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Aviation History
1964
1964 - 1535.PDF
846 FLIGHT International, 21 May (944 Beagle WA.II6 VTOL AIRCRAFT 1964... power for rotor spin-up. A light streamlined nose can be fitted. Seven WA.l 16s have been built for initial trials, one of which has been bought by the British Army, and they are operating on Permits-to-Fly. A programme has been started to develop the engine to ARB Civil Airworthiness Standards so that a full C of A can be obtained. Beagle Aircraft is doing market research and stimulating interest in the civil WA.l 16: one was exhibited in Bulawayo earlier this year and another will be shown at the British Exhibition in Sydney later this year. Rotor dia, 20ft 2in; length, I Oft 3in; height, bfl I in; • empty weight, 2581b; max weight, SSOIb; max speed, 6Skt; 'normal cruise, SOkt; min level speed, I2kt; min descending forward speed, zero; climb, 1,0O0ftjmin; endurance, over 2hr; max operating wind speed, 43kt. Hawker Siddeley Aviation Ltd 18 St James's Square, London S Wl HS.681 The Coventry factory of the Avro Whitworth Division of HSA has been given a full development contract for this V/STOL military transport to replace the Beverleys and Hastings of the RAF. The project (which was originally called the Whitworth Gloster AW.681 and met a RAF operational requirement) was the subject of political contention and delay (partly over alternative Bristol Siddeley or Rolls-Royce engines) for some two years until, in the Defence White Paper this spring, it was announced that the HS.681 will be built with four Rolls-Royce Medways of some 17,5001b thrust. These engines will be fitted with thrust deflectors (developed from the R-R reversers) and the moderately swept high-aspect-ratio high wing will be fitted with the latest high-lift devices—presumably powerful flaps plus boundary-layer control. In this form the HS.681 is a short-take-off tactical transport. With the addition of lift-jet pods on the wing the aircraft will be able to achieve VTOL with an appreciable payload. The specification to which the HS.681 is being designed is very exacting, and the aircraft is said to have a payload of about 40,0001b, with a range of some 1,500 n.m. at 500kt. A capacious fuselage, with rear load- ing under the high tail, will take most cur- rent and projected military vehicles and there will be the usual provision for air drops, paratrooping and casualty evacuation. P.1127 The origin of this, the original vectored-thrust VTOL aeroplane, goes back to an idea propounded by Michel Wibault for the use of the Bristol Orion to drive lift fans. By 1956 this idea had gained US MWDP support and was in the capable hands of Dr Stanley Hooker of Bristol Aero Engines; he produced a special powerplant proposal by May 1958, which got a MWDP contract (for 75 per cent of the cost) by March 1959—and the first Bristol Siddeley Pegasus was on the bench in September. In 1957 Sir Sydney Camm of Hawker Siddeley discussed the engine with Dr Hooker and, as a company-financed PV, the design of the P.1127 went ahead in parallel with engine development; prototype con- struction started early in 1959 and the first Hawker Siddeley HS.681 (artist's impression) hover took place on October 21,1960, with transition in September 1961. In January 1963 Hawker Siddeley announced that a technical collaboration agreement had been reached with the Northrop Corporation for VTOL aircraft development. Six prototypes of the P.1127 have been built for the MoA by the Hawker Blackburn Division of HSA. These have been used for extensive development flying at the RAE, in the RAF and at the company's airfield at Dunsfold. Trials included deck landings on, and take-offs from, HMS Ark Royal. Nine further aircraft are being built with joint British, American and German funds and a three-nation squadron will be formed at West Raynham this year. With this squad- ron the operation and logistics of VTOL tactical flying will be intensively evaluated. Designed from the start not as an experimental prototype but as a fully operational strike/reconnaissance fighter to replace the Fiat G.91 or the Hunter, tbe prototype P.1127 had a 13,5OOlb-thrust engine, while the development aircraft have a later Pegasus delivering greater thrust. Performance is similar to that of the Hun- ter, Mach 1 can be exceeded in a shallow dive, and recently it was stated that the ferry range, using conventional take-off, is 2,000 n.m. Much is made by the vectored-thtust proponents of the advantages of STOL take-off when the aircraft weight exceeds the thrust, the ability to do engine power checks with nozzles horizontal, and the use of short ground rolls at take-off and landing, where debris might be blown up and ingested by the engine. In the P.1127 the conventional stick and rudder bar operate the wing-tip, nose and tail jet valves (shutters) when the ailerons, elevator and rudder are deflected. The con- trol jets are supplied by compressor bleed air and they are directed downward, although the tail jet also swivels to give a yawing moment when the rudder is deflected. A lever alongside the throttle gives deflection of the by-pass fan and turbine efflux nozzles. As the nozzles are rotated downward they provide an upward thrust component evenly balanced about the e.g., and this has the effect of reducing the wing loading. Fully deflected, all the lift is provided by the thrust and the aircraft can then move around like a helicopter, e.g., it can travel forward by tilting the nose down to get a propulsive component. For deceleration into jet- supported flight the nozzles are turned slightly beyond the vertical and the nose is lifted. The P. 1127 is normally flown without autostabilization throughout the range from hovering to wing-supported flight and back again. For the tripartite squadron the P.I 127 has been slightly modified: the tailplane has marked anhedral, the wing trailing edge is swept back, the nose has been extended, the fuselage over the wing is slightly humped and the engine air intakes have been altered to tidy the boundary-layer bleed and improve cockpit entry. The inflatable intake-lips, which ensure a good air mass flow at zero and low speeds, have been retained. Large underwing containers of fuel or military stores can be mounted on a pylon under each wing. Span, 23ft Am; length, 42ft; height. I Oft 9in; ml sP"" lift Win.
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