'From 1943, George Miles helped his brother with the M.52, an experimental jet aircraft which promised to lead the world in supersonic flight. But in 1946 the government-funded project was abruptly cancelled by Sir Stafford Cripps, Minister of Aircraft Production. Cripps compounded the blow by ordering the Mileses to hand over their designs to the American Bell Aircraft Company. On October 14 1947, Major Chuck Yeager, of the United States air force, made the world's first supersonic flight in a Bell-X1.'That is not the first account of the Atlee government ordering the transfer of advanced aviation research and technology to the Americans I've read or heard. In my boyhood and youth I was told similar tales of decisions that, if true, can in no way be considered to have been in our best long-term national interests. The excerpt was taken from here. I hope no one there objects.
'The Miles M.52 was a turbojet powered supersonic research aircraft project designed in the United Kingdom in the mid 1940s. Design work was undertaken in secrecy between 1942 and 1945. In 1946 the Air Ministry controversially changed the project to a series of unmanned rocket-powered scale aircraft, launched from a modified de Havilland Mosquito. In a successful test flight Mach 1.38 was achieved by a scale model in normally controllable transonic and supersonic level flight, a unique achievement at that time which validated the aerodynamics of the M.52. At that point the ministry cancelled that project and issued a new requirement which was to result in the English Electric Lightning. Work on the afterburning version of the Power Jets W.B.2/700 turbojet was also cancelled and the Power Jets company was incorporated into the National Gas Turbine Establishment.'this:
' ... Miles had ... submitted several proposals for advanced aircraft in response to ministry specifications. In order to resolve a dispute about a contract mishandled by the Ministry of Aircraft Production, the company was invited to undertake a top-secret project to Air Ministry Specification E.24/43 for a jet-powered research plane to reach supersonic speeds. The contract, awarded in October 1943, called for an "aeroplane capable of flying over 1,000 mph (1,600 km/h) in level flight, over twice the existing speed record, and climb to 36,000 feet (11,000 m) in 1.5 minutes." The specification was intended only to match the supposed performance of a German aircraft: the 1,000 mph (supersonic) requirement resulted from the mistranslation of an intercepted communication stating that the maximum speed was 1,000 km/h (subsonic). This report dealt with the Me 163A and/or the Me 262.
Many early jet aircraft had round noses, thick wings and hinged elevators, giving them critical Mach numbers well below the speed of sound, and were less suitable for research into high subsonic speeds (in dives) than the Spitfire with its thinner wings. RAE tests with the Spitfire in 1943 had proved that drag was the main factor to be addressed in high speed aircraft.
A huge number of advanced features were incorporated into the resulting M.52 design, many of which hint at a detailed knowledge of supersonic aerodynamics. With no other sources of such information Miles had turned to design data for stabilising projectiles. In particular, the design featured a conical nose and sharp wing leading edges, as it was known that round-nosed projectiles could not be stabilised at supersonic speeds. The design used very thin wings of biconvex section proposed by Jakob Ackeret for low drag. These wings were so thin that they were known to test pilots as 'Gillette' wings, named after the famous razor. The wing tips were "clipped" to keep them clear of the conical shock wave generated by the nose of the aircraft. The fuselage had the minimum cross-section allowable around the centrifugal engine with fuel tanks in a saddle over the top.
Another critical addition was the use of a power operated stabilator, also known as the all-moving tail or flying tail, a key to supersonic flight control which contrasted with traditional hinged tailplanes (horizontal stabilizers) connected mechanically to the pilots control column. Conventional control surfaces became ineffective at the high subsonic speeds then being achieved by fighters in dives, due to the aerodynamic forces caused by the formation of shockwaves at the hinge and the rearward movement of the centre of pressure, which together could override the control forces that could be applied mechanically by the pilot, hindering recovery from the dive.
An initial version of the aircraft was to be test flown using Frank Whittle's latest engine, the Power Jets W.2/700, calculated to give transonic performance, except in a shallow dive where it would go supersonic. Meanwhile it was planned to develop a fully supersonic version of the aircraft by incorporating a reheat jetpipe - also known as an afterburner. Extra fuel was to be burned in the tailpipe to avoid overheating the turbine blades, making use of unused oxygen in the exhaust. To supply more air to the afterburner than could move through the fairly small engine, an augmentor fan powered by the engine was to be fitted behind the engine to draw air around the engine in ducts.
Finally the design included another critical element, the use of a shock cone in the nose to slow the incoming air to the subsonic speeds needed by the engine ... 'this:
'In 1944, design work was considered 90% complete and Miles was told to go ahead with the construction of three prototype M.52s. Later that year, the Air Ministry signed an agreement with the United States to exchange high-speed research and data. Miles Chief Aerodynamicist Dennis Bancroft stated that the Bell Aircraft company was given access to the drawings and research on the M.52, but the U.S. reneged on the agreement and no data was forthcoming in return. Unknown to Miles, Bell had already started construction of a rocket-powered supersonic design of their own, but with a conventional tail were battling the problem of control. A variable-incidence tail appeared to be the most promising solution; the Miles and RAE tests supported this. Later, following conversion of the tail, pilot Chuck Yeager verified it experimentally, and all subsequent supersonic aircraft would either have an all-moving tailplane or a delta wing.'this:
'By February 1946, the new Labour government introduced dramatic budget cuts. The Director of Scientific Research, Sir Ben Lockspeiser subsequently cancelled the project. Other factors contributing to the cancellation included doubts about pilot safety, as well as some German research that seemed to point to swept wings being desirable at supersonic speeds.
At cancellation, the first of the three M.52s was 82% completed, with test flights planned to begin in a few months. The test programme involved the progressive testing and development of the M.52 by the RAE, initially without reheat installed, with the aim of achieving Mach 1.07 by the end of 1946.
Miles Aircraft Ltd entered receivership in 1947 and the company was subsequently re-structured; its aircraft assets including the design data for the M.52 were acquired by Handley Page. Cancellation of the project considerably set back British progress in supersonic design technology.'and this:
'Several thousand pounds would have been required to complete the first M.52. Instead, the government instituted a new programme involving expendable, pilotless, rocket-propelled missiles. The design was passed to Barnes Wallis at Vickers-Armstrongs, and the engine development took place at the RAE. The result was a 30% scale radio-controlled model of the original M.52 design, powered by an Armstrong Siddeley Beta rocket engine.
The first launch took place on 8 October 1947 at high altitude from a DH Mosquito, but the rocket exploded shortly after release. Only days later, the Bell X-1 broke the sound barrier. There was a flurry of denunciation of Labour's decision to cancel the project, with the Daily Express taking up the cause for the restoration of the M.52 programme, to no effect. On 10 October 1948, a second rocket was launched, and the speed of Mach 1.38 was obtained in stable level flight, a unique achievement at that time. Instead of diving into the sea as planned, the model failed to respond to radio commands and was last observed (on radar) heading out into the Atlantic. Following that successful supersonic test flight, further work on this project was cancelled,[14] being followed up immediately by the issue of Ministry of Supply Experimental Requirement ER.103 (below).
Many important design principles incorporated in the M.52 did not reappear until the mid- to late 1950s, with the development of truly supersonic aircraft such as the Fairey Delta 2, and the English Electric P.1 which became the highly regarded English Electric Lightning. Both of those aircraft were developed in response (initially) to requirement ER.103 of 1947, informed by the knowledge gained from the M.52 aircraft and missile research projects together with German experimental data.'The story makes sad but all too familiar reading.
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