The B-17 began operations in World War II with the
Royal Air Force (RAF) in 1941, and in the Southwest Pacific with the U.S. Army. During World War II, the B-17 equipped 32 overseas combat groups, inventory peaking in August 1944 at 4,574 USAAF aircraft worldwide. respectively.
RAF use AN529, with
He 111H-style "bathtub" ventral
gondola The RAF entered World War II without a sufficient supply of modern heavy bombers, with the largest available long-range medium bombers in any numbers being the
Vickers Wellington, which could carry of bombs. While the
Short Stirling and
Handley Page Halifax became its primary bombers by 1941, in early 1940, the RAF agreed with the U.S. Army Air Corps to acquire 20 B-17Cs, which were given the
service name Fortress Mk.I. Their first operation, against
Wilhelmshaven on 1941 was unsuccessful. By September, the RAF had lost eight B-17Cs in combat and had experienced numerous mechanical problems, and
Bomber Command abandoned daylight bombing raids using the Fortress I because of the aircraft's poor performance. The experience showed both the RAF and USAAF that the B-17C was not ready for combat, and that improved defenses, larger bomb loads, and more accurate bombing methods were required. However, the USAAF continued using the B-17 as a day bomber, despite misgivings by the RAF that attempts at daylight bombing would be ineffective.
Initial USAAF operations over Europe The air corps – renamed
United States Army Air Forces (USAAF) on 20 June 1941 – used the B-17 and other bombers to bomb from high altitudes with the aid of the then-secret
Norden bombsight, known as the "Blue Ox", which was an optical electromechanical gyrostabilized
analog computer. The device was able to determine, from variables put in by the bombardier, the point at which the bombs should be released to hit the target. The bombardier essentially took over flight control of the aircraft during the bomb run, maintaining a level altitude during the final moments before release. Two additional groups arrived in Britain at the same time, bringing with them the first B-17Fs, which served as the primary AAF heavy bomber fighting the Germans until September 1943. As the raids of the American bombing campaign grew in numbers and frequency, German interception efforts grew in strength (such as during the attempted bombing of Kiel on 13 June 1943 Operation Pointblank opened with attacks on targets in Western Europe. General
Ira C. Eaker and the Eighth Air Force placed highest priority on attacks on the German aircraft industry, especially fighter assembly plants, engine factories, and ball-bearing manufacturers. B-17s were used in early battles of the Pacific with little success, notably the
Battle of Coral Sea Five of the Japanese fighters strafing the B-17 aircrew were promptly engaged and shot down by three Lightnings, though these were also then lost. The allied fighter pilots claimed 15 Zeros destroyed, while the B-17 crews claimed five more. Actual Japanese fighter losses for the day were seven destroyed and three damaged. At their peak, 168 B-17 bombers were in the Pacific theater in September 1942, but already in mid-1942 Gen. Arnold had decided that the B-17 was unsuitable for the kind of operations required in the Pacific and made plans to replace all of the B-17s in the theater with B-24s (and later, B-29s) as soon as they became available. Although the conversion was not complete until mid-1943, B-17 combat operations in the Pacific theater came to an end after a little over a year. Surviving aircraft were reassigned to the 54th Troop Carrier Wing's special airdrop section and were used to drop supplies to ground forces operating in close contact with the enemy. Special airdrop B-17s supported Australian commandos operating near the Japanese stronghold at Rabaul, which had been the primary B-17 target in 1942 and early 1943. B-17s were still used in the Pacific later in the war, however, mainly in the
combat search and rescue role. A number of B-17Gs, redesignated B-17Hs and later SB-17Gs, were used in the Pacific during the final year of the war to carry and drop lifeboats to stranded bomber crews who had been shot down or crashed at sea. These aircraft were nicknamed
Dumbos, and remained in service for many years after the end of World War II.
Bomber defense over
Merseburg, Germany Before the advent of long-range
fighter escorts, B-17s had only their
.50 caliber M2 Browning machine guns to rely on for defense during the bombing runs over Europe. As the war intensified, Boeing used feedback from aircrews to improve each new variant with increased armament and armor.
Luftwaffe fighter pilots likened attacking a B-17 combat box formation to encountering a
fliegendes Stachelschwein, "flying porcupine", with dozens of machine guns in a combat box aimed at them from almost every direction. However, the use of this rigid formation meant that individual aircraft could not engage in evasive maneuvers: they had to fly constantly in a straight line, which made them vulnerable to German flak. Moreover, German fighter aircraft later developed the tactic of high-speed strafing passes rather than engaging with individual aircraft to inflict damage with minimum risk. The B-17 was noted for its ability to absorb battle damage, still reach its target and bring its crew home safely.
Luftwaffe attacks , Germany, on 1944; the bombardier was killed. After examining wrecked B-17s and B-24s, Luftwaffe officers discovered that on average it took about 20 hits with
20 mm shells fired from the rear to bring them down. During World War II approximately 40 B-17s were captured and refurbished by Germany after crash-landing or being forced down, with about a dozen put back into the air. Given German
Balkenkreuz national markings on their wings and fuselage sides, and
swastika tail fin–flashes, the captured B-17s were used to determine the B-17's vulnerabilities and to train German interceptor pilots in attack tactics. According to these allegations, the practice was initially successful, but Army Air Forces combat aircrews quickly developed and established standard procedures to first warn off, and then fire upon any "stranger" trying to join a group's formation. but they never saw combat. In 1946 (or 1947, according to Holm), the regiment was assigned to the
Kazan factory (moving from
Baranovichi) to help the Soviet effort to reproduce the more advanced
Boeing B-29 as the
Tupolev Tu-4.
Swiss-interned B-17s During the
Allied bomber offensive, some US and British bombers landed in Switzerland and were
interned. Some had been damaged and were unable to get back to Allied bases. Others flew into Swiss airspace due to navigation errors, and on rare occasions,
accidentally bombed Swiss cities. Swiss fighter aircraft intercepted such aircraft and sought to force them to land. In October 1943, a B-17F-25-VE (tail number 25841) developed engine trouble after a raid over Germany and was forced to land in Switzerland. The plane and its US flight crew were interned. The aircraft was turned over to the
Swiss Air Force, which flew the bomber until the end of the war, using other interned but non-airworthy B-17s for spare parts. The bomber's topside surfaces were repainted a dark
olive drab, but it retained its light gray underwing and lower fuselage surfaces. It carried the Swiss national white cross insignia in red squares on the topside and underside of its wings, and on both sides of its rudder and its fuselage, with the light gray flash letters "RD" and "I" on either side of the fuselage insignias.
Japanese-captured B-17s In 1942, Japanese technicians and mechanics rebuilt three damaged B-17s, one "D" and two "E" series, using parts salvaged from abandoned B-17 wrecks in the Philippines and the Java East Indies. The three bombers, which still contained their top-secret
Norden bombsights, were
ferried to Japan where they underwent extensive technical evaluation by the
Giken, the
Imperial Japanese Army Air Force's Air Technical Research Institute (
Koku Gijutsu Kenkyujo) at Tachikawa's air field. The "D" model, later deemed an obsolescent design, was used in Japanese training and propaganda films. The two "E"s were used to develop air combat tactics for use against B-17s; they were also used as enemy aircraft in pilot and crew training films. One of the two "E"s was photographed late in the war by US aerial recon. It was code-named "Tachikawa 105" after the mystery aircraft's wingspan () but not correctly identified as a captured B-17 until after the war. No traces of the three captured Flying Fortresses were ever found in Japan by
Allied occupation forces. The bombers were assumed either lost by various means or scrapped late in the war for their vital war materials. In 1946, surplus B-17s were chosen as
drone aircraft for atmospheric sampling during the
Operation Crossroads atomic bomb tests, being able to fly close to or even through the
mushroom clouds without endangering a crew. This led to more widespread conversion of B-17s as drones and drone control aircraft, both for further use in atomic testing and as targets for testing
surface-to-air and
air-to-air missiles. Perhaps the most famous B-17, the
Memphis Belle, has been restored – with the B-17D
The Swoose under way – to her World War II wartime appearance by the
National Museum of the United States Air Force at
Wright-Patterson Air Force Base, Ohio. In 1957 the surviving B-17s had been stripped of all weapons and painted black. One of these Taiwan-based B-17s was flown to
Clark Air Base in the Philippines in mid-September, assigned for covert missions into Tibet. On 28 May 1962, N809Z, piloted by Connie Seigrist and Douglas Price, flew Major James Smith, USAF and Lieutenant Leonard A. LeSchack, USNR to the abandoned Soviet arctic ice station NP 8, as
Operation Coldfeet. Smith and LeSchack parachuted from the B-17 and searched the station for several days. On 1 June, Seigrist and Price returned and picked up Smith and LeSchack using a
Fulton Skyhook system installed on the B-17. N809Z was used to perform a Skyhook pick up in the James Bond movie
Thunderball in 1965. This aircraft, now restored to its original B-17G configuration, was on display in the
Evergreen Aviation & Space Museum in
McMinnville, Oregon until it was sold to the
Collings Foundation in 2015. == Operators ==