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Aviation History
1951
1951 - 1110.PDF
First Aeronautical Weekly in the World r . , V and AIRCRAFT ENGINEER Founded 1909 No. 2212. Vol. LIX. FRIDAY, 15 JUNE 1951 j EDITORIAL DIRECTOR G. GEOFFREY SMITH, M.B.E. EDITOR MAURICE A. SMITH, D.F.C. ASSISTANT ED/TOR H. F. KING. M.B.E. TECHNICAL EDITOR C. B. BAILEY-WATSON, B.A. ART ED/TOR iOHN YOXALL ; • Editorial, Advertising and Publishing Offices: DORSET HOUSE, STAMFORD STREET, LONDON, S.E.1. ,.r^.. Telegrams, Flightpres, Sedist, London. Telephone, Woter/oo 3333 (60 lines). Branch Offices: : ..•.,_:• COVENTRY 8-10, Corporation Street. lekgrams, Autocar, Coventry. Telephone, Coventry 5210. BIRMINGHAM, 2 King Edward House, New Street. Telegrams, Autopress, Birmingham. Telephone, Mid/and 7191 (7 lines). MANCHESTER, 3 260, Deansgate. Telegrams, Mi/fe, Manchester. Telephone, B/ockfriars 4412 (3 lines). Deansgate 3595 (2 lines). GLASGOW, C.2. 26b, Renfield Street. Telegrams, Miffe, Glasgow. Telephone, Central 1265 (2 fines). SUBSCRIPTION RATES Home and Overseas: Twelve months O is. Od. U.S.A. and Canada, $10.00 BY AIR: To Canada and U.S.A., «x months, $16. IN THIS ISSUE: Labrador's Iron-ore Airlift 690 The Festival Air Races - 696 to Paris - - - 701 The Future Takes Shape 706 Engineering in Aviation;- 7II Birthday Honours - - 7I4 Hayload v. PayloadO F all the proverbs and fables about innocent little additions that make discon- certingly big sums, the classic is the one about the camel and the last straw. Had that proverbial beast appeared in Stamford Street and collapsed at our feet, we could have been little more surprised than we were recently on seeing the aggregate, in simple units, of the individually small demands which accessory equipment imposes on the primary power source of the modern aircraft. These particular straws, we reflected, may not actually break backs, but they certainly threaten seriously to reduce both performance and payload. It was Mr. F. M. Owner, in his lecture on The Application of Power to Aircraft (see page 711) who provided the revelation. Tabulating the demands of accessory-power systems, he estimated that an aircraft of 100 tons weight required no less than 1,150 h.p. to cover services including full anti-icing and undercarriage operation but excluding the galley and a small addition for brakes. If de-icing, as opposed to ice prevention, is considered sufficient, the total figure can be reduced considerably and cyclic de-icing permits reduction in the demands of the airscrew. A representative figure for a modern fbur-engined air-conditioned aircraft of 100,000 lb a.u.w. might be 250 h.p. One item included above, but not generally budgeted for, is that of power for flying controls—intermittent, but required several times a minute during flight. The need for powered controls on the majoiity of new high-speed aircraft is generally accepted, and up to 25 h.p. may have to be written off under this heading. Gas turbines—particularly of the Bristol type with free turbine—offer, it seems, better possibilities for tapping-off power, heat and pressure than do piston engines. It will be remembered that the Bristol company was, before the war, among the very first to adopt accessory gear boxes mounted away from a radial power unit. In American piston-engine practice it is still usual to hang the majority of accessories directly on the main unit. The pros and cons of auxiliary power units, particularly small gas turbines of low weight (though of high specific fuel-consumption) are discussed by Mr. Owner; duplication and weight are the chief penalties. One concludes that, while keeping an eye on their development, he does not yet favour their adoption. For the time being, then, the gas turbine will probably have to carry increasing numbers of straws on its back—and thus add a note of interrogation to the popular phrase "free as air". In fact, the pound of air required per person per minute in air- conditioned flight may alone represent less than 1 per cent of the gas turbine's mass flow; and assuming that pollution, such as by oil fumes, can be avoided (this is no simple matter, and rules out the use of methanol injection) the tapping-off of 1 per cent of compressor air means a penalty, according to Mr. Owner, of 1J per cent in power output and 2\ per cent in specific consumption. Emergency ServiceP URSUING its energetic campaign in support of the country's air defences, the Air League of the British Empire has issued a Memorandum on "An Air Wing for Civil Defence." The main purpose of such a unit would be to maintain com- munications should severe bombing—possibly atom bombing—destroy all surface communications. Natural disasters in many parts of the world have already indicated the valuable work to be done by light aircraft in similar circumstances. The sort of emergency for which the League seeks to prepare is such that accepted standards of aircraft operation would be set aside. The pilots would be gathered from ex-R.A.F. men who had passed rhe age limits for recall, and there would have to be a good deal of improvisation at bases and for servicing. Aid from the Services would of necessity be small, now or in wartime, because of their own many commitments. Simple, cheap and rugged light aircraft of the Auster type are almost certainly the sort for the job. We do not believe that ultra-lights of the kind mentioned in the Memoran- dum could do the work, even in fine weather. To be effective in emergency, a civil air wing of the type proposed should certainly be organized and exercised in peacetime.
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