 1950s. Following the end of the Korean War, the United States Army sought to procure a successor to the Sikorsky CH-37 Mojave, an early piston-engined heavy lift helicopter; being aware of this need, Sikorsky were keen to fulfill it. The company was already working on the Sikorsky S-64 Skycrane, a civil-orientated heavy lift rotorcraft that was designed specifically for the purpose of carrying large payloads externally; the development of a military-configured derivative was viewed as a natural option. While Sikorsky were quick to recognise the advantages of adopting turboshaft propulsion, there were no suitable engines of that type initially available, thus it had to work with the American engine manufacturer Pratt and Whitney to modify their JT12 turbojet to produce one. One innovative feature for any helicopter of the era was the incorporation of an automatic flight control system, effectively a fly-by-wire arrangement. This feature enabled the aft-facing crew member to control the rotorcraft's pitch, roll, and yaw with 10% control authority, along with an altitude-hold function; it was also praised for being relatively easy to fly under instrument flight rules (IFR). Considerable attention was paid to the fuselage's design, particularly to minimising weight and maintenance requirements. The landing gear was designed to kneel to make loading easier as well as to ease operations from sloped surfaces. From the onset, Sikorsky sought to enable the type to carry as diverse a range of cargoes as possible, leading to the incorporation of fitting for the carriage of barges and of a specially designed multipurpose "people pod" that was suited for use for personnel transport, paratroop operations, and even as a mobile hospital or mobile command post. On 9 May 1962, the first of three prototypes performed its maiden flight. It was subsequently tested by the US Army at Fort Benning while the other two underwent an evaluation in West Germany. During June 1963, it was announced that the US Army had placed an order for an initial six helicopters, designating it as the CH-54A; the first of these was officially accepted on 30 June 1963. Following a relatively brief period of testing and evaluation, the CH-54 was quickly put into active use in Vietnam. Early on, the type had demonstrated itself to possess unrivalled performance in some aspects. As of 2014, it continues to hold the helicopter record for highest altitude in level flight at 11,000 m (36,000 ft), which it set in 1971, as well at the fastest climb to 3,000, 6,000, and 9,000 m (10,000, 20,000, and 30,000 ft). On 20 April 1965, a CH-54A equipped with a people pod lifted 90 people, comprising its crew of 3 and 87 combat-equipped troops; this was the largest number of people to be lifted by a single helicopter at that time.
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