GIANT BOMBERS

New Zealand Herald, Volume LXXVIII, Issue 23859, 9 January 1941, Page 9

GIANT BOMBERS

AMERICAN MACHINES THE "FLYING FORTRESS" NEW MONSTER BUILDING [from Ot'R OWN" correspondent] LOXDON, Dec. 10 Size is a quality inevitably associated with transatlantic productions, and reports of new American bombers either ordered by Britain or for the United States air services feature their size as an outstanding point, says the London Times. One type of big American bomber which has caught the imagination is the Boeing 817, sometimes called tiie "Flying Fortress." Actually, as big four-engined aircraft go, it is not unusually large. Its general dimensions and range correspond to those of Britain's 20-ton, four-engined flyingboat the Short Sunderland, its wing span of 105 ft. is eight feet less than that of the Sunderland. It is some 18ft. less than the span of the Arm-strong-Whitworth Ensign. Britain's biggest civil air liner, also a iourengined aircraft.

As first produced some few years ago the original "Flying Fortress" had four 1000 horse-power Wright Cyclone engines, which gave it a maximum speed of about 250 miles per hour. The effective range claimed was around 8000 miles —say from London to Tripoli and back —and the service ceiling just under six miles. Bomb load is a variable factor, dependent among other things, on the amount of fuel carried. But it is safe to assume that the 817 could carry four to five tons of bombs and ammunition on a round trip of 2000 miles.

A feature of the design which gave the Hl7 the name of "Flying Fortress" is the number of protective gun positions. Four of these were originally located in "blisters" on the outside of the fuselage, but later examples show gun turrets similar to the British practice. Even so. the total gun power is not likely to approach that possessed by the latest versions of Britain's famous bombers, such as the turreted Wellington. An improved "Flying Fortress," produced just before the war, had a cleaned-up externa] design and a special supercharging system for giving greater engine power at heights above

20,000 ft. The resulting performance figures were not made known, but it may be assumed that the maximum speed of 250 miles per hour has been improved upon. A ueiv bomber now being built by the I nited States is in a different category, and so far as is known really is the "world's largest." This is the Douglas 819. a 00-ton monster with a wing span of 210 ft.—three times that of the Hand ley-I'a ire Hampden. Four Wright Duplex-Cyclone engines, each of 1700 horse-power, are calculated to give this new Douglas bomber a speed of "over 200 miles per hour." The estimated range is 6000 miles, roughly the distance from New York to Southampton and back. A '"useful load" of 28 tons is quoted, including about 18 tons oi bombs. Such a bomb load represents about as much as could be carried, for a much shorter distance, by six entire squadrons of Me 109 fighterbombers. The landing gear is of the threewheel or tricycle type, and a feature of the design is the provision of heated and air-conditioned cabins and sleeping quarters for the crew of 10. Soundproofing, a practice usually associated only with modern civil air liner construction, but important from the pointof view of flying fatigue, has also been provided in the radio operator's and navigator's compartments.