Development
The Westminster was the first tangible result of efforts that Westland Aircraft had been making throughout the 1950s to produce a gas-turbine-powered heavy-lift helicopter. Projects ranged up to the remarkable W.90, a 450-seat troopship with three Armstrong Siddeley Sapphire turbojets mounted on its rotor-tips. [1]
In 1954, Westland investigated licensed manufacture of the Sikorsky S-56 for the civil market with turboshaft power. The company sought Ministry of Supply support for the proposal, but this was not forthcoming. In June 1958, Westland obtained an extension to their licence agreement with Sikorsky to cover the five bladed main-rotor, gearbox, tail-rotor, transmission and control systems of the S-56. Faced with continuing government indifference, Westland decided to press ahead with a private-venture design for a heavy-lift transport, built around the S-56 systems but powered by a pair of Napier Eland turboshafts. At the time, Westland was heavily committed to development of the Wessex (a turbine powered Sikorsky S-58) and the Westminster project had to be run on a shoestring. [2]
Two variants were initially envisioned: a 40-seat, short-range civil transport and a flying crane with a 15,000 lb (6.8 t) capacity. In March 1956, Westland decided to build the first prototype as a flying test rig with a tubular steel space frame in place of the main fuselage; cockpit power-train and undercarriage attached to this. With economy a priority, off-the-shelf components were used as far as possible, with donors such as the Westland Whirlwind helicopter and the Bristol Freighter aeroplane. This prototype was completed in February 1958; after the usual static and systems testing, engine runs and nearly 20 hours of "tied-down" engine testing, the first flight took place on 15 June. [3] Flight testing showed up significant vibration. As a result, a number of changes were made in the design of the second prototype, including replacement of the main-rotor with the six-blade unit from the Sikorsky S-64 Skycrane. Once the statutory ten hours had been flown, this first Westminster was registered G-APLE and work started on constructing the second prototype.
Around this time, the Admiralty began to feel that the Westminster project was delaying development of the Wessex for the Royal Navy. Although this was mere fancy, it boded ill for the larger aircraft. [4] For the moment, work continued; G-APLE's space frame was covered with a streamlined shell of wood covered with Terylene fabric and the rotor was replaced with an experimental six-blade unit. It first flew in this form on 12 June 1960. [5]
The second prototype, registered G-APTX [4] flew on 5 September 1959 and flight testing continued, but the British helicopter industry was in a state of flux; the entire industry was being consolidated under Westland with the company's purchase of the helicopter divisions of Saunders-Roe, Bristol and Fairey. In the process, Westland acquired two potential rivals to the Westminster: the projected civil Bristol 194 development of the military Bristol Type 192 Belvedere and the Fairey Rotodyne (a gyrodyne design). Rationalisation was necessary and since the Rotodyne was already flying and government funded, work on the Westminster ceased in September 1960. [4]
The two aircraft were broken up; the components supplied by Sikorsky were stripped out and shipped back to the US to avoid paying import duty and the airframes were sold as scrap. [4]
Westland Aircraft was a British aircraft manufacturer located in Yeovil, Somerset. Formed as a separate company by separation from Petters Limited just before the start of the Second World War, Westland had been building aircraft since 1915. During the war the company produced a number of generally unsuccessful designs, but their Lysander would serve as an important liaison aircraft with the Royal Air Force. After the war the company focused on helicopters, and was merged with several other British firms to create Westland Helicopters in 1961.
Westland Helicopters was a British aircraft manufacturer. Originally Westland Aircraft, the company focused on helicopters after the Second World War. It was amalgamated with several other British firms in 1960 and 1961.
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The Sikorsky CH-37 Mojave is an American large heavy-lift military helicopter of the 1950s. It entered service as the HR2S-1 Deuce with USMC in 1956, and as the H-37A Mojave with the U.S. Army that same year. In the early 1960s the designation was standardized to CH-37 for both services, with the HR2S-1 redesignated as CH-37C specifically.
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The Bristol Type 192 Belvedere is a British twin-engine, tandem rotor military helicopter built by the Bristol Aeroplane Company. It was designed by Raoul Hafner for a variety of transport roles including troop transport, supply dropping and casualty evacuation. It was operated by the Royal Air Force (RAF) from 1961 to 1969. The Belvedere was Britain's only tandem rotor helicopter to enter production, and one of the few not built by Piasecki or Boeing.
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A gyrodyne is a type of VTOL aircraft with a helicopter rotor-like system that is driven by its engine for takeoff and landing only, and includes one or more conventional propeller or jet engines to provide forward thrust during cruising flight. During forward flight the rotor is unpowered and free-spinning, like an autogyro, and lift is provided by a combination of the rotor and conventional wings. The gyrodyne is one of a number of similar concepts which attempt to combine helicopter-like low-speed performance with conventional fixed-wing high-speeds, including tiltrotors and tiltwings.
The Sikorsky CH-53K King Stallion is a heavy transport helicopter designed and produced by Sikorsky Aircraft. The King Stallion is an evolution of the long running CH-53 series of helicopters which has been in continuous service since 1966, and features three up-rated 7,500 shp (5,590 kW) engines, new composite rotor blades, and a wider aircraft cabin than its predecessors. It is the largest and heaviest helicopter in the U.S. military.
The Fairey Jet Gyrodyne is a British experimental compound gyroplane built by the Fairey Aviation Company that incorporated helicopter, gyrodyne and autogyro characteristics. The Jet Gyrodyne was the subject of a Ministry of Supply (MoS) research contract to gather data for the follow-up design, the Rotodyne.
The Bristol Type 173 was a British twin-engine, tandem rotor transport helicopter built by the Bristol Aeroplane Company. It was designed by Raoul Hafner as a civil transport helicopter but evoked interest from the military. It did not enter production but was developed into the Bristol Belvedere which was operated by the Royal Air Force from 1961 to 1969.
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The Napier Eland is a British turboshaft or turboprop gas-turbine engine built by Napier & Son in the early 1950s. Production of the Eland ceased in 1961 when the Napier company was taken over by Rolls-Royce.
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