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Aviation History
1921
1921 - 0278.PDF
APRIL 1921 •/^^/••m^:y CORRESPONDENCE AV - ~ The Editor does not hold himself responsible for opinions expressed by correspondents. The names and addresses of the writers; not necessarily for publication, must in all cases accompany letters intended for insertion in these columns. THE GLENN MARTIN' HIGH-LIFT WING [2041] In connection with your note in FLIGHT on the Glenn Martin No. 2 Wing, I should like to make two or three comments. The highest lift coefficient yet published for the Handley Page wing, as far as I am aware, makes Q = 0.8 (absolute units), or L, = 0.00408 (lbs. per sq. ftv.-m.p.h. units). The comment was made that with several slots the coefficient can be raised to close upon C] — 2.0, but no indication was given that any such lift had actually been attained. The article containing these statements appeared in FLIGHT for October 28, 1920. It is possible that you have information not yet made public, or that we have overlooked some other data on the Handley Page Wing. We should be glad to obtain any information you can give us on this subject. In regard to the efficiency of Glenn Martin No. 2 at liigh speeds, you have apparently mistaken the statement in our letter. It does not refer to the maximum L/D, which, although high for a wing of this thickness, does not compare with that of the best thin wings. However, at an incidence corresponding to twice the minimum speed the L/D of Glenn Martin No. 2 with flaps is 15.1, and for three times the minimum speed, 8.4. The corresponding figures for the R.A.F. 15 are 14.5 and 7.7. Furthermore, these figures contain no allowance for reduction of parasite resistance by use of internal bracing in the case of Glenn Martin No. 2. For further information reference should be had to the Journal of the Society of Automotive Engineers, for March and April of this year. Prior to the publication of the report in the Journal, we did not feel at liberty to issue detailed descriptions or data. We agree with you that this wing is nothing to get wildly excited about. It has specific uses. Where high speed or reduction of wing area must be attained we believe it to be the best wing now available. The variation of camber in flight is excellent in theory, but difficult to operate in practice. It is rumoured that the Handley Page Company has not yet succeeded in perfecting a satisfactory operating mechanism for the Handley Page wing. The Glenn Martin No. 2 involves no detailed construction differing from current practice, since flaps and ailerons are alike. We, therefore, feel that at the present time it is one of the half-dozen most valuable wings at the disposal of the aeronautical engineer. C. D. HANSCOM, Chief Engineer. [Since Mr. Hanscom wrote this letter, the figures relating to the Handley Page wings have been published, and show that the claim advanced in the letter to which we referred, i.e., that the Martin No. 2 wing is " the highest-lift wing in the world," does not hold. The data supplied with the drawing of the wing section, published in our issue of February 17, 1921, were of such meagre nature as to fail to substantiate the claims made. Since then the figures relating to the Martin No. 2 have been published, and show a maximum L, of .0040 (0.784 abs.) and a maximum L/D of 14. The Lf of 1.02 and the maximum L/D of 15.1 appear to refer to the section fitted with flaps. As no mention was made of this fact in the original letter, we had no means of knowing that the section was not to be judged as an ordinary fixed section. Undoubtedly, as fitted with flap gear the Glenn Martin No. 2 is a very good wing, considerably above the average.—ED.] THE NAPIER "LION " AND LONDON-PARIS AIR SERVICE [2042] In reference to an advertisement of an engine firm in this week's issue of FLIGHT, in which they state that all the aeroplanes used on the London-to-Paris Air Service are fitted with their type of engine, we would say that this statement is apparently made on the strength of an article appearing in The Times of March 19th, 1921, which states that the Vickers-Vimy, D.H.9, D.H.igs, and Handley Page aeroplanes are being used on the Service. As is well known, there is no such machine as D.H.19, and this is obviously an error for D.H.18, which is fitted with a single 450-h.p. Napier aero engine. You will realise that such a statement in this firm's advertisement is very damaging to us, bearing in mind the fact that the Airco 18 machines fitted with Napier engines are the most satisfactory and economical employed on the Service. The 450-h.p. Napier aero engine is the only single engine which could lift a D.H. 18 machine, which carries eight pas- sengers in addition to luggage and pilot. It might also be recalled that this engine further proved its reliability, economy, and speed in open competition, as the machines which secured the highest prize in each class of the Air Ministry Competitions were fitted with Napier engines. We should be obliged if you would kindly correct the misleading statement which has appeared. F. H. JONES, Publicity Manager, D. Napier and Sons Ltd. 14, New Burlington Street, W. 1, April 15. ROYAL AERONAUTICAL SOCIETY NOTICES Honorary Members.—In response to a request from the Air Ministry, temporary Honorary Membership of the Society has been offered to the following officers repre- senting Foreign Governments while on service in this country :— Cmdr, Evers (Denmark), Cmdr. Sable (France), Chevalier W. Coppens (Belgium), Maj. Graziani (Italy), Maj.-Genl. Itamy (Japan), Capt. Kobayashi (Japan), Capt. de Vaisseau (Netherlands). Capt. Scott Hansen (Norway), Lieut.-Col. Rich (Spain), Iieut.-Col. Mossberg (Sweden), Capt. G. Hain (Sweden), Cmdr. Tiselius (Sweden), Maj. Melvin Hall (U.S.A.), Lieut. R. G. Pennoyer (U.S.A.). Donations.—The Council desire gratefully to acknowledge the receipt of a copy of " The History of the 24th Squadron R.A.F." by Capt. A. E. Illingworth and Maj. V. A. H. Robeson, from Maj. Robeson. Library.—The following book has been received and placed in the Library: " Meteorology," by A. E. M. Geddes, O.B.E., M.A., D.Sc. W. LOCKWOOD MARSH, Secretary AIR MINISTRY NOTICES Summer Time, 1921 : Holland ADDENDUM to Notice to Airmen No. 31 of April 1st, 1921:— 1. Holland,—Summer time (i.e., an advance of one hour on G.M.T.) came into operation in Holland on the night of April 3/4, 1921. Normal time will be resumed on the night of September 25/26, 1921. (No. 34 of 1921.) Aerodromes for Civil Use : Amendments NOTICE to Airmen No. 33 of 1921 (Aerodromes for Civil Use : Consolidated List) is amended as follows :— LIST B. Aerodromes available for civil machines in emergency only, (a) Permanent Service Stations. The following should be added :—Old Sarum (Salisbury). The following should be deleted :—Houton Bay (S), Howden (Airship), Stonehenge'. LIST B. (b) Stations tempirarily retained for Service purposes. The following should be added :—Houton Bay (S) (Thurso), Howden (Airship), Stoaehenge (Amesbury). (No. 35 of 1921.) : V I. Subsidy for Swedish Civil Aviation ' : ^ vice, a grant of 60,200 kroner for 1921 and 60,800 kroner THE Swedish Government has applied for a grant of for 1922 is requested. These sums are less than were recom- 170,000 kroner for 19,21, and 360,000 kroner for 1922. In mended by the Swedish Aeronautical Commission, and given addition, in order to improve the State Meteorological Ser- in a recent issue of FLIGHT. . -
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