B-17

B-17
Name	B-17
Type	Heavy bomber
Manufacturer	Boeing
Designer	E. Gifford Emery, Edward Curtis Wells
First flight	28 July 1935
Introduction	April 1938
Retired	1968 (Brazilian Air Force)
Primary user	United States Army Air Forces
Number built	12,731
Unit cost	$238,329
Developed into	Boeing 307 Stratoliner

B-17. The Boeing B-17 Flying Fortress is a four-engined heavy bomber developed in the 1930s for the United States Army Air Corps (USAAC). It became the iconic strategic bomber of the United States Army Air Forces (USAAF) in the European theater of World War II, renowned for its durability and defensive firepower. The aircraft served in every World War II combat zone and was central to the Combined Bomber Offensive against Nazi Germany.

Development and design

The B-17 originated from a 1934 United States Army Air Corps specification for a multi-engine coastal defense bomber. A team led by E. Gifford Emery and Edward Curtis Wells at Boeing developed the Model 299, which first flew in 1935. Early testing, including a crash at Wright Field, led to significant redesigns, resulting in the B-17B model which introduced a larger rudder and redesigned nose. The definitive design featured a mid-wing monoplane configuration with four Wright R-1820 radial engines and a distinctive large tail fin. Its robust construction, incorporating a semi-monocoque fuselage and multiple General Electric-powered gun turrets, earned it the "Flying Fortress" nickname. Key production was expanded through the World War II-era War Department's "Project A" and involved manufacturing by Douglas Aircraft Company and Lockheed Corporation under the Boeing-led BVD (Boeing-Vega-Douglas) pool.

Operational history

The B-17 first saw combat with the Royal Air Force in 1941, but found its primary role with the USAAF's Eighth Air Force based in the United Kingdom. It was the backbone of the Combined Bomber Offensive, conducting high-altitude daylight precision bombing raids against strategic targets in Occupied Europe and Germany itself, such as the Schweinfurt–Regensburg mission and Ploiești oil refineries. The aircraft suffered heavy losses until the introduction of long-range fighter escorts like the P-51 Mustang. B-17s also served in the Pacific theater with the Fifth Air Force and in the Mediterranean theater with the Fifteenth Air Force. Notable units included the 91st Bombardment Group and the 100th Bombardment Group. Post-war, many were used for air-sea rescue, reconnaissance, and as QB-17 target drones.

Variants

The initial production model was the B-17B, followed by the B-17C and B-17D with improved armament. The B-17E introduced a completely new rear fuselage with a Cheyenne turret and a larger tail, defining the aircraft's classic silhouette. The B-17F standardized the design with a frameless plexiglass nose. The final and most-produced variant was the B-17G, which featured a Bendix-designed "chin turret" to counter head-on attacks. Specialized variants included the F-9 photographic reconnaissance version, the XB-40 "gunship" escort, and the CB-17 cargo transport. The Boeing 307 Stratoliner commercial airliner was a direct derivative.

Operators

The primary operator was the United States Army Air Forces, with subsequent service in the United States Air Force after 1947. During World War II, it was supplied to the Royal Air Force under Lend-Lease, though the RAF Bomber Command largely favored the Avro Lancaster for night operations. Post-war operators included the Brazilian Air Force, the French Air Force, the Israeli Air Force, and the Dominican Air Force. Several were also used by the Central Intelligence Agency for covert operations.

Specifications (B-17G)

* **Crew:** 10 (Pilot, co-pilot, bombardier, navigator, radio operator, flight engineer, ball turret gunner, two waist gunners, tail gunner) * **Length:** 74 ft 4 in (22.66 m) * **Wingspan:** 103 ft 9 in (31.62 m) * **Height:** 19 ft 1 in (5.82 m) * **Empty weight:** 36,135 lb (16,391 kg) * **Powerplant:** 4 × Wright R-1820-97 "Cyclone" turbosupercharged radial engines * **Maximum speed:** 287 mph (462 km/h) * **Range:** 2,000 mi (3,200 km) with 6,000 lb (2,700 kg) bomb load * **Service ceiling:** 35,600 ft (10,850 m) * **Armament:** 13 × M2 Browning machine guns; up to 9,600 lb (4,350 kg) of bombs internally

Cultural impact

The B-17 became an enduring symbol of American industrial might and the air power doctrine during World War II. It was heavily featured in wartime propaganda and Office of War Information films, as well as post-war movies like Twelve O'Clock High and *Memphis Belle*. The aircraft is a centerpiece of museums worldwide, including the National Museum of the United States Air Force and the Imperial War Museum Duxford. The stories of crews from units like the Bloody Hundredth have been immortalized in literature and television, such as the miniseries Masters of the Air. Surviving airframes, like the *Shoo Shoo Shoo Baby* and *Aluminum Overcast*, remain popular attractions at airshows.

Category:United States bomber aircraft 1930–1939 Category:World War II American bombers Category:Four-engined aircraft