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Aviation History
1929
1929 - 0280.PDF
FEBRUARY 7, 1929 "EXPERIMENTAL FLYING." A Lecture by Flight-Lieut. L. Ragg to the Westland Aircraft Society ONE OJ the most fascinating subjects from the point of view of both thelayman and the aeronautical student i<* " Experimental Flying," and the members of the Westland Aircraft Society, the Veovil Branch ol the RoyalAeronautical Society, were doubly fortunate on January 23 on hearing a lecture on the subject delivered by no less a person than Flight-Lieut. LintonRags, A.F.C., R.A.F., A.K.Ae.S. (R.A.F., Farnborough), aptly described by Capt. G. T. R. Hill, of the Westland Aircraft Works, who presided, as" the most brilliant of that brilliant ban-i of pilots which forms the test staff at Farnborough." In the course of an exceedingly interesting and incidentally entertaininglecture Flight-Lieut. Ragg broached the question of the theory of the spinning nose dive regarding which comparatively little was known untilquite recently, and owing to the complexity of its nature a successful imita- tion of it in the scale model tests in the Wind Tunnel had defeated all attemptsto solve its mysteries. For some years past a special machine had been engaged solely on experiments on spinning and, although that particulartype of aircraft was known to be reasonably safe in the spin, the job was not a popular one amongst the experimental pilots. To fly for an hour orso, and solemnly spend the whole time alternatively climbing up to 8,000 ft. or 10,000 ft., and spinning down again, lost its fascination after a while, andwas liable to dampen the ardour of even the most enthusiastic and un- imaginative. During the whole of the spin there were violent accelerations in threedimensions acting upon all parts of the machine, and its unhappy occupants with the result (on the ship's company) that blood was forced violently fromthe head and stomach to the feet and legs. The effect on the physical and mental condition of the human body in these circumstances was far frompleasant, and it would be readily understood that while subjected to these distressing conditions it was difficult to keep a clear head and a steady hand.Quite recently, however, the observer's task bad been considerably lightened by the installing of an automatic observer, so that instead of jugglingfeverishly with a flock of instruments and gadgets, by means of which it is afterwards possible to trace the character of the spin from start to finish,he had nothing to do but operate the cinematograph camera switch. Spinning experiments on single seaters were, of course, a different matter.There was no room for half the instruments, and no observer to work them, so that the pilot was much more responsible for the results obtained. " Not,long ago," continued the lecturer, " a certain single-seater fighter used in the service was suspected of developing a stable state after a prolongedspin in the opposite direction to the rotation of the machine. Moreover, it was doubted whether recovery from the spin was possible after it hadreached the stable state. There appeared to be nothing for it but to try it out, and after it had been rendered as safe as possible the machine wastaken up to a height of 16,000 ft. to 18,000 ft. and spun. The safety-first modifications consisted of distributing the equivalent weight of the serviceload as far fore and aft as possible without disturbing the centre of gravity. Further precautions were taken to suable the pilot to abandon ship andtake to Bis parachute as quickly and as easily as possible in cases of extreme urgency. The side of the Cockpit on the inside of the spin was made insuch a manner that bj' a sharp nudge of the elbow a panel was detached and blown away leaving a gap large enough for the pilot to roll out. Handgrips were also fitted to the trailing edge of the centre section, and chocks of wood fitted to enable the feet to obtain a good purchase so that the pilotcould lift himself clear of the seat. In one of the tests the fitting of a modified tail unit caused the machine to spin at such a high rate of rotationthat it was quite impossible for the pilot to take any observations whatever after six or seven turns, and resulted in the machine becoming completelyout of control in a flat stable spin. After fighting with the controls from 18,000 ft. to about 7,000 ft., the pilot eventually succeeded in righting themachine by moving the throttle lever and control column violently back- wards and forwards together, thereby rocking the machine out of its stablestall in the stall. It was touch and go whether the pilot remained conscious long enough to bring the machine out of the spin. Several thousand feetbefore recovery he had lost sight of everything, and it took 20 minutes' gentle flying round the aerodrome before he was able to recover his physicaland mental condition enough to trust himself with a landing. With regard to abandoning an aircraft in a spin, the experiment wastried with complete success in a slow spinning two-seater, but on one occasion in the single-seater referred to above the pilot gave up all hope of recoveryand attempted to abandon ship, but by this time he was so nearly unconscious that he could see nothing, and found that he had not the strength to lifthimself out of his seat. Fate, however, was with him, arid a moment later he realised that the machine was no longer spinning, and when sight returnedto him, he discovered to his intense relief that he had not yet hit the ground, and it was. in fact, still several thousand feet away, even though it wasapparently above him. Wine; flutter, like spinning, was first discovered in actual flight, and severalpilots have had rather trying experiences, one coming down with his hands and the inside of his knees badly bruised by the central column with whichhe declared he had spent a hectic minute or so playing hide and seek round the cockpit. With regard to automatic controls, already the large aeroplanes of to-daywere becoming too much like hard work for one man to control the whole machine. The Servo-Rudder control had long been in use on large shipswhere the coxswain by turning the wheel operated a small engine, which in its turn moved the rudder. The principle had been adapted to aircraft,and coupled with these controls a box of tricks mainly consisting of gyro- scopes was being developed, which would enable the whole crew of theaircraft of the future (with the exception of the officer of the watch and his lookout) to return to the bar and let the machine keep its course by itself,righting itself in " bumps " and fetching up over its destination to scheduled time without its controls being so much as looked at from the time the machinewas taken off and set on its course. Amusing references were made by Capt. Hill at the conclusion of thelecture to the slide depicting an old B.E.9 machine with the observer's cockpit perched perilously in front of the propeller; Capt. Hill having vivid recollec-tions of his own experiences seated in that particular cockpit—and in con- clusion the lecturer was thanked very heartily on the proposition of FlightLieut. L. Paget, chief test pilot for the Westland Aircraft Works. m m m m AIR MINISTRY NOTICE TO GROUND ENGINEERS Index: 1920-1928 THE New Index has now been published giving (1) the Cancelled Notices,and (2) Operative Notices ; (3) Amendments. Any communications relating to this should be addressed to The Secretary (C.A.2), Air Ministry, Kingsway,London, W.C.2. (No. 5 of 1929) Irvin Parachutes in Demand 1 THE Irvin Air Chute of Great Britain Compaq's works at Letchworth, Herts, are being extended to cope with the orders for the Irvin Parachutes. We believe that the Irvin production rate will rise shortly from 35 per week to over 60 per week. " Al-Dur-Bra " Tubes CHARLES CLIFFORD AND SON, LTD., Fazeley Street Mills, Birmingham, have just issued a pamphlet on " Al-Dur-Bra " condenser tubes, which have shown great resistance to corro- sion and erosion, and are manufactured by the company. They can now be offered at a price little above that for ordinary " 70/30 " brass tubes. Change of AddressWE are asked to announce that Messrs. Aero Hire, Ltd., have now moved from Buckingham Gate, London, to ClarenceChambers, 39, Corporation Street, Birmingham. Telephone, Midland 4834). Inter Service RugbyTHE Inter Service Rugby matches this year will be played at Twickenham (at 3 p.m.) as follows—Feb. 16, R.A.F. v.Navy; March 2, Navy v. Army; March 23, R.A.F. v. Army. tt SI K K PUBLICATIONS RECEIVED Annual Report of the Board of Regents of the Smithsonian Institution for the Year Ending June 30, 1927. U.S. Govern- ment Printing Office, Washington, D.C., U.S.A. Price $ 1 -75. The Poetry Review. January—February, 1929. No. 1. Vol. XX. The Poetry Society (Incorporated), 16, Feather- stone Buildings, London, W.C.I. U.S. National Advisory Committee Reports : No. 287.— Theories of Flow Similitude. By A. F. Zahm. No. 289.— Forces on Elliptic Cvlinders in Uniform Air Stream. By A. F. Zahm, R. H. Smith, and F. A. Louden. No. 290.— Water-Pressure Distribution on a Seaplane Float. By F. L. Thompson. No. 291.-—Drag of C-Class Airship Hulls of Various Fineness Ratios. By A. F. Zahm, R. H. Smith, and F. A. Louden. No. 292.—Characteristics of Five Propellers in Flight. By J. W. Crowley, Jr., and R. E. Mixson. No. 308.—Aircraft Accidents : Method of Analysis. U.S. National Advisory Committee for Aeronautics, Washing- ton, D.C., U.S.A. Aviation : Isotta Fraschini's Contribution to Italian Avia- tion. Isotta Motors, Inc., 119, West 57th Street, New York, U.S.A. $ X K K AERONAUTICAL PATENT SPECIFICATIONS (Abbreviations : Cyl. = cylinder s i.e. •• Internal combustion i m. — motor.The numbers in brackets are those under which the Specifications will be printed and abridged, etc.) APPLIED FOR IN 1927Published February 7, 1929 26,777. P. SCHILOVSKY. Gyroscopic indicator. (303,817.)29,305. S. E. SAUNDERS and H. KNOWLER. Flying boats, seaplanes, etc. (303,946.)- APPLIED FOR IN 1928 Published February 7, 1929 1,836. IMPERIAL AIRWAYS, LTD., G. E. WOODS-HUMPHERY and H. L. HALL.Sparking-plugs for i.e. engines. (304,030.) 5,967. KOHRBACH METALL-FLUGZEUGBAU GES. Aerial screw-propellers.(285,925.) 10,081. F. CERUTTI. Screw-propellers. (288,299.) FLIGHT, The Aircraft Engineer and Airships 36, GREAT QUEEN STREET, KINGSWAY, W.C.2. Telephone: Holborn 3211. Telegraphic address : Truditur, Westcent, London. " FLIGHT " SUBSCRIPTION RATES.UNITED KINGDOM ABROAD* d. 7 2 4 3 6 12 Months, it Post Free. s. . 8 .16 .33 d. 3 6 0 5. 3 Months, Post Free.. 7 6 „ „ ..15 12 „ „ ..30 * Foreign subscriptions must be remitted in British currency. Cheques and Post Office Orders should be made payable to the Proprietors of " FLIGHT," 36, Great Queen Street, Kingsway, W.C.2, and crossed Westminster Bank. Should any difficulty bt experienced in procuring " FLIGHT " from local newsvendors, intending readers can obtain each issue direct from the Publishing Office, by forwarding rewM*nce as above. 110
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