Mass -Production of Fairey Battle, Bombers: Canada's Huge Traffic an From Our Own Aviation CORRESPONDENT
London, June 12.
Glimpses of what the capacity of British aeroplane manufacturing now is were obtainable this week when, in conjunction with the opening of a new assembly shed, the Fairey aviation works at Stockport were opened to inspection, Here in a continuous stream are being produced numbers of the new Fairey Battle medium bombers,- be-Jieved to be the fastest single engine bombers ever supplied to, the R.A.F. They are fitted with 1,000 h.p. Rolls Royce Merlin engines, and are of all metal construction, with retractable under carriages, wing flaps, variable-pitch airscrews, and every conceive able instrument necessary to aid the pilot, Their mancuvring qualities are almost miraculous, But perhaps the most impressive part of the display was the ingenuity in planning which has made it possible to turn out such numbers of aeroplanes as it were by mass production, How many Battles have been ordered is a secret, but there were 300 under construction in the works, so arranged that as part of One is finished, another instantly takes its place. With this, the most extreme care has been taken to ensure accuracy, the result. being that each, machine is as perfect as if It had been singly built, The Merlin's Power Details now available of the first performances of the Merlin engine just mentioned are very impressive. It is a liquid-cooled 12-cylinder fully supercharged engine, planned to operate with variable-pitch airscrews, both with the British constant speed airscrews that provide nearly ideal running conditions for the engine. Provision is made for tapping the lubricating oil system to provide hydraulic power needed to turn the airscrew blades, Statistics given out by the Air Ministry show that the international power rating of the Merlin is 990 h.p: (1004 c. v) at 12000 feet, and its maximum output 1,050 lip. Net dry weight of the engine is 1,318% 1b. and its weight/power ratio, therefore, is only 125 1b./h.p. at normal maximum output—an extremely low figure for a liquid-cooled engine designed for the long service and iroublefree running that are characteristic of British aero engines. Its total cylindrical capacity is 27 litres, Which means that the engine at full power turns out nearly 40 lip. per litre. It is odeled by ethylene-glycol, a mixture which enables engines to run at temperatures considerably higher than that of boiling water, and thereby to perform more eficiently. Further, a smaller quantity of the mixture is required for effective cooling than in the equivalent water-cooled engine, with consequent saving in head, resistance and weight. Merlin engines in the new warplanes are designed'4o work with "ducted" radiators, the British invention that has markedly lessened the head resistance of powerful engines, '27, '29 and '31, when he competed against the pick of the world and beat them. His Supermarine mono-[planes were in their day the fastest vehicles in the world, and the new Supermarine Spitfire is also his design.
Mr. Mitchell was a' quiet, retiring man, who would hesitate to offer an opinion even about the problems of design of which he knew more than most people, He was extraordinarily quick and resourceful, as an anecdote related by the "Morning Post" will show. It was during the trials for the Schneider Trophy, and one new machine, during a test when the speed had for the first time been forced up to the maximum, developed wing flutter, and the pilot made a forced landing. At that time the knowledge of wing flutter was negligible. It was the most dreaded trouble of all It seemed to those who knew the secret of what had happened to that machine, that the British chances of winning the race "were shattered. But Mr. Mitchell devised a solution to the problem almost by the same evening.
Mr, Mitchell was born at Stoke-on-Trent and apprenticed to Messrs. Kerr Stuart & Ca, to which firm he became later on the assistant engineer. Besides small racing seaplanes and faster single-seater fighters, he was also most successful designing large flying-boats. He joined the Vickers Supermarine Aviation Works in 1916 and in 1920, when only 25 years old was appointed its chief engineer and designer. Subsequently he became a director ct the firm.
Text read from the printed page and cleaned; old type leaves the occasional error.