B-17 Flying Fortress

B-17 Flying FortressThe B-17 Flying Fortress is one of the most famous airplanes ever built. The Army Air Forces first ordered the aircraft as a static test bed, but it was converted to a flight capable aircraft for testing supercharged engines. The converted aircraft was designated Y1B-17A and was one of a kind. The B-17 prototype flew on July 28, 1935, as Boeing Model 299. A variety of engine installations and configurations eventually led to the bottom-mounted turbo-supercharger which became standard on the B-17B — the first production model of the B-17 series of bombers.

A flight of B-17s enroute to Hawaii on Dec. 7, 1941 was assumed to be the large formation of aircraft tracked on radar early that Sunday morning. This formation turned out to be the carrier-based attack and fighter aircraft of Japan. The B-17s arrived later in the day and became the first B-17s to see combat in the Pacific Theater of Operations during World War II.

Few B-17s were in service on that infamous day, but production quickly accelerated. B-17s served in every World War II combat zone. The aircraft is best known for daylight strategic bombing of German industrial targets. The B-17E, the first mass-produced model Flying Fortress, carried nine machine guns and a 4,000-pound bomb load. It was several tons heavier than the prototypes and bristled with armament. It was the first Boeing airplane with the distinctive — and enormous — tail for improved control and stability during high-altitude bombing. Each version was more heavily armed.

The B-17G was the result of an almost continuous improvement program of earlier B-17 models. The -G model was basically the production version of the B-17F after the modifications and improvements were incorporated into the design. Although the Bendix chin turret is the most obvious improvement incorporated into the B-17G, it was actually first used on late model B-17Fs.

In the Pacific, the planes earned a deadly reputation with the Japanese, who dubbed them “four-engine fighters.” The Fortresses were also legendary for their ability to stay in the air after taking brutal poundings. They sometimes limped back to their bases with large chunks of the fuselage shot off.

There are many B-17 Flying Fortresses with famous histories, such as the “Hell’s Angels” and the “Memphis Belle.” These are just two of the B-17s that were pulled from front line service and flown back to the United States to conduct war bond tours. “Hell’s Angels,” a B-17F of the 358th Bomb Squadron, 303rd Bomb Group was one of the first aircraft to participate in a war bond tour. The aircraft completed 48 missions without ever turning back from its assigned target. The members of squadron got the idea to sign the “Hell’s Angels” before it left for the states. The idea caught on and other squadrons signed their aircraft before sending them back to the U.S.

The “Memphis Belle” has the distinction of being one of the first B-17s to complete 25 combat missions. It was also the first B-17 with 25 combat missions sent back to tour the U.S. to help sell war bonds. The aircraft was assigned to the 91st Bomb Group, 324th Bomb Squadron and based at Bassingbourn, England. The aircraft is one of the few B-17s remaining and is on display in Memphis, Tenn. A movie “Memphis Belle” is based on the crew’s missions.

Production ended in May 1945 and totaled 12,726. Boeing plants built a total of 6,981 B-17s in various models, and another 5,745 were built under a nationwide collaborative effort by Douglas and Lockheed (Vega). Only a few B-17s survive today; most were scrapped at the end of the war.

General Characteristics (B-17G)

  • Primary function: bomber
  • Length: 74 feet 9 inches
  • Height: 19 feet 1 inch
  • Weight: 65,500 pounds gross weight (actual – normal load)
  • Armament: Twelve .50-cal. machine guns and 8,000 pounds of bombs
  • Engines: Four Wright R-1820-97 turbo-supercharged radials of 1200 horsepower each
  • Maximum speed: 302 mph at 25,000 feet
  • Cruising speed: 160 mph
  • Service ceiling: 35,600 feet
  • Range: 3,400 miles (maximum ferry range)

Sources compiled from U.S. Air Force Museum and the Boeing Co. Article courtesy of Air Force Link.