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Aviation History
1950
1950 - 2061.PDF
FLIGHT, 30 November 1950 50? 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. 9 H.P.42 History "DEGARDING recent information published in Flight aboutJ»v the H.P.42, I am able to supplement one of the facts men- tioned. Horsa G-AAUC and Hadrian G-AAUE were both seenin their war paint at Doncaster Airport during 1942. One of these machines, picketed in the open, was blown adrift andcompletely wrecked by a gale in that year. In view of Captain Brown's letter in Flight of October 5th, I conclude the wreckedmachine would have been Hadrian. Doncaster. L. A. CLARK. Airline Comfort WITH reference to Mr. I. Scott-Buccleuch's letter on " AirlineComfort" in your issue of November 16th, the aim of all scheduled airline operators is to fit their aircraft to the routesin the most profitable manner compatible with the operational performance of the type on the one hand and the length andphysical nature of the journeys from the passenger's angle on the other. B.O.A.C. is no exception in this and, as your correspondentwould seem to suggest, the examples of our passenger seating quoted by him are primarily due to the range and payloadcharacteristics of the particular types. The increase in seating capacity of the Solents was a typicalcase where, after initial operating experience, a higher take-off weight along the routes became possible, and performancegenerally was progressively improved. This commonly occurs during the initial operation of a new type as the result of upwardrevisions of engine power, and so on. For example, the Hermes IV has now had its all-up weight increased from 82,000to 86,0001b, and this is in process of implementation. Sometimes, as the result of having to operate a particulartype of aircraft on route sectors above the optimum distance for best payload, greater passenger comfort (or "luxury") canbe offered, because payload then becomes weight-limited, and greater space per passenger is automatically available. Examplesof this are frequently seen where operators are using sleeperette- type seats which otherwise could not be provided. The carriageof considerable quantities of mail or freight on passenger services, as is common on B.O.A.C.'s overseas routes, is anotherfactor contributing to what otherwise might appear to be an extravagant spacing of passenger seats. It was naturally our aim to establish an interior layout whichgives the most profitable volumetric payload in relation "o the average sector fuel weights estimated to give an acceptabledegree of operational regularity. London, W.I. F. C. GILLMAN,British Overseas Airways Corporation. Sidewash and Stability WITH reference to Mr. WrefordrBush's letter in Right ofAugust 24th, criticizing my article of the above title pub- lished in Flight of July 27th, I should like to apologize for thedelay in making this reply, but I received the appropriate copy of Flight only a few days ago. Whilst agreeing with my critic that the figures quoted in myarticle for the Hawker P. 1040 and P. 1052 are, perhaps, incorrect (they were obtained from miniature three-view G.A. drawings)I do not think that the real figures are as high as Mr. Wreford- Bush quotes. I should not be at all surprised if the aircraft inquestion did not show some oscillatory tendencies. Perhaps Mr. Wreford-Bush did not quite see what I meant by the finarea above the fuselage (SFR) in my approximate formula relat- ing the fin size required to the fuselage size. This formula forms a departure from the well-establishedmethod of estimating n 7 according to R.A.E. and R.Ae.S. datasheets, where the fin area is represented as " the gross area " including a part formed by the fin and fuselage beneath themilplane. However, the fin p/q tests that I have seen in flight and in wind tunnels have convinced me that the theoreticalindicated inefficiency of that part of the fin under the tailplane is a fact. The reason for it can easily be explained when oneconsiders -the fuselage top sidewash annihilated locally by the tailplane frontal downwash due to its own lifting line, this beingespecially apparent when the tailplane is mounted above a circular fuselage. One should try to separate the fin from thetailplane, and if the tailplane must be mounted away from the id wake'of the wing, then it should be put either right on top of the fin or right below it, even if it means usinganhedral. For further studies of the subject, I would recom- mend Aerodynamics of the Fuselage, by H. Multhopp. This isavailable as an M.O.S. translation (R.T.P. No. 1220). I agree with Mr. Wreford-Bush that my formula is approxi-mate, but then, so is the R.Ae.S. method. By the latter, one can make practically every modern aircraft look stable or un-stable on paper—depending, for example, on how much one allows for, say, canopy height. Furthermore, the R.Ae.S.method of estimating n v does not lend itself easily to projectwork, where one has to relate stability with performance and weight in a hundred and one variants. The old rule of tailvolume also fails when one starts changing the wing loading and aspect ratio. Such is the " exact" science of aerodynamics.Nevertheless, one has to find some method of quick comparison for project work, and my formula gave me the best approxima-tion so far available. I think it worth mentioning that most aircraft which show low values in the tables published in myoriginal article have had stability troubles. I should be pleased to hear if Mr. Wrefqrd-Bush has anything better to offer as arough recipe for project work. Further to other points raised by my critic, I agree that theparagraph concerning stability effects of the fuselage nose shape does not specifically state that the fuselage discussed is in thepresence of the wing: that much I took to be assumed. I must, however, disagree with Mr. Wreford-Bush when he claims thatmy formula does not take the fuselage nose shape into account. It is, in fact, the very thing that the formula does take intoaccount, containing, in effect, the term of fuselage volume and mean width in front of the e.g. H. K. MILLICER. Melbourne, Australia. An Expert on Veterans I HAVE been most interested in the correspondence concern-ing veteran aircraft which has appeared in recent issues of Flight, and I believe I might be abie to assist in clearing upsome of the points raised. Firstly. One of your very rare caption mistakes occurred inyour R.A.F. Display report, when the photo of the Shuttle- worth 1909 Bleriot XI was depicted as the Gordon BennettBleriot. This slip undoubtedly occurred owing to the fact that my 1911 Gordon Bennett Cup Bleriot XXVII was displayed inthe static park. I believe the points raised in other letters bad better be gener-ally covered by referring to the Bleriot types, as correspondents appear to have mixed up the Bleriot XI and XII in connectionwith Gordon Bennett events. Mr. Curtis also mentions that the Shuttleworth Bleriot had a "Cross-Channel type" rudderbefore the war. This latter point - can be cleared up by my mentioning that my No. 5 Bleriot XI, which comprised No. 5fuselage and engine and the remainder rebuilt from original Bleriot works drawings, was fitted with the Cross-Channel typerudder for film purposes and was also fitted with the Cross- Chihnel wings, which gave a span about 18in less than the pro-duction type XI. The Shuttleworth Bleriot attained at least 200ft altitude and my No. 5 short-span flyer about 100ft, beforethe war (1939-45); my No. 5 was probably very slighdy faster. These altitudes were often accomplished in the period 1909-10and, in fact, M. Molon on my Type XI No. 54 accomplished 600ft towards the end of 1909. The actual Cross-Channel Bleriot XI had a rudder with asingle balanced portion above the fuselage and this general appearance (not necessarily exact design) also applied to the1911 type Xlbis and the 1912 type XXI. The Bleriot types IV, IX, XI and XIa all had rudders of practically identicalappearance, there being a balanced portion above and below the fuselage, similar to two horns. There is mention of a Bleriot which was flown ai Rheimsother than the types XI and which housed the pilot inside the fuselage. This was the Type XII Bleriot high-wing mono-plane and was brought out in 1910. It had type XI wings and various motors were fitted, including an eight-cylinderE.N.V., Green, and Darracq of about 35 h.p., water-cooled. I believe a Gnome was also fitted. Bleriot first flew this type atPau and it was also flown by Grahame-White. Speeds of 45 to 60 m.p.h. were attained. The Gordon Bennett Bleriots were of types XI and XIadesign, fitted with Gnome 50 and 100 h.p. motors for 1910-11 and Type XXVII fitted with ?0. 70 and 100 h.p Gnomes for
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