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Aviation History
1955
1955 - 0742.PDF
740 FLIGHT, 27 May 1955 CORRESPONDENCE The Editor of "Flight" does not hold himself responsible for the views expressed by correspondents in these columns;the names and addresses of the writers, not necessarily for publication, must in all cases accompany letters. British Prestige in America ~ x I AM sorry I have not been able to write to you earlier about anarticle which appeared in Flight on April 15th entitled "British Air Prestige in America." The subtitle of this article indicates thatthe writer of the article feels that there is a serious lack of publicity for British aircraft in North America.I do not wish to discuss the question of publicity, but your correspondent—"A.B.T."—goes a great deal further than thisand suggests that, both in informed and uninformed circles in the U.S., British air prestige has lapsed seriously, during the lasttwelve months. He goes even further and suggests that the enquiry into the Comet accidents has contributed to this loss of Britishprestige. He speaks of "an almost slanderous attack in a vast section of the American Press." I read a number of reputable American daily and weekly non-technical papers and I also study American aviation journals. I travel around a good deal in the United States. My understand-ing of American opinion differs very greatly from "A.B.T.'s" In particular, I have never heard anything but the greatest admirationfor British integrity, not to say scientific and engineering ability, expressed in connection with the Comet enquiry. To say that theAmerican Press has made a slanderous attack on British aviation seems to me to be incorrect and unfair. It so happened that I read this article immediately after return-ing from a panel meeting of the Society of Automotive Engineers held to compare British and American practice in the field ofaircraft turbine design and manufacture. At this conference American speakers went out of their way to express admirationfor British methods and British products and they expressed themselves as being more than aware of British pioneering in thefield of turbine-engined civil aircraft. Nothing could have been more generous than their attitude. I think that "A.B.T." has been too extreme in both directions,for I do not remember any time when the Americans "accepted as readily Great Britain's leadership in the air as they had onceher supremacy on the seas." I think that any Britisher over here who has some knowledgeof the facts should endeavour to put this matter in a fair perspec- tive. Washington, D.C. S. SCOTT-HALL. The Channel WingI WAS most interested to see the letter which inquired aboutchannel-wing developments. I have not heard of anyone else working on these lines in this country, but I have taken a greatinterest in them myself; and, back in 1947, I conducted a series of experiments with various forms of channel. I was at that timeespecially interested in the possibilities of jet lift, to which this form lends itself. (Could I dare claim to be first to think of thiscombination?) Going back to first principles, which is always an instructiveexercise, it seemed to me that the principle of sustained flight by the indirect use of engine power was a rather inefficient way ofdoing things, for in most aircraft the lift is not provided by the direct action of the slipstream from the props, but by the reactionof the air and the moving wing. A far more efficient lift is provided by the system recentlydecribed in Flight, in which a region of high pressure is created directly under the wings. This appears to be the only case whereit is of real benefit (structural considerations apart) to have the props on the leading edge, where their presence normally createsfurther problems of form drag. Even more efficient lift is pro- vided by sucking the air along the top of a channel wing, Custerstyle. The gain in efficiency by direct use of the slipstream is remarkable. Even higher efficiencies would be obtained, I con-tend, by a combination of these principles and modified wing shapes. Flying at very low speeds with high lift does bring usto a limiting point where quite modest turbulence in the air will produce correspondingly high changes in attitude, and make fordifficulties in control. I understand the Custer wing was invented around 1943, andwind tunnel tests were performed by the (then) U.S.A.A.F. in 1946, at Wright Field. It is said that this shape has very highvalues of CL, but it is difficult to calculate as the ordinary formula; are derived from considerations of long spans with correctionsfor finite sections, and there is also gain from the compressibility effect in flight, due to wing shape. Doubtless you will be ableto tell us more of the latest tests, but it was calculated that 75 per cent of the lift was generated before the craft moved forward, thisbeing achieved by sucking the air over the top surface. Many interesting alternatives suggest themselves, such as the result of combining this with the blowing principles mentioned earlier,or the application of jet lift using a turboprop, to mention a couple of idle fancies.Of the snags, the first one Custer hit was that no one would fly such a queer thing, which pinpoints the lack of control surfaces.No flaps, ailerons or dihedral to take the strain. Even so, it flew! It does seem that any sudden change in turbulent conditions ofthe angle of attack would lead to equally sudden stall, with that sharp edge. This is aggravated at low speeds by the great increaseof resistance to turbulent as compared with laminar flow in bodies of this shape (see 7th-root law). It is this more thananything which militates against the prospects of vertical take-off, either with this scheme or with jets. For high safety, a completecontrol of the airstream on both upper and lower surfaces is called for at zero speed, and to date only the helicopter approachesthis ideal. I believe that these snags could be overcome, and that the wingshape could be modified to approach even nearer to the theoretic- ally ideal ellipsoid shape (and the devil take the production diffi-culties !). But then I am only a freelance, too, and I don't think the British companies would pay us much attention either; and,even if they did, it would probably not be worth the worry and the bother by the time the Government had taken the lion's shareof the proceeds. Casdetown, Isle of Man. MICHAEL B. HAWTON. Armstrong and the Camel TT was with pleasure that I found, in reading the article on theA Sopwith Camel in your issue of April 22nd, reference to a certain Capt. Armstrong. In the past I have myself writtena number of articles about this pilot, in various journals, and it is gratifying to find that after 37 years he is not forgotten. I first witnessed Armstrong's extraordinary ability to exploitthe astonishing manoeuvrability of die Camel in unusual circum- stances. This was when I was coming in to land at Waddonin an Avro 504 one evening in 1918. Below me I spotted a Camel flying at zero feet (as its shadow indicated) and then, a momentor two later, I saw it going up in a vertical climb immediately in my line of flight. I continued to watch the machine and saw itinverted immediately above me and go down in my rear to complete the lowest, neatest and tightest loop I had ever seen.Some weeks later Armstrong appeared again at Waddon. He flew across the aerodrome so low that his wheels brushed the longgrass and, on reaching the tarmac fronting our Bessoneau hangars, carried out a flick roll which left every spectator speechless. Hiswing-tips cleared the ground by not more than 12 inches. He proceeded to carry out a number of circuits and repeated theperformance with loops and rolls again and again before landing. Our CO. emerged from his office demanding to know in furiousterms who had been indulging in this sensational and hazardous flying; but subsequently he melted and invited Armstrong to themess for lunch. From time to time in the past 30-odd years I have met people(including an ex-pilot of die U.S. Army Air Corps) who have enquired as to whether I had ever seen "a fellow named Arm-strong" fly a Camel. I remember, too, Sir Christopher Quintin Brand saying to me that Armstrong was, in his opinion, the finestand most accomplished Camel pilot he had ever met. London, S.W.I. GRENVILLE MANTON. FORTHCOMING EVENTS May 27. Royal Aircraft Establishment: Senior Staff Mess Ball. May 28-29. Frejus St. Raphael Air Rally, France. May 29-30. Aero Club of Ireland: Flying Display. May 29-30. S.M.A.E.: British National Model Aircraft Championships, R.A.F. Station Waterbeach. May 30. R.Ae.C: Second National Air Races meeting (in conjunction with S.S.A.F.A. air display), Yeadon. May 30. Royal Netherlands Aero Club: International Air Display: Ypenburg. May 30. Women's Junior Air Corps: Air rally. White Waltham. May 30- Canadian International Trade Fair and Air Show, Toronto. June 10 June 1-11. Aluminium 1955 Exhibition: Royal Festival Hall, London. June 1-11. British Plastics Exhibition and Convention: Olympio, London. June 1-18. Royal Tournament, Earls Court, London. June 3-17. Aeronautical Union of Jugoslavia: Sixth Federal Gliding Contests, Jugoslavia. June 4-5. Ninth Rally of the Wines and Chateaux of Anjou, France. June 4-5. Royal Air Forces Association: Annual Conference. June 7-15. French Aero Club: F.A.I. 50th Anniversary Rally, Paris. June 10-19. Paris Aero Show. Sept. 5-11. S.B.A.C. Show, Farnborough.
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