| Type 192 Belvedere | |
|---|---|
 The Bristol Type 192 Belvedere tandem rotor helicopter | |
| General information | |
| Type | Cargo helicopter |
| Manufacturer | Bristol Aeroplane Company |
| Primary user | Royal Air Force |
| Number built | 26 |
| History | |
| Introduction date | 1961 |
| First flight | 5 July 1958 |
| Retired | 1969 |
| Developed from | Bristol Type 173 |
TheBristol Type 192 Belvedere is a British twin-engine,tandem rotor militaryhelicopter built by theBristol Aeroplane Company. It was designed byRaoul Hafner for a variety of transport roles including troop transport, supply dropping andcasualty evacuation. It was operated by theRoyal 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 byPiasecki orBoeing.
The Belvedere was based on theBristol Type 173 10-seat (later 16-seat) civilian helicopter which first flew on 3 January 1952. The 173 project was cancelled in 1956, and Bristol spent time on the Type 191 and Type 193 toRoyal Navy andRoyal Canadian Navy specifications. These two naval variants were cancelled, but the RAF expressed an interest in the aircraft and the Type 192 "Belvedere" was created. Three Type 191 airframes were almost complete when the order was cancelled, but they were used to aid the development of the Type 192. The first two were used as test rigs for the newNapier Gazelle engines and the third was used for fatigue tests.[1][2]
The Type 192 shared some of its design features with the cancelled naval variants, which made it less than ideal for transporting troops. The front undercarriage was unusually tall, originally designed to give adequate clearance for loadingtorpedoes underneath thefuselage in theanti-submarine warfare role. This left the main passenger and cargo door 4 feet (1.2 m) above the ground. The engines were placed at either end of the cabin. (By comparison the contemporary purpose-designed troop transportBoeing Vertol CH-46 Sea Knight had its engines above the aft cabin to permit a rear loading ramp). To provide access to the cabin from thecockpit there was a small entry past the engine that resulted in a bulge on the left side of the fuselage.[1][3]
The first Type 192 prototypeXG447 flew on 5 July 1958 with tandem wooden rotor blades, a completely manual control system and a castored, fixed quadricycleundercarriage. From the fifth prototype, the rotors fitted were all-metal, four-bladed units. Production model controls and instruments allowed night operations. The prototype machines had an upwards-hinged main passenger and cockpit door, which was prone to being slammed shut by thedownwash from the rotors. This was replaced by a sliding door on the later aircraft.[3]
Twenty-six Belvederes were built, entering service as theBelvedere HC Mark 1. They were originally designed for use with the Royal Navy but were later adapted to carry 18 fully equipped troops with a total load capacity of 6,000 lb (2,700 kg). The two rotors were synchronised through a shaft to prevent blade collision, allowing the aircraft to operate through only one engine in the event of an emergency. In that case, the remaining engine would automatically run up to double power to compensate.[4]
Bristol attempted to market a civilian variant of the helicopter, designated theType 192C. The 192C would have had seats for 24 passengers and was aimed at intercity services.[5] To demonstrate the aircraft's potential, Bristol chief test pilot Charles "Sox" Hosegood set the London–Paris and Paris–London speed records in May 1961 in a Belvedere.[6] However, no orders were placed for the 192C.[7]
Three pre-production Belvederes (XG453, 454, 456) went to the Belvedere Trials Unit atRAF Odiham, which was subsequently reformed asNo. 66 Squadron RAF in 1961. Engine starter problems caused trouble at first, but operational deployment continued. The production aircraft saw service in Europe, Africa,Southern Arabia andBorneo. Meanwhile, the original prototypeXG447 was broken up atPorton Down on 7 August 1966.[8]
In June 1960 the fifth prototype,XG452, set a speed record of 130 mph (210 km/h) betweenGatwick andTripoli. In 1962 a 72 Squadron Belvedere lowered the 80 ft tall spire onto the newCoventry Cathedral.[9]
As well as 66 Squadron, the type was deployed to72 Squadron in 1961 and26 Squadron in 1962, all at Odiham. 26 Squadron later transferred toRAF Khormaksar where it disbanded in November 1965. The helicopters were transferred byHMSAlbion to Singapore to join 66 Squadron until that squadron was disbanded in 1969. 72 Squadron kept its Belvederes until August 1964 when it exchanged them forWestland Wessex.[10]
The RAF Belvederes were involved in combat in theAden Emergency and inBorneo (during theIndonesia–Malaysia confrontation).
The following Bristol Belvederes have been preserved and are either on display or undergoing restoration.
Belvedere HC.1
Data from Flight 1962[14]
General characteristics
Performance
Related development
Aircraft of comparable role, configuration, and era
Related lists
