NEW BOMBERS

Evening Post, Volume CXXIV, Issue 13, 15 July 1937, Page 23

NEW BOMBERS

SPEED AND RANGE

279 M.P.H. MONOPLANE

(From "The Post's" Represontativ*.) LONDON, June 19. Enormous increase in striking power of the Royal Air Force is apparent in J official details of speed, range, and armament of new bombers which are now in production. Although the Air Ministry has lifted only partially the veil of secrecy over the performance of the new warplanes, sufficient is revealed to show that they challenge comparison with the best military aircraft of any other country. Two medium bombers and two heavy bombers are included in the list of craft admitted to wider publicity. The fastest of the group is the - twinengined Bristol Blenheim, which, according to official trials at the Royal Air Foree1 experimental landplane station at Martlesham Heath, reaches a level speed of 279 m.p.h. an hour, with full military load on board, at a height of 14,000 ft. This is the aeroplane which originated in a civil transport craft, called "Britain First," which was purchased by Lord Rothermere. Its performance on official test, in which it reached 268 m.p.h.—so m.p.h. faster than the best contemporary foreign commercial aeroplane—led the Air Ministry to ask for-a bomber version, and work that has culminated in contracts for several hundred Blenheims, to be fulfilled in a "shadow factory" as well as by the Bristol company itself, was begun. In the process the machine became a mid-wing monoplane, with the wings attached half-way up the fuselage, and other extensive changes were made to accommodate the military load. The Blenheim is built entirely of metal, with "stressed skin" covering of wings and fuselage. Power is supplied by two Mercury highly-supercharged engines, developing some 840 h.p. each. Controllablepitch airscrews improve take-off with heavy load, and operational cruising speed. At a height of 20,000 feet it can fly at no less than 274.5 m.p.h. and its service ceiling (where rate of climb has fallen to 100 feet a minute) is more than 30,000 feet. Fully laden, it weighs nearly 12,000 pounds, and its normal range in still air is approximately a thousand miles. Bomb-load may not be divulged. Defensive armament is carried in two gun stations, one in the nose and the other aft of the wings. Three men make up the crew. FASTEST SINGLE-ENGINED MEDIUM BOMBER. Equally notable for performance, when allowance is made for its lesser power, is the Fairey Battle singleengined medium bomber. Powered with a Rolls-Royce Merlin 990-1050 h.p. liquid-cooled engine, it is officially credited with a level speed of 257 m.p.h. at a height of 15,000 feet. Its normal laden weight is nearly 11,0001b and range, with exceptionally heavy bomb-load for a single-engined craft, about a thousand miles, which is considerably augmented when the aeroplane carries the overload of fuel for which it was designed. The service ceiling of the Battle is approximately 26,000 feet. Metal stressed skin construction is employed. The Merlin engine is cooled by an ethylenegycol mixture. Each of the heavy bombers —the Armstrong Whitworth Whitley and the Handley Page Harrow —is capable of maximum level speed of approximately 200 miles an hour. The heavier of the two is the Harrow, which flies normally at a weight of 23,5001b and carries a bigger bomb-load than any earlier British aeroplane. Normal cruising speed, on the power of two Bristol air-cooled engines, is 163 m.p.h, at a height of 15,000 feet. The range with full bomb-load is 1250 miles, which may be extended by overload and adjustment of armament earned to 1840 miles. "SECTIONISED" MANUFACTURE. Harrow monoplanes are flowing rapidly through the company's factory, thanks to the adoption of clever quantity production methods which have reduced enormously the time needed to build big aeroplanes. The Harrow production system aims at fitting the work to the worker. Sub-assemblies oC parts are so planned that crowding at any one job is eliminated and every operative can do his set task with plenty of room to move. Congestion is avoided, while the almost complete substitution of jig gauges for blueprint drawings greatly accelerates all manufacturing processes. The Whitley bomber, powered with two Siddeley Tiger engines, is a mid-' wing monoplane with retractile undercarriage. Its normal range, with a useful load of nearly 70001b, is 1500 miles. It has a monocque metal fuselage, with stressed-skin covering. Enclosed gun turrets are located at nose, tail, and amidships. The tail turret is manually operated, and embodies an ingenious trapdoor so that the gunner may leave the machine with his parachute in emergency. The trapdoor is about the size of a dustbin lid, and is on the underside of the turret, facing the rear. A spring-loaded catch with a big hand-ring closes it. If the gunner is obliged to jump, all he has to do is to pull on the catch, when he falls out of the aeroplane.