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Aviation History
1943
1943 - 1757.PDF
JULY 5TH, 1943 FLIGHT The Bristol Giant What, in Practice, the Published Power Units andW HILE it is extremely gratifying to find the dailyPress taking such a keen interest in post-war British civil aviation, it is rather regrettable thatpremature, incomplete and to some extent inaccurate in- formation should have been published by certain dailies.There may be good reasons for the Minister of Aircraft Production wishing to say nothing at present about thedetails of the four prototypes of aircraft which, as he annouunced in the House some time ago, have been en-trusted to firms in the aircraft industry. They were selected on the recommendations of the Brabazon Com-mittee, and in the short period that has lapsed since, it is scarcely possible that the plans of the firms can be veryfar advanced. Thus, although broad outlines may have been decided upon, there must necessarily be many detailsand data which are still tentative. Such data as have been published concerning the typeof aircraft on the design of which the Bristol Aeroplane Co., Ltd., is engaged have been largely speculative, and cer-tainly unauthorised. That this is so is evident from the fact that the weight of the machine has been quoted asbeing anywhere between 100 tons and 200 tons. It has been suggested that passenger accommodation will be for150 by day and for 70 or 75 when sleeping accommodation is required. That such a project can scarcely be beyond the tentativestage emerges from an examination of what the figures really mean. Even at the lowest weight quoted, 100 tons,that means 224,000 lb. To get a fairly high cruising speed it is obvious that the wing loading will have to be high,which is merely another way of saying that the power loading must be fairly low to get off with a reasonable run.In any case, it will have to be moderate if cruising is to be done on the customary percentage of full power. A reason-able assumption for power loading would be 10 lb./h.p., based on take-off power. m ^ , Unless Mr. L. G. Frise, Bristol's chief aircraft designer,is contemplating jet propulsion, of which there has been no suggestion published, he must have based his designon power plants which are already in existence, or which may be assumed to have become available by the time theBristol giant can be completed. It seems reasonable to expect that a single-unit take-offpower of 3,000 h.p. may by then be available. At a power loading of 10 lb./h.p. that would need more than sevenunits of 3,000 h.p. each, so that the logical deduction is that eight such units must be contemplated if the gross Figures Would Mean : Multiple Undercarriages weight is ioo tons. At the 130 tons gross weight, which hasalso been mentioned, ten engines of 3,000 h.p. each would be needed. Since it is scarcely likely that Mr. Frise would arrangehis numerous engines in line abreast right across the wing span, it appears obvious that he must be contemplatingsome combination of engines into units. For instance, if eight engines were to be used, they could be grouped infour units of two engines each, a unit driving either a common airscrew or two contra-rotating airscrews. Power plant installation is but one of many problemsconfronting the designer of an aircraft of such size. The undercarriage is one of the more obvious. The concentra-tion of weight on two wheels (or even on three, if a tricycle is used) would be excessive, and a multiplicity of wheelswould have to be adopted. These could be arranged as in the Me 323, an arrangement to which there aremany objections, or they could be placed spanwise in line abreast. The latter arrangement of undercarriage wheels suffersfrom the disadvantage that any unevenness of the airfield would impose fairly severe stresses on the wing structure,but in any case a giant aircraft would need a smooth run- way so that this part of the problem might not be veryserious. A burst tyre would set up local stresses in the wing, but these would probably be of less consequencethan a burst tyre on an aircraft of such size if the ortho- dox type of undercarriage were used. Our readers will appreciate that there is no officialauthorisation of the gross weight figures quoted. In fact, the Bristol company uses about the information publishedthe expression "unauthorised and incorrect." We need hardly add that when official quarters decide that the in-formation may be published. Flight will have it as a matter of course. All we have done is to show what sort of air-craft would result from loaded weights of 100 to 130 tons. They serve, we think, to show that a jump from theheaviest landplane in use to-day to a commercial machine of such weights gives rise to many problems, and thatfeatures at present untried will have to be introduced. That is in no way intended as a criticism. On the contrary, the Bristol giant is part of a long-range policy, and if it is not to be out of date by the time it can be got intoservice it will have to make use of features about which at the moment little is known from experience, but whichmay reasonably be expected to have "been tried out before actual construction has progressed very far. THE GIBRALTAR AIR ACCIDENT SHORTLY after taking off from Gibraltar on the night ofJuly 4th-5th, a Liberator of the R.A.F. Transport Com- mand, containing 11 passengers and a crew of six, crashed intothe sea; the only survivor was the aircraft's Czech pilot. The aircraft was bringing back to England General Sikorski,the Polish Prime Minister and Commander-in-Chief, who had been on a visit to the Middle East, and with him was his28-year-old daughter, Mde. Zofja Lesniowska, who was Chief of the Polish Women's Services; Colonel Victor Cazalet, M.P.,liaison officer to General Sikorski; Maj. Gen. Klimecki, Chief of the Polish General Staff; Col. Marecki, who was attachedto the Polish General Staff in London; L't. Ponikiewski, of the Polish Navy, who was A.D.C. to General Sikorski; M.Kuakowski, his private secretary; and Col. Gralewski. Up to the time of going to press no precise informationabout the accident has been officially released for publication, other than that it happened soon after the Liberator had takenoff during the hours of darkness and that the machine plunged into the sea, with the loss of all on board except the pilot. The news reached London in a telegram to the ColonialOffice from the Governor of Gibraltar, and the Polish ministers in London were at once informed, with the result that aCabinet meeting was at once called at the Polish Government offices in Kensington Palace Gardens. General Sikorski made his trip to the Middle East to inspectPolish troops in Syria, Egypt, Irak and Persia, and it was reported at the time that he made the trip against the adviceof high Polish officers, who feared that some accident might befall him. It was his second visit to the Middle East duringthe war, for he was at Tobruk during the seige, and he had also flown to America twice and to Russia to confer with Stalin. His daughter'accompanied him in her capacity of Chief ofthe Polish Women's Services, with the special object of inspect- ing large numbers of Polish women who had recently arrivedthere from Russia. Her husband is a prisoner of war in Germany. General Sikorski's visit to the Middle East was saidto have been in connection with the United Nations offensive. Gas Turbines and Jet Propulsion for Aircraft By G. GEOFFREY SMITH, M.B.E. A second edition of the above booklet is now available from " Flight " publishing offices. The new work consists of ten chapters and includes many llustrations. Price 3/6 plus 3d. post.
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