This B-17G-15-B0 was delivered without the additional nose guns that were added to early B-17Gs at modification centers. Note that the exhausts for inboard engines are on the outer sides of nacelles; exhausts on the outboard engines are on the bottoms of nacelles. Also note the camouflage pattern on engine cowlings.
HE Boeing B-17 Flying Fortress was one of the few U.S. warplanes to have an accepted name as well as a standard military designation before being named by the British or included on the U.S. government's list of so-called "popular" planes late in 1941.
The B-17, a daring design at the time, was developed in response to a U.S. Army fly-off competition for multi-engine bombers announced in 1934. "Multi-engine" at that time was generally understood to mean "twin engine." Boeing realized that all the contestants, using the available engines and state-of-the-art airframes, would perform similarly, so it decided to take a gamble: use four engines to improve the performance of its entry while carrying the same bomb load as the competition. Previously, additional engines had been used to get larger airplanes with heavier loads into the air, rather than to improve the performance of smaller airplanes.
Built as the company-owned Model 299, the prototype of the 12,726 B-17s that were eventually built rolled out of the factory in July 1935. The name "Flying Fortress" (later copyrighted by Boeing) was bestowed on it by a Seattle newspaper reporter who was impressed by the five defensive machine-gun turrets of the new bomber. The aircraft's name was a natural, owing to its armament and the fact that it was intended to defend the U.S. coastline from invading surface fleets accompanied by carrier-based fighters.
Model 299 ran away with the contest. Performance was sensational—a top speed of 236mph at a gross weight of 38,059 pounds; a cruising speed of 140mph; and a range of 3,101 miles. On October 30, an army pilot took off with the control locks inadvertently engaged. The crash eliminated the Boeing from the competition, but the Army was sufficiently impressed with it to order 13 nearly identical planes for service testing as the YB-17. At the Army's request, the engines were changed from 750hp Pratt & Whitney R-1690 Hornets to 850hp Wright R-1820 Cyclones. Shortly before the first flight on December 2,1936, the YB-17 designation was changed to Y1B-17.
The strength of an early Y1 B-17 was proven in a violent storm, so the Army directed that a fourteenth airframe, ordered for a static test, be completed as the single Y1B-17A flight article. Boeing used this to develop turbo-supercharger installations used on all subsequent B-17s for improved altitude capability.
Orders for 39 production B-17Bs trickled in over nearly three years, owing mostly to cost problems-Boeing's cost of building the planes in small numbers and the Army's reluctance to pay the price. Many officials thought that the B-17 was too much airplane for pilots to handle, and they urged that the money instead be spent on smaller bombers.
Thirty-eight B-17Cs and 42 B-17Ds were delivered through April 1941, thanks to the increasing urgency of the war situation. They resembled the Y1 B-17A, except for minor improvements and gradual upgrading of the armament installations, which had been designed according to out-of-date Army specifications. Armor was added, and fuel tanks were changed to the latest self-sealing type. The B-17D had 1,200hp R-1820-51 engines and a bomb load of 4,000 pounds at a gross weight of 47,242 pounds.
The combat inadequacies of the B-17 were revealed on 20
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