COLD WEATHER FLYING

Timaru Herald, Volume CXLIII, Issue 20670, 8 March 1937, Page 13

COLD WEATHER FLYING

IMPORTANT TRIA 1 c IN CANADA EFFICIENCY OF BRITISH AIRCRAFT (From Our Own Correspondent) London, January 12. Cold weather flying trials of exceptional importance are beginning in Canada. They involve a British military aeroplane powered with one of the new sleeve-valved engines and fitted with enclosed cockpits similar to those embodied in the structure of new warplanes ordered for the Royal Air Force. The machine, a Hawker Hart biplane, was shipped to Canada towards the middle of last month It will be based at the Ottawa air station. Its pilots will be provided by the Royal Canadian Air Force. In all, the tests are scheduled to last six months. Much information has accrued from similar tests in the past. Warplanes must be fit for efficient operation in all extremes of climate and over all kinds of terrain. The various overseas Commands of the Royal Air Force provide ample opportunity for flying trials in tropical heat, but really cold weather within the Empire must be sought in Canada. In recent years, three types of aeroplane formerly in wide use in the Service—the Siskin fighter, the Wapiti “general purpose” aeroplane, and the Audax army co-operaticn craft—have gone through cold weather flying trials there. Power in the Audax is supplied by a Rolls-Royce Kestrel liquidcooled engine and the trials yielded invaluable data about the behaviour of the engine and its special ethyleneglycol coolant at temperatures ranging down to 47 degrees below Centigrade zero.

The Hart concerned in the present test has a Bristol Perseus sleeve-valved motor of the kind that will be in largescale production for the Royal Air Force within the next few months. A considerable first batch cf those engines is already being built; they arc scheduled for installation in a squadron of Vilde bees t “general purpose” biplanes and, experimentally, in other selected aircraft, of which the “(old weather” I-’art is one. The cockpits are heated by air previously circulated through metal muffs around the engine exhaust. This equipment will be rigorously tested in flights in the severest weather, while in the intervals the machine will be picketed in the open, its only extraneous protection against the elements being covers placed over the engine which are kept warm by a small heater lamp. Successful emergence from these trials—and even blizzards may test the staunchness of cockpit covers and engine installation—will mean elimb-a-tion of all. doubts about ability o’ the engine and cabin enclosures to withstand the coldest weather. Advance of Sleeve-valved Engines . PfodUdfi’cn. of a practical sleevevalved aero engine is a major triumph of British aeronautical engineering. The problems involved have baffled all other engine builders, and the British technician is nevz, after more than ten years of intensive research and development, in a position to use for the improvement of aeroplane performance the many advantages claimed for tne sleeve-valved engine. Chief among these advantages are higher efficiency and lower fuel consumption than the equivalent poppet-valved engine, longer “life” because of the smaller number of working parts, and simpler manufacture. Three main series of sleeve-valved engines have been announced up to the present: they are the Perseus, a 9-cylinder unit of which one present model develops up to 810 h.p., the Aquila, a smaller 9 -cylinder engine, and the Hercules, a 14-cylinder double-bank engine that was shown for the first time at the Paris aero show in November. The Hercules is the most powerful aero engine yet ordered in quantity by any government. In addition to military use, “civilrated” Perseus engines will shortly make their appearance in commercial aviation. Twenty-five of them—as exclusively stated in a previous message —will be installed in some of the Short four-engined monoplane boats which are going into service on Lhe Empire routes. Their behaviour in service is certain to provide informative data in comparison with the Pegasus Xc popptt-valved engines that power the boats already in commissicn.

Efficiency of Warplane Crews Enclosed cockpits have become essential to the comfort and efficiency of military aviators. Modern warplanes reach operational “ceilings” of 35 000 feet. The enormous recent increase of speeds made adequate pi election from the airstream imperative. Warmth and comfortable seating exert a profound effect on military efficiency which is especially merked on long bombing flights and other missions that demand several hours aloft at a time.