B-17 Flying Fortress

Boeing · United States · first flew 1935 · bomber

The Boeing B-17 Flying Fortress is a four-engine American heavy bomber, famed for its heavy defensive armament and its role in the daylight strategic bombing of occupied Europe.

Recognition (WEFT)

W — Wings	Low-mounted, tapered
E — Engines	4 × piston, wing-mounted
F — Fuselage	22.66 m fuselage
T — Tail	Conventional

WEFT is AircraftIQ's four-point recognition method — how it works.

Spot it by:

Four radial engines on a tapered wing
Tall single fin with large dorsal fillet
Glazed framed nose and waist gun positions

Look for four radial engines on a broad tapered wing and a tall single fin with a long dorsal fillet. The framed, glazed nose and the bulged waist gun windows confirm the Fortress.

Specifications

The B-17 Flying Fortress has a length of 22.66 m (74 ft).
It has a wingspan of 31.62 m (104 ft).
Its maximum speed is 462 km/h (287 mph).
Typical crew: 10.

Figures are for the representative variant described above; marks differ. See how AircraftIQ sources figures.

History

The Model 299 prototype first flew in 1935 and the type matured through wartime into the heavily armed B-17G. Its name came from the array of machine guns bristling from the fuselage. Around 12,700 were built.

Variants

The definitive B-17G added a chin turret to counter head-on attacks, with thirteen .50-calibre guns in total. Earlier B-17E and F models established the layout. Some served in maritime patrol and air-sea rescue roles.

Where you'll see it

B-17s of the US Eighth Air Force flew from numerous bases across eastern England, and the type is central to the American Air Museum at IWM Duxford, which displays the preserved 'Mary Alice'. The airworthy 'Sally B' is UK-based and a regular airshow performer. It is woven into the wartime history of East Anglia.

In depth

The name 'Flying Fortress' was coined not by Boeing's marketing department but by a Seattle Times reporter, Richard Smith, who watched the bristling prototype taxi out on 17 July 1935 and wrote that it looked like 'a 15-ton flying fortress.' Boeing liked the phrase enough to trademark it. The Model 299 prototype then crashed on its second evaluation flight when a crew member forgot to remove gust locks from the control surfaces before takeoff — an oversight that killed both pilots and nearly ended the program before it began. The Army Air Corps, impressed by the aircraft's performance on its maiden flight, ordered thirteen YB-17 service-test examples despite the crash, a rare act of institutional faith that determined the course of American strategic bombing.

The B-17's defensive gunnery doctrine — tight box formations creating overlapping fields of fire — was tested against hard reality over Europe. The 'Bloody Hundredth' (100th Bomb Group) became the most famous casualty: three missions in early October 1943 cost it nearly two thirds of its crews, and it never fully recovered its strength. The theoretical Norden bombsight accuracy of 'a bomb in a pickle barrel from 20,000 feet' was achieved only in ideal laboratory conditions; in combat, with flak, fighters, cold, oxygen problems and windage errors, the Circular Error Probable of a combat formation was measured in hundreds of yards. The shift to radar bombing in overcast conditions made precision a further abstraction.

Crew survival statistics were brutal. In the peak loss period of mid-1943 before long-range escort fighters became available, a combat airman's statistical chance of completing a 25-mission tour without being killed, wounded or taken prisoner was approximately one in four. The 8th Air Force erected rest facilities in England patterned on the USO model, and the term 'flak happy' — combat fatigue precipitated by sustained exposure to anti-aircraft fire — entered the military lexicon largely through B-17 crew experiences.

The aircraft's defensive armament evolved through the war in direct response to Luftwaffe attack profiles. The Luftwaffe discovered that head-on attacks from twelve o'clock level offered the most vulnerable approach angle — the early models carried only a single hand-held .30 calibre gun in the nose. The B-17G's chin turret, introduced in 1943, was a direct response and added two power-driven .50 calibre guns pointing forward. The final armament of thirteen .50 calibre guns gave the G model its fortress identity in fact as well as name.

A total of 12,731 B-17s were built. Approximately 45 survive in complete or restorable form worldwide, with roughly a dozen maintained in airworthy condition in the United States. In the UK, 'Sally B' (serial 44-85784) is the sole flying B-17 in Europe and has been based at IWM Duxford since 1975, supported by the B-17 Preservation charity. She appears annually at the Duxford airshow season and was used in the 1990 film 'Memphis Belle.' The American Air Museum at Duxford, designed by Norman Foster and opened in 1997, houses the B-17G 'Mary Alice' suspended from the ceiling alongside other Eighth Air Force types — one of the most atmospheric aircraft-museum spaces in Britain. The National Museum of the USAF at Dayton, Ohio, holds three complete B-17s, the largest single-site collection.

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