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Aviation History
1962
1962 - 0216.PDF
218 FLIGHT International, 8 February 1962 Dr Hooker Speaks —ABOUT THE 88T OLYMPUS AND VTOL PROPULSION LAST week Dr Stanley Hooker, technical director of Bristol Siddeley Engines Ltd, revealed significant details of his company's plans for engines for supersonic and VTOL aircraft. The Anglo-French (BAC and Sud) effort on a supersonic transport was, he said, likely to result in two versions of an aircraft with common engines, wings and systems. The French version would be designed for medium ranges and the British would trade payload for fuel to cross the Atlantic. Both would, in principle, have four engines of the "supersonic Olympus" type in an installation devel oped jointly by Bristol Siddeley and SNECMA—"in principle," because no British Government decision had yet been taken. Externally, the aircraft would closely resemble the Super Caravelle gothic delta exhibited by Sud at the Paris Salon last year. On the score of engine-plus-fuel weight the civil Olympus is claimed to be "the ideal engine" for M2.2 airliners. With variable nozzle and no silencer its noise at 4.2 miles on an optimum flight plan is said to be 99 PNdb, which is acceptable to the civil authori ties. Take-off rating is 28,8001b, and simplified reheat—doubtless derived from the "weheat" system developed for the Orpheus— would allow the acceleration through Ml to take place not at 37,000ft but at 48,000ft in order to attenuate the sonic boom. Acceleration at the lower altitude would create a llb/sq in shock at ground level. If Britain decided not to support SST development, the French would probably exploit the existing SNECMA/Pratt and Whitney agreement to procure an American engine, although no specific P & W civil design yet existed. An eventual order would involve 400 to 500 engines—"a tremendous prize." The British choice of engine was not yet settled, but, according to Dr Hooker, the super sonic Olympus—unofficially said to be the Mk 593—with its estab lished background and the parallel development for the TSR.2, was a "prime favourite." The first flight engine of this family was shown in the final stages of installation in the company's Vulcan XA894. It is fitted in the bomb bay (drawing, page 196) with bifurcated intakes apparently geometrically similar to the actual TSR.2 con figuration. The body of the engine is enclosed in a sealed sleeve within which boundary-layer air provides cooling and fire protec tion, much in the same way as in the defunct Avro Arrow. On the test bench, M2 conditions at high altitude, where intake pressures are equivalent to sea-level static, have been simulated by heating intake air in a reverse-flow chamber fitted with a ring of Proteus flame tubes. The Olympus has proved to be the most reliable engine in RAF service, and the easiest to handle in the air. Bristol Siddeley have discovered a way of preventing exhaust smoke, and existing engines are being appropriately modified. Concerning vectored-thrust VTOL engines, about which some thing was published on page 156 last week, Dr Hooker pointed out that the ideal thrust was 20 per cent greater than the weight of the aircraft, allowing a useful thrust margin for manoeuvring at the hover. The better-than-unity thrust/weight ratio also gave an ideal thrust margin for acceleration to speeds up to M2. Beyond this speed plenum-chamber burning could provide 300 per cent increase in thrust. Equivalent increase at take-off was 30 per cent. Bristol Siddeley were developing pure lift engines for installation where these might be economical and beneficial, with special emphasis on VTOL transports. The first official announcement of one of these lift engines followed; it was the BS.59, a high-ratio turbofan. TheMoA is supporting a component-research programme, and the first BS.59 is scheduled to run as a company venture in August. An impressive film of the P.l 127 at Dunsfold showed the aircraft making spectacular short take-offs from the taxyway, using the great punch of forward thrust for a few yards followed by rapid application of 60° deflection to lift the machine into an immediate very steep climb. Dr Hooker reported that autostabilization was now rarely used and that an RAF test pilot had, in 20min flying without stabilization, learnt to do everything that could be done with the machine. The flight envelope has now been extended to beyond Ml, 40,000ft and to high i.a.s. The P.l 127 had double the range of the Hunter without external tanks and twice the rate of climb. The development programme had "gone like wildfire" since last September, andlthe Pegasus 3 was already producing almost 20,0001b thrust. The Pegasus 4 would give considerably more, allowing the full design gross weight of the P.l 127 to be exploited. The aircraft could operate wherever the fuel could be supplied. A maximum take-off run of 500ft had been stipulated for military applications, and this the P. 1127 could achieve with 2,0001b load, keeping its performance in i.s.a. +25°C by means of water injec tion. At lower loads, with 2001b of cameras for example, VTO could be achieved. The P.1127 was originally envisaged as a replacement for the Fiat G.91, but NATO now required M2 capability for the NBMR-3 and a later design was submitted. Meanwhile, Bristol Siddeley saw the possibility of lift/thrust engines of up to 40,0001b thrust, suitable for modern strike aircraft, most of which were of approximately this gross weight. Dr Hooker obviously was thinking of the BS.100, but did not say so. A NEW "FLIGHT HANDBOOK 11 RECENT catalogues issued by our associate company Iliffe Books Ltd have contained the entry: "Flight Handbook, 6th Edition, in preparation." Today the new edition is published; details are given in the footnote below. The work has been prepared under the general editorship of Flight International's Technical Editor, who writes:— "In view of the fact that the 5th Edition of this well-known work ap peared in 1954 few will quarrel with the contention that a new edition was called for. Even as it was, practically nothing of the earlier volume could be retained, and a heavy load fell on those who did the writing—and here I would like to name James Hay Stevens, Alastair Pugh and my colleague Mark Lambert. Compared with its predecessor, the 6th Edition is sub stantially larger, and it is produced to an even higher standard, with clearer letterpress printing and all half-tone illustrations on art- paper plates. "In answer to the obvious question 'Who is it for?' I would say that no reader of this journal could fail to find it of great interest— and, I hope, permanent value. It is not a handbook of the kind which instructs the reader how to do something, like cleaning a sparking plug. Rather is it a survey of the whole field of modern powered flight. Many of the readers of Flight International must at times have wished for such a reference, for in our weekly journal we have to assume considerable prior knowledge on the part of the reader. This gave rise to little difficulty during World War II, but today there are many people interested in aircraft, and even employed in an aeronautical field, who would be hard put to say just why the B-70 will have hinged-down wing-tips, or even how a turbofan differs from a turbojet. All this sort of thing will be found in the new volume; and found readily, for it has a comprehensive index." Flight Handbook, 4th Edition Page size 8Jin x 5|in; 331 pages, including 60 pages of art plates, eight foldout cutaway drawings and 123 diagrams in the text; price 35s, from any bookseller (or 36s 4d by pest from Iliffe Books Ltd, Dorset House, Stamford St, London SEI).
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