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Aviation History
1950
1950 - 0261.PDF
gLIGHT, 2 February 1950 #OWER-ASSISTED CONTROLS . : : left spools of the servo piston is also connected to the further-most area of the servo cylinder. With this connection, and a similar connection of the opposite end of the booster cylinderto the opposite end of the servo cylinder, any differential pressure existing between the two ends of the booster cylinderalso exists at the two ends of the servo cylinder. A unique control lock is incorporated in the by-pass valvewhereby it is possible, by inserting a key, to turn the valve and so trap oil 011 each side ofthe booster piston. The lockingarrangement is such that the necessary key is not available for use in the lock valve until a locking-block has been installedin the cockpit control element. Conclusions.—Although we have confined ourselves to a con-sideration of hydraulically operated servo controls, this should not lie construed to imply the impracticability of any otherpower medium. Electrically energized systems have been devel- oped, but have been found lacking in one or other of thepreviously defined essential characteristics. Electricity is the only alternative form of energy available, and an all-electricsystem may yet be evolved which will satisfy all requirements. Against this, however, it must be realized that the case iorhydraulics is based entirely on one of its inherent physical properties, namely, its ability to absorb and transmit pressure.As a relatively incompressible fluid, hydraulic oil is particu- larly well-suited to the transmission of powerful rotary or linearmovement over any distance. It is particularly significant that the mere application of thisfundamental property has been found to be the most satisfac- tory solution for power-assisted flying control systems and theirassociated problems. Hydraulic power is no panacea, however. For remote control over long distances electric operation is un-equalled, and an electro-hydraulic system combining hydraulic actuation with remote electrical control may constitute the.penultimate state of development. Failing electrical remote control, the purely hydraulic servo-control system tends notonly to be heavy and complicated, but also introduces other- wise avoidable servicing difficulties. yuite apart from itsremote-control propensities, electric energy has another very important attribute. We have seen that, in the case of theVickers system in the Martin Mars (as well as with other installations), the use of an electrically driven hydraulic pumpensures complete reliability even in the event of main engine failure. It is, perhaps, also relevant briefly to comment upon themanner in which hydraulic fluids have been rendered almost impervious to temperature-changes over the stipulated wideranges now prevalent. The usefulness of an hydraulic fluid is determined largely by its viscosity-temperature behaviour. Ailfluids show some change in viscosity with changing tempera- tures, but no series of organic liquids is as nearly constant inviscosity over so wide a temperature range as are the silicone fluids. The methyl-silicone fluids are clear, odourless liquids.In contrast to the petroleum oils, they are only about 40 per cent organic. No doubt, their inorganic core of silicone andoxygen is responsible for their unusual properties, among which is low viscosity-change per unit change in temperature—thelowest, in fact, of any known liquid. This chemical structure is also responsible for their stable viscosity-temperaturebehaviour, shear resistance, and oxidation and heat-resistance. These properties, coupled with their extremely low freezingpoints, make them particularly useful in aircraft hydraulic svstems. ABOUT AVIATION IN N.Z. aviation is a very considerable force in the economicJ- life of New Zealand—far more ' so than anybody not iamiliixr with the Dominion would expect—is apparent fromeven a quick glance at White's Air Directory and Who's Who in Mew Zealand Aviation.* Published annually, this 170-pageguide (which embraces every aspect of civil and Service aviation in the area) should be of value to firms in this country whodo business in the area, or to executives contemplating a visit. * Published at js dd by White's Aviation, Ltd., Pilworlh Building. Auckland. New Zealand. TRAINING FOR THE INDUSTRY ALL education officers of firms in the aircraft industry,particularly in the London area, will be interested in areport. Education for Aeronautical Engineering, which reviews the present capacity for aeronautical technical training in aiid around the metropolis It is published at is by the Regional Advisory Council for Higher Technological Education (London and Home Counties), 20, Fitzroy Square, London, W.i. The report, which concerns educational authorities only, is not intended for the use of prospective trainees. COMMEMORATING ACHIEVEMENT IN collaboration with Josiah Wedgwood and Sons, ShortBrothers and Harland, Ltd., are annually having 500 medallions struck, carrying the portrait of an aviator whose achievements have advanced the cause of aeronautics,, and these medallions will be sent to overseas clients of the firm. They are about 5111 high, and the portraits are modelled in bas - relief by Arnold Machin, A.R.A. The sub- stance used—"Jasper" was discovered by Josiah Wedgwood in 1774, and since that time it has been used for portrait-medallions of distinguished people. Sir John Alcock and Sir Arthur Whitten Brown, who ".made the first trans-Atlantic flight, have already been ' •featured in this series. Sir ''Keith Smith has been chosen as the subject for medalion No. 3. Recently, Rear-Admiral S lattery, managing director of Shorts, The medallioi^ bear\h^Che-^oli<-^1*gave Sir Keith the oppor- trait of Sir Arthur Whitten tunity of examining Arnold Brown, pioneer Atlantic pilot. Machin's wax prototype. A TEST PILOT'S RECORD MR. VV. H. SUTCLIFFE, export sales manager of Dunlop'saviation division, has just completed 10,000 flying hours He first flew 33 years ago. During 11 years of Service flyinghis duties included those of instruction at Netheravon. He holds a Master Flying Instructor's Certificate, and for 12 yearsbefore the war he was chief instructor and secretary of the Midland Aero Club. During the war he was a test pilot, first with Rolls-Royce,then with the Lockheed Aircraft Corporation, for whom he tested aircraft after their reassembly in England. He thenbecame chief test pilot to Dunlop. Two years ago, as their export sales manager, he flew 21,073 miles on a tour of SouthAmerica He has also toured India, Ceylon, Egypt, Greece, Turkey, France, the Benelux countries, Scandinavia, Canadaand America Feb t-eb feb feb. feb feb 'eb. feb Feb. Feb Feb Feb March March March March March March March March March March 3. 4. 8 9. H. 17. 21 21 22. 22. 23. 25 1. 1. 2. A. 7. 8. 14. 15. 16. 17. FORTHCOMING EVENTS R.A.F Reserves Club : Annua. Bail, Dorchester Hotel. London. Rritish Interplanetary Society r Discussion—" Effects o Interplanetary Flight." . R. Ae. S. (Brough): " Rocket Propulsion and Inter-Planetary Right," by A. V. Cleaver. A. R Ae. S. R.Ae.S. : " Producing a Prototype Aircraft by C T Wilkins, A.F.R.Ae.S. P.Ae.S. Section Lecture : " Prototype Testing," by D. R. H. Dickinson, A.F.R.Ae.S. institute of Navigation : " Air Traffic Control," a symposium of papers. R.Ae.S. (Belfast) : " Strength-testing of Aircraft " bv Dr. P. B. Walker, M.A., Ph.D., F.R.Ae.S. R.Ae.S. Section Lecture : " Air-Intake Deiign for High-speed A^craft," by Dr. 1. Seddon. B.Sc. R.Ae.S. (Preston): " Radar and the Aircraft which Use it " by B. W. Hodlin, B.Sc. R.Ae.S. (Reading) : " Propeller Turbines," by A. C. Clinton F.R.Ae.S. R.Ae.S. Graduates : " Problems of Heat Transfer," by W. R. Shapey, B.Sc.. Grad. R.Ae.S., and J. Rivers, Grad. R.Ae.S. Helicopter Association : ** French Helicopter Development " by Col. R. M. Garry. R.Ae.S. (Weybridge) : " Do Scientists Know Anything »' by C. G. Grey, F.M.R.Ae.S. R.Ae.S. Graduates : " Engineering Problems of Aircraf Design." (Joint meeting with I.E.E. and I.M.E. graduates.) R.Ae.S. : " Design for Maintenance," by R. G. Bishop F.R.Ae.S. British Interplanetary Society : " Testing of Rocket Motors," by Dipl. Ing. H. F. Zumpe. R.Ae.S. Graduaces : "Gas-turbine Installation," by J C Wallin, B.Sc. A.F.R.Ae.S. R.Ae.C. : Ball, Londonderry House. R.Ae.S. (Belfast) : " Problems of High-speed Flight," by H. Davies, M.Sc, F.R.Ae.S. R.Ae.S. (Preston): Lecturettes by Branch Members. R.Ae.S. : "Air Survey," by G/C. F. C. V. Laws, C.B., C.B.E. Institute of Transport : Annual Dinner.
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