The Boeing B-17 Flying Fortress is a four-engine heavy bomber aircraft developed for the United States Army Air Corps (USAAC). Competing against Douglas and Martin for a contract to build 200 bombers, the Boeing entry outperformed both the other competitors and more than met the Air Corps' expectations. Although Boeing lost the contract due to the prototype's crash, the Air Corps was so impressed with Boeing's design that they ordered 13 B-17s. The B-17 Flying Fortress went on to enter full-scale production and was considered the first truly mass-produced large aircraft, eventually evolving through numerous design advancements.
The B-17 was primarily employed in the daylight precision strategic bombing campaign of World War II against German industrial, civilian and military targets. The United States Eighth Air Force based in England and the Fifteenth Air Force based in Italy complemented the RAF Bomber Command's nighttime area bombing in Operation Pointblank, to help secure air superiority over the cities, factories and battlefields of Western Europe in preparation for Operation Overlord. The B-17 also participated, to a lesser extent, in the War in the Pacific, where it conducted raids against Japanese shipping.
From its pre-war inception, the USAAC touted the aircraft as a strategic weapon; it was a potent, high-flying, long-ranging bomber capable of unleashing great destruction yet able to defend itself. With the ability to return home despite extensive battle damage, its durability, especially in belly-landings and ditchings, quickly took on mythic proportions. Stories and photos of B-17s surviving battle damage widely circulated, boosting its iconic status. Despite an inferior range and bombload compared to the more numerous B-24 Liberator, a survey of Eighth Air Force crews showed a much higher rate of satisfaction in the B-17. With a service ceiling greater than any of its Allied contemporaries, the B-17 established itself as a superb weapons system, dropping more bombs than any other U.S. aircraft in World War II. Of the 1.5 million tonnes of bombs dropped on Germany by U.S. aircraft, 500,000 were dropped from B-17s.
On 8 August 1934, the U.S. Army Air Corps (USAAC) tendered a proposal for a multi-engined bomber to replace the Martin B-10. Requirements were that it would carry a "useful bombload" at an altitude of 10,000 ft (3 km) for ten hours with a top speed of at least 200 mph (320 km/h). They also desired, but did not require, a range of 2,000 miles (3200 km) and a speed of 250 mph (400 km/h). The Air Corps were looking for a bomber capable of reinforcing the air forces in Hawaii, Panama, and Alaska. The competition would be decided by a "fly-off" at Wright Field in Dayton, Ohio. Boeing competed with the Douglas DB-1 and Martin Model 146 for the Air Corps contract.
The prototype B-17, designated Model 299, was designed by a team of engineers led by E. Gifford Emery and Edward Curtis Wells and built at Boeing's own expense. It combined features of the experimental Boeing XB-15 bomber with the Boeing 247 transport airplane. The B-17 was armed with bombs (up to 4,800 pounds (2200 kg) on two racks in the bomb bay behind the cockpit) and five 0.30 inch (7.62 mm) caliber machine guns, and was powered by Pratt & Whitney R-1690 radial engines each producing 750 horsepower (600 kW) at 7,000 ft (2100 m).
The first flight of the Model 299 was on 28 July 1935, with Boeing chief test-pilot Les Tower at the controls. Richard Williams, a reporter for the Seattle Times coined the name "Flying Fortress" when the Model 299 was rolled out, bristling with multiple machine gun installations. Boeing was quick to see the value of the name and had it trademarked for use. On 20 August, the prototype flew from Seattle to Wright Field in nine hours and three minutes at an average speed of 235 mph (378 km/h), much faster than the competition.
At the fly-off, the four-engine Boeing design displayed superior performance over the twin-engine DB-1 and Model 146, and General Frank Maxwell Andrews of the GHQ Air Force believed that the long-range capabilities of four-engine large aircraft were more efficient than shorter-ranged twin-engined airplanes. His opinions were shared by the Air Corps procurement officers and, even before the competition was finished, they suggested buying 65 B-17s.
Development continued on the Boeing Model 299, and on 30 October 1935, the Army Air Corps test-pilot, Maj. Ployer Peter Hill, and Boeing employee Les Tower, took the Model 299 on a second evaluation flight. The crew forgot to disengage the airplane's "gust lock," a device that held the bomber's movable control surfaces in place while the plane was parked on the ground, and having taken off, the aircraft entered a steep climb, stalled, nosed over and crashed, killing Hill and Tower (other observers survived with injuries). The crashed Model 299 could not finish the evaluation, and while the Air Corps was still enthusiastic about the aircraft's potential, Army officials were daunted by the much greater expense per aircraft. "The loss was not total, however, since the fuselage aft of the wing was intact, and the Wright Field Armament section was able to use it in subsequent gun mount development work, but Boeing's hopes for a substantial bomber contract were dashed." Army Chief of Staff Malin Craig cancelled the order for 67 B-17s, and ordered 133 of the twin-engine Douglas B-18 Bolo instead.
Regardless, the USAAC had been impressed by the prototype's performance and, on 17 January 1936, the Air Corps ordered, through a legal loophole, 13 YB-17s for service testing. The YB-17 incorporated a number of significant changes from the Model 299, including more powerful Wright R-1820-39 Cyclone engines replacing the original Pratt & Whitneys. Although the prototype was company owned and never received a military serial ("the B-17 designation itself did not appear officially until January 1936, nearly three months after the prototype crashed"), the term "XB-17" was retroactively applied to the airframe and has entered the lexicon to describe the first Flying Fortress.
On 1 March 1937, 12 of the 13 YB-17s were delivered to the 2nd Bombardment Group at Langley Field in Virginia, and used to help develop heavy bomber techniques and work out other bugs. One suggestion was the use of a checklist, to avoid accidents such as the Model 299's. In one of their first missions, three B-17s, following lead navigator Lt. Curtis LeMay, were sent by General Andrews to "intercept" the Italian ocean liner Rex 800 statute miles (1,300 km) off the Atlantic coast and take photographs. The successful mission was widely publicized.. The 13th YB-17 was delivered to the Material Division at Wright Field, Ohio, to be used for flight testing.
A 14th YB-17 (37-369), originally constructed for ground testing of the airframe's strength, was upgraded and fitted with exhaust-driven turbochargers. Scheduled to fly in 1937, it encountered problems with the turbochargers and its first flight was delayed until 29 April 1938. Modifications cost Boeing US$100,000 and took until spring 1939 to complete, but resulted in an increased service ceiling and maximum speed. The aircraft was delivered to the Army on 31 January 1939 and was redesignated B-17A to signify the first operational variant.
In late 1937, the Air Corps ordered ten more aircraft, designated B-17B and, soon after, another 29. Improved with larger flaps, rudder and Plexiglas nose, the B-17Bs were delivered between July 1939 and March 1940. They equipped two bombardment groups, one on each U.S. coast.
Prior to the attack on Pearl Harbor, fewer than 200 B-17s were in service with the Army, but production quickly accelerated, and the B-17 became the first truly mass-produced large aircraft. The aircraft went on to serve in every World War II combat zone, and by the time production ended in May 1945, 12,731 aircraft had been built by Boeing, Douglas and Vega (a subsidiary of Lockheed).
The B-17 began operations in World War II with the RAF in 1941, USAAF Eighth Air Force and Fifteenth Air Force units in 1942, and was primarily involved in the daylight precision strategic bombing campaign against German industrial targets. Operation Pointblank guided attacks in preparation for a ground assault.
During World War II, the B-17 equipped 32 overseas combat groups, inventory peaking in August 1944 at 4,574 USAAF aircraft worldwide, and dropped 640,036 long tons (650,195 tonnes) of bombs on European targets (compared to 452,508 tons (451,691 tonnes) dropped by the Liberator and 463,544 tons (420,520 tonnes) dropped by all other U.S. aircraft). Approximately 4,750, or one third, of B-17s built were lost in combat.
By September, after the RAF had lost eight B-17Cs in combat or to accidents, Bomber Command had abandoned daylight bombing raids due to the Fortress I's poor performance. The remaining aircraft were transferred to different commands for deployment to various duties including coastal defence. The experience had 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, which would be incorporated in later versions. Moreover, even with these improvements, it was the USAAF and not the RAF that was willing to remain faithful to using the B-17 as a "day" bomber.
Bomber Command transferred its remaining Fortress I aircraft to Coastal Command for use as very long range patrol aircraft. These were later augmented in August 1942 by 19 Fortress Mk II and 45 Fortress Mk IIA (B-17F and B-17E, respectively — the USAAF offered the B-17F before offering the B-17E, thus the apparently reversed designations). A Fortress from No. 206 Squadron RAF sank U-627 on 27 October 1942: the first of 11 U-boat kills credited to RAF Fortress bombers during the war.
The Air Corps (renamed United States Army Air Forces or USAAF in 1941), utilizing the B-17 and other bombers, bombed from high altitudes using the then-secret Norden Bombsight, which was an optical electro-mechanical gyro-stabilized computer. During daylight bombing missions and sorties, the device was able to determine, from variables input by the bombardier, the point in space at which the bomber's ordnance type should be released to hit the target. The bombardier essentially took over flight control of the aircraft during the bomb run, maintaining a level attitude during the final moments.
The USAAF began building up its air forces in Europe using B-17Es soon after entering the war. The first Eighth Air Force units arrived in High Wycombe, England on 12 May 1942, to form the 97th Bomb Group. On 17 August 1942, 18 B-17Es of the 97th, including Yankee Doodle, flown by Major Paul Tibbets and Brigadier General Ira Eaker, were escorted by RAF Spitfires on the first USAAF raid over Europe, against railroad marshalling yards at Rouen-Sotteville in France. The operation was a success, with only minor damage to two aircraft.
The two different strategies of the American and British Bomber commands were organized at the Casablanca Conference in January 1943. The resulting Operation Pointblank described a "Combined Bomber Offensive" that would weaken the Wehrmacht and establish air superiority in preparation of a ground offensive.
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.
On 17 April 1943, an attack on the Focke-Wulf plant at Bremen by 115 Fortresses met with little success. Sixteen aircraft were shot down, and 48 others were damaged. The attacks did succeed, however, in diverting about half the Luftwaffe's fighter force to anti-bomber operations.
Since the airfield bombings were not appreciably reducing German fighter strength, additional B-17 groups were formed, Eaker ordered major missions deeper into Germany against important industrial targets. The 8th Air Force then targeted the ball-bearing factories in Schweinfurt, hoping to cripple the war effort there. The first raid on 17 August 1943 did not result in critical damage to the factories, with the 230 attacking B-17s being intercepted by an estimated 300 Luftwaffe fighters. Thirty-six aircraft were shot down with the loss of 200 men, and coupled with a raid earlier in the day against Regensburg, a total of 60 B-17s were lost that day.
A second attempt on 14 October 1943 would later come to be known as "Black Thursday". Of the 291 attacking Fortresses, 59 were shot down over Germany, one ditched in the English Channel, five crashed in England, and 12 more were scrapped due to battle damage or crash-landings (more by AA guns than the Luftwaffe), a total loss of 77 B-17s. One hundred and twenty-two bombers were damaged to some degree and needed repairs before their next flight. Out of 2,900 men in the crews, about 650 men did not return, although some survived as POWs. Five were killed and 43 wounded in the damaged aircraft that made it home, and 594 were listed as Missing in Action. Only 33 bombers landed without damage.
These losses of air crews could not be sustained, and the USAAF, recognizing the vulnerability of heavy bombers against interceptors, suspended daylight bomber raids deep into Germany until the development of an escort fighter that could protect the bombers all the way from the United Kingdom to Germany and back. The Eighth Air Force alone lost 176 bombers in October 1943. The Eighth Air Force was to suffer similar casualties on 11 January 1944 on missions to Oschersleben, Halberstadt and Brunswick. Doolittle had ordered the mission to be cancelled as the weather deteriorated, but the lead units had already entered hostile air space and continued with the mission. Most of the escorts turned back or missed the rendezvous, as a result 60 B-17s were destroyed A third raid on Schweinfurt on 24 February 1944 highlighted what came to be known as "Big Week". With P-51 Mustang and P-47 Thunderbolt fighters (equipped with improved drop tanks to extend their range) escorting the American heavies all the way to and from the targets, only 11 of 231 B-17s were lost. The escort fighters reduced the loss rate to below seven percent, with only 247 B-17s lost in 3500 sorties while taking part in the Big Week raids.
By September 1944, 27 of the 40 bomb groups of the Eighth Air Force and six of the 21 groups of the Fifteenth Air Force utilized B-17s. Losses to flak continued to take a high toll of heavy bombers through 1944, but by 27 April 1945, (two days after the last heavy bombing mission in Europe) the rate of aircraft loss was so low that replacement aircraft were no longer arriving and the number of bombers per bomb group was reduced. The Combined Bomber Offensive was effectively complete.
On 7 December 1941, a group of a dozen B-17s of the 38th (four B-17C) and 88th (eight B-17E) Reconnaissance Squadrons, en route to reinforce the Philippines, were flown into Pearl Harbor from Hamilton Field, California, arriving during the Japanese attack. Leonard "Smitty" Smith Humiston, co-pilot on 1st Lt. Robert H. Richards' B-17C, 40-2049, reported that he thought the U.S. Navy was giving the flight a 21 gun salute to celebrate the arrival of the bombers, after which he realized that Pearl Harbor was under attack. The Fortress came under fire from Japanese fighter aircraft, though the crew was unharmed with the exception of one who suffered an abrasion on his hand. Enemy activity forced an abort from Hickam to Bellows Field where the aircraft overran the runway, and into a ditch where it was then strafed. Although initially deemed repairable, 40-2049 (11th BG / 38th RS) suffered more than 200 bullet holes and never flew again. Ten of the twelve Fortresses survived the attack.
By 1941, the Far East Air Force (FEAF) based at Clark Field in the Philippines had 35 B-17s, with the War Department eventually planning to raise that to 165. When the FEAF received word of the attack on Pearl Harbor, General Lewis H. Brereton sent his bombers and fighters on various patrol missions to prevent them from being caught on the ground. Brereton planned B-17 raids on Japanese air fields in Formosa, in accordance with Rainbow 5 war plan directives, but this was overruled by General Douglas MacArthur. A series of disputed discussions and decisions, followed by several confusing and false reports of air attacks, delayed the authorization of the sortie. By the time that the B-17s and escorting Curtiss P-40 fighters were about to get airborne, they were destroyed by Japanese bombers of the 11th Air Fleet. The FEAF lost fully half its aircraft during the first strike, and was all but destroyed over the next few days.
Another early World War II Pacific engagement on 10 December 1941 involved Colin Kelly who reportedly crashed his B-17 into the Japanese battleship Haruna, which was later acknowledged as a near bomb miss on the light cruiser Ashigara. Nonetheless, this deed made him a celebrated war hero. Kelly's B-17C 40-2045 (19th BG / 30th BS) crashed about six miles (10 km) from Clark Field after he held the burning Fortress steady long enough for the surviving crew to bail out. Kelly was posthumously awarded the Distinguished Service Cross. Noted Japanese ace Saburo Sakai is credited with this kill, and in the process, gained respect for the ability of the Fortress to absorb punishment.
B-17s were used in early battles of the Pacific with little success, notably the Battle of Coral Sea and Battle of Midway. While there, the Fifth Air Force B-17s were tasked with disrupting the Japanese sea lanes. Air Corps doctrine dictated bombing runs from high altitude, but it was soon discovered that only one percent of their bombs hit targets. However, B-17s were operating at heights too great for most A6M Zero fighters to reach, and the B-17's heavy gun armament was easily more than a match for lightly protected Japanese planes.
On March 2 1943, six B-17s of the 64th Squadron attacked a major Japanese troop convoy from 10,000 ft (3 km) during the early stages of the Battle of the Bismarck Sea, off New Guinea, using skip bombing to sink three merchant ships including the Kyokusei Maru. A B-17 was shot down by a New Britain-based A6M Zero, whose pilot then machine-gunned some of the B-17 crew members as they descended in parachutes and attacked others in the water after they landed. Later, 13 B-17s bombed the convoy from medium altitude, causing the ships to disperse and prolonging the journey. The convoy was subsequently all but destroyed by a combination of low level strafing runs by Royal Australian Air Force Beaufighters, and skip bombing by USAAF B-25 Mitchells at 100 ft (30 m), while B-17s claimed five hits from higher altitudes.
A peak of 168 B-17 bombers were in theater in September 1942, with all groups converting to other types by mid-1943.
Before the advent of long-range fighter escorts, B-17s had only their .50 in (12.7 mm) 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. The number of defensive guns increased from four 0.50 (12.7 mm) inch machine guns and one 0.30 inch (7.62 mm) nose machine gun in the B-17C, to 13 0.50 inch (12.7 mm) machine guns in the B-17G. But because the bombers could not maneuver when attacked by fighters, and during their final bomb run they needed to be flown straight and level, individual aircraft struggled to fend off a direct attack.
A 1943 survey by the Air Corps found that over half the bombers shot down by the Germans had left the protection of the main formation. To address this problem, the United States developed the bomb-group formation, which evolved into the staggered combat box formation where all the B-17s could safely cover any others in their formation with their machine guns, making a formation of the bombers a dangerous target to engage by enemy fighters. Luftwaffe "Jagdflieger" (fighter pilots) likened attacking a B-17 combat box formation to encountering a fliegendes Stachelschwein, or "flying porcupine". However, the use of this rigid formation meant that individual aircraft could not engage in evasive manoeuvres: they had to always fly in a straight line, which made them vulnerable to the German 88 mm anti-aircraft gun. Additionally, German fighter aircraft later used the tactic of high-speed strafing passes rather than engaging with individual aircraft to inflict maximum damage with minimum risk.
As a result, the B-17s' loss rate was up to 25% on some early missions (60 of 291 B-17s were lost in combat on the second Raid on Schweinfurt), and it was not until the advent of effective long-range fighter escorts (particularly the P-51 Mustang)— resulting in the degradation of the Luftwaffe as an effective interceptor force between February and June 1944 — that the B-17 became strategically potent.
The B-17 was noted for its ability to absorb battle damage, still reach its target and bring its crew home safely. Wally Hoffman, a B-17 pilot with the Eighth Air Force during World War II, said, "The plane can be cut and slashed almost to pieces by enemy fire and bring its crew home. Martin Caidin reported one instance in which a B-17 suffered a midair collision with a Focke-Wulf 190, losing an engine and suffering serious damage to both the starboard horizontal stabilizer and the vertical stabilizer, and being knocked out of formation by the impact. The airplane was reported as shot down by observers, but it survived and brought its crew home without injury. Its toughness more than compensated for its shorter range and lighter bomb load when compared to the Consolidated B-24 Liberator or the British Avro Lancaster heavy bombers. Stories abound of B-17s returning to base with tails having been destroyed, with only a single engine functioning or even with large portions of wings having been damaged by flak. This durability, together with the large operational numbers in the Eighth Air Force and the fame achieved by the "Memphis Belle", made the B-17 a significant bomber aircraft of the war.
The B-17 design went through eight major changes over the course of its production, culminating in the B-17G, differing from its immediate predecessor by the addition of a chin turret with two .50 inch (12.7 mm) caliber M2 Browning machine guns under the nose. This eliminated the B-17's main defensive weakness in head-on attacks.
After examining wrecked B-17s and B-24s, Luftwaffe officers discovered that at least 20 hits with 20 mm shells fired from the rear could bring them down. Pilots of average ability hit the bombers with only about two percent of the rounds they fired, so to obtain 20 hits, the average pilot had to aim one thousand 20 mm rounds at the bomber. Early versions of the Fw 190, one of the best German interceptor fighters, were equipped with two 20 mm MG FF cannons, which carried only 500 rounds, and later with the better Mauser MG 151/20 cannons, which had a longer effective range than the MG FF weapon. The fighter's firing range, 400 meters, was also shorter than the B-17's 1,000 meters, and so was vulnerable while closing in through that distance. The German fighters found that when attacking from the front, where fewer defensive guns were pointed, it only took four or five hits to bring a bomber down. To address the Fw 190's shortcomings, the number of cannons fitted was doubled to four with a corresponding increase in the amount of ammunition carried, and in 1944, a further upgrade to 30 mm MK 108 cannons was made, which could bring a bomber down in just a few hits.
The adoption by the Luftwaffe in mid-August 1943, as a "stand-off" style of offense, of the Werfer-Granate 21 (Wfr.Gr. 21) Dodel rocket mortar, with one strut-mounted tubular launcher fixed under each wing panel on the Luftwaffe's single engined fighters, and two under each wing panel on a few Bf 110 daylight Zerstörer aircraft, had the promise of being a major weapon, but due to the ballistic drop of the fired rocket, even with the usual strut mounting of the launcher fixing it in about a 15° upward orientation, and the low numbers of fighters fitted with the Dodel weapons, the Wfr.Gr. 21 never had a major effect on the combat box fomations of Fortresses. Also, the attempts of the Luftwaffe to fit heavy-calibre Bordkanone-series 37, 50 and even 75 mm cannon on twin engined aircraft such as the special Ju 88P fighters, and even on one model of the Me 410 Hornisse, as anti-bomber weapons did not have much effect on the American strategic bomber offensive. The Me 262 had moderate success against the B-17 late in the war. Equipped with the R4M rocket, it could fire from outside the range of the bombers' .50 caliber defensive guns and bring an aircraft down with one hit.
During World War II, after crash-landing or being forced down, approximately 40 B-17s were captured and refurbished by the Luftwaffe with about a dozen put back into the air. Given German markings and codenamed "Dornier Do 200", the captured B-17s were used for clandestine spy and reconnaissance missions by the Luftwaffe — most often used by the Luftwaffe unit known as Kampfgeschwader 200. One of the B-17s of KG200, bearing Luftwaffe markings A3+FB, was interned by Spain when it landed at Valencia airport, 27 June 1944, and remained there for the rest of the war. Some B-17s kept their Allied markings and were used in attempts to infiltrate B-17 formations and report on their position and altitude. The practice was initially successful, but the Army Air Force 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. Still other B-17s were used to determine the airplane's vulnerabilities and to train German interceptor pilots in tactics. Few surviving aircraft were found by the Allies following the war.
Several B-17s along with other World War II bombers were converted into airliners. Other B-17s saw extended and valiant service as converted aerial tankers used for fighting forest fires in the western United States.
|Model 299||1||28 July 1935|
|YB-17||13||2 December 1936|
|YB-17A||1||29 April 1938.|
|B-17B||39||27 June 1939|
|B-17C||38||21 July 1940|
|B-17D||42||3 February 1941|
|B-17E||512||5 September 1941|
|B-17F||3,405||30 May 1942|
The B-17 went through several alterations in each of its design stages and variants. Of the 13 YB-17s ordered for service testing, 12 were used by the 2nd Bomb Group of Langley Field, Virginia to develop heavy bombing techniques, and the 13th was used for flight testing at the Material Division at Wright Field, Ohio. Experiments on this aircraft led to the use of a turbo-supercharger, which would become standard on the B-17 line. A 14th plane, the Y1B-17A, originally destined for ground testing only, was upgraded with the turbocharger. When this aircraft had finished testing, it was re-designated the B-17A, and in April 1938 was the first aircraft to enter service under the B-17 designation.
As the production line developed, Boeing engineers continued to improve upon the basic design. To enhance performance at slower speeds, the B-17B was altered to include larger rudder and flaps. The B-17C changed from gun blisters to flush, oval-shaped windows. Most significantly, with the B-17E version, the fuselage was extended by , a much larger vertical fin and rudder were incorporated into the original design, a gunner's position in the tail and an improved nose were added. The engines were upgraded to more powerful versions several times, and similarly, the gun stations were altered on numerous occasions to enhance their effectiveness.
By the time the definitive B-17G appeared, the number of guns had been increased from seven to 13, the designs of the gun stations were finalized, and other adjustments were complete. The B-17G was the final version of the B-17, incorporating all changes made to its predecessor, the B-17F, and in total 8,680 were built, the last one on 9 April 1945. Many B-17Gs were converted for other missions such as cargo hauling, engine testing and reconnaissance. Initially designated SB-17G, a number of B-17Gs were also converted for search-and-rescue duties, later to be redesignated B-17H.
Two versions of the B-17 were flown under different designations. These were the XB-38 and the YB-40. The XB-38 was an engine test-bed for Allison V-1710 liquid-cooled engines, should the Wright engines normally used on the B-17 become unavailable. The YB-40 was a heavily armed modification of the standard B-17 used before the P-51 Mustang, an effective long-range fighter, became available to act as escort. Additional armament included a power turret in the radio room, a chin turret (which went on to become standard with the B-17G) and twin .50 caliber (12.7 mm) guns in the waist positions. The ammunition load was over 11,000 rounds, making the YB-40 well over 10,000 lb (4,500 kg) heavier than a fully loaded B-17F. Unfortunately, the YB-40s with their numerous heavy modifications had trouble keeping up with empty bombers, and so, together with the advent of the P-51 Mustang, the project was abandoned and finally phased out in July 1943.
Late in World War II, at least 25 B-17s were fitted with radio controls, loaded with 20,000 pounds (9,000 kg) of high-explosives, dubbed "BQ-7 Aphrodite missiles". "Attacks on the V-site bunkers were also initiated by the Americans using radio controlled bombers packed with . of Torpex and TNT. Called Aphrodite drones, operation 'CASTOR' was begun on June 23 1944, using the 388th Bombardment Group at Knettishall. An airfield in a sparsely populated area of Norfolk was chosen at RAF Fersfield. The drone was usually a B-17 Fortress with a B-34 Ventura being used to control the aircraft and crash it onto its target." "The first four drones were sent to Mimoyecques, Siracourt, Watten and Wizernes on August 4, causing little damage. On the 6th two more B-17s were crashed on the Watten site with little success. The project came to a sudden end with the unexplained mid-air explosion over the Blyth estuary of a Liberator, part of the United States Navy's contribution as project Anvil, en route for Heligoland piloted by Lieutenant" Joseph P. Kennedy Jr., future U.S. president John F. Kennedy's eldest brother. Blast damage was caused over a radius of five miles (8 km). British authorities were anxious that no similar accidents should again occur. Ramsey, Winston G. The V-Weapons. London, United Kingdom: After The Battle, Number 6, 1974, page 21. Because few (if any) BQ-7s hit their target, the Aphrodite project was scrapped in early 1945. During and after World War II, a number of weapons were tested and used operationally on B-17s. Some of these weapons included "razons" (radio-guided) glide bombs, and Ford-Republic JB-2 Loons, also nicknamed Thunderbugs — American reverse-engineered models of the German V-1 Buzz Bomb. A much-used travelling airborne shot of a V-1/JB-2 launch in World War II documentaries was filmed from a USAF A-26 of the Air Proving Grounds, Eglin Air Force Base, launched from Santa Rosa Island, Florida. In the late 1950s, the last B-17s in United States Air Force service were QB-17 drones and DB-17P drone controllers, plus a few polished VB-17 squadron "hacks" (a 1953 request by the Wright Air Development Center to redesignate the QB-17s to Q-7 was turned down by Air Research & Development Command). The last operational mission flown by a USAF Fortress was conducted on 6 August 1959, when DB-17P 44-83684 directed QB-17G 44-83717 out of Holloman Air Force Base as a target for a Falcon air-to-air missile fired from an F-101 Voodoo fighter. A retirement ceremony was held several days later at Holloman, after which 44-83684 was retired to the Military Aircraft Storage and Disposition Center (MASDC) at Davis-Monthan Air Force Base.
The B-17 was a versatile aircraft, serving in dozens of USAAF units in theaters of combat throughout World War II, and in non-bomber roles for the RAF. Its main use was in Europe, where its shorter range and smaller bombload relative to other aircraft available did not hamper it as much as in the Pacific Theater. Peak USAAF inventory (in August 1944) was 4,574 worldwide.:::::::::::::::::::::
The B-17 Flying Fortress has become, for many reasons, an icon of American power and a symbol of its Air Force. It achieved a lasting fame in the general public, which has eluded most other bomber aircraft.
During the 1930s, the USAAC, under Gen. Frank Maxwell Andrews and the Air Corps Tactical School, touted the bomber as a strategic weapon. Gen Henry H. Arnold, Chief of the Air Corps, recommended the development of bigger aircraft with better performance and the Tactical School agreed completely. The B-17 was exactly what the Air Corps was looking for; it was a high-flying, long-ranging potent bomber capable of defending itself.
When the Model 299 was rolled out on 28 July 1935, bristling with multiple machine gun installations, Richard Williams, a reporter for the Seattle Times coined the name "Flying Fortress" with his comment "Why, it's a flying fortress!". Boeing was quick to see the value of the name and had it trademarked for use.
After the initial B-17s were delivered to the Air Corps 2nd Bombardment Group, they began sending them on promotional flights emphasizing its great range and navigational precision. In early 1938, Group commander Colonel Robert C. Olds flew a Y1B-17 from the east to west coast, setting a transcontinental record of 12 hours 50 minutes. He also broke the west-to-east coast record on the return trip, averaging in ten hours 46 minutes. Six bombers of the 2nd Bombardment group took off from Langley AFB on 15 February 1938 as part of a good will flight to Buenos Aires, Argentina. Covering they returned on 27 February. In a well publicized mission, three B-17s, "intercepted" and took photographs of the Italian ocean liner Rex off the Atlantic coast.
The Flying Fortress found a place in the public psyche as well. In 1943, Consolidated Aircraft commissioned a poll to see “to what degree the public is familiar with the names of the Liberator and the Flying Fortress.” Of 2,500 men in cities where Consolidated ads had been run in newspapers, only 73 percent had heard of the Liberator, while 90 percent knew of the B-17.
Hollywood featured the airplane in its movies, such as Twelve O'Clock High, with Gregory Peck. This film was made with the full cooperation of the United States Air Force and made use of actual combat footage. In 1964 the movie was made into a television show of the same name, and ran for three years. The B-17 also appeared in the 1938 movie Test Pilot with Clark Gable and Spencer Tracy.
During the war, the largest offensive bombing force, the Eighth Air Force, was run by officers who openly preferred the B-17. Lt. Gen. Jimmy Doolittle wrote about his preference for equipping the Eighth with B-17s. Citing the logistical advantage in keeping fielded forces down to a minimum number of aircraft types with their unique servicing and spares, he wanted B-17 bombers and P-51 fighters for the Eighth. His views were supported by Eighth Air Force statisticians, whose studies purportedly showed that Fortresses had utility and survivability much greater than that of the B-24.
Loved by its crews for bringing them home despite extensive battle damage, its durability, especially in belly-landings and ditchings, quickly took on mythical proportions. Stories and photos of B-17s surviving battle damage widely circulated, boosting its iconic status. Despite an inferior performance and bombload compared to the more numerous B-24 Liberator, a survey of Eighth Air Force crews showed a much higher rate of satisfaction in the B-17.
The most famous B-17, the Memphis Belle, toured the U.S. with its crew to reinforce national morale (and to sell War Bonds), and starred in a USAAF documentary, Memphis Belle: A Story of a Flying Fortress.
After the war ended, most B-17s were scrapped, but the U.S. Air Force did keep some B-17s for VIP transports and drone directors. The United States Navy and U.S. Coast Guard obtained thirty B-17s beginning in 1945 for over-water patrols as PB-1Gs, an air rescue aircraft similar to USAF B-17Hs, and PB-1Ws, a patrol aircraft with early warning radar installations aboard. The war ended before any PB-1Ws were operational and defensive armament was subsequently deleted. The Coast Guard retired the last PB-1G, BuNo 77254, in October 1959, making it the last U.S. military Flying Fortress in operation.
Throughout the 1960s and 1970s, the surviving Fortresses had to earn their keep, as operation of a four-engine aircraft was costly, and the Warbirds preservation movement had not yet begun. The preservation of the remaining Fortresses gained steam when firebomber B-17s began to come on the market in the 1970s.
The Memphis Belle is possibly the most culturally ubiquitous of the Flying Fortresses. Most recently known from a movie produced in 1990, the famed Memphis Belle and its crew incorrectly entered the annals of American pop-culture as the first in the Eighth Air Force to complete a tour of 25 combat missions.
In the early 1970s, another mayor had donated the historic aircraft back to the U.S. Air Force, but they allowed it to remain in Memphis contingent on it being maintained. Efforts by the locally-organized Memphis Belle Memorial Association, Inc. (MBMA) saw the aircraft moved to Mud Island in the Mississippi River in 1987 for display in a new pavilion with roof cover. It was still open to the elements, however, and prone to weathering. Dissatisfaction with the site led to efforts to create a new museum facility in nearby Shelby County, Tennessee. In the summer of 2003 the Belle was disassembled and moved to a restoration facility in Millington, Tennessee for work. In September 2004, however, the National Museum of the United States Air Force, apparently tiring of the ups and downs of the city's attempts to preserve the aircraft, indicated that they wanted it back for restoration and eventual display at the USAF museum at Wright-Patterson AFB near Dayton, Ohio. The aircraft arrived in pieces at the Museum's restoration facility in 2005, and was immediately made a top priority project. A thorough examination of "Memphis Belle" found the condition of the aircraft to be far worse than had been previously indicated, with extensive corrosion throughout the airframe, and paint that had been crudely applied in an effort to insulate the metal. The aircraft was completely stripped of all paint save its "nose art" and is currently undergoing thorough restoration efforts by NMUSAF Staff at Wright-Patterson AFB. The restoration is expected to be completed on or around 2014.
The Swoose, B-17D-BO, 40-3097, the only surviving intact example of the shark fin B-17s of the A, B, C and D series, flew combat missions in the Pacific Theater before being converted to an unarmed transport/flying command-post used in Australia by Lt. Gen. George Brett, commander of Allied air forces in the South West Pacific Area. It returned to the United States with Brett in 1943, and is the oldest intact surviving B-17 in the world.
Col. Frank Kurtz, commanding officer of the 463rd Bombardment Group at the Celone Airbase near Foggia, Italy, and the father of actress Swoosie Kurtz (b. 1944), carried the Swoose name forward from the original Swoose (which he flew in the Pacific prior to being named CO of the 463rd), naming the B-17G he flew with the 463rd "Swoose II". The 463rd BG was thereafter known as the "The Swoose Group". The name "Swoosie" was a derivative of Kurtz's Pacific aircraft, so-named by 19th Bomb Group pilot Captain Weldon Smith, after the tail of 40-3091 was grafted onto 40-3097, resulting in an aircraft that was "half-swan, half-goose", from bandleader Kay Kyser's song, Alexander the Swoose. The aircraft had originally been named "Ole Betsy".
In July 2008 "The Swoose" was transferred from the National Air and Space Museum's storage facility in Maryland to the National Museum of the United States Air Force (NMUSAF) in Dayton, Ohio. The Museum's restoration staff plan to restore the aircraft to its pre-WWII condition, including markings of the 11th BG. Once the aircraft is restored it will be placed on display in the Museum's Early Years Gallery.
The decision by the National Museum of the United States Air Force to trade one of its most popular exhibits, "B-17G "Shoo Shoo Baby", to the NASM in exchange for the deteriorated hulk of "The Swoose" was met with some skepticism by staff and patrons of the Museum. Untimately the decision was made based on the following points: first, since being donated to the NASM the condition of "The Swoose", the world's last surviving "shark-tailed" B-17D, has been allowed to deteriorate significantly, and there were no plans to ever restore or display the aircraft. Secondly, once restoration of "The Swoose" and "Memphis Belle" are complete, the NMUSAF will possess, display and maintain the world's two most historically significant B-17s. This in no way prevents the museum from obtaining another "G" model if funds and opportunity present itself.
Shoo Shoo Baby (a third Shoo was added to the name just before its loss), B-17G-35-BO, 42-32076, 401st BS, 91st Bomb Group, marked LL-E, flew 24 combat missions from England with the 91st Bomb Group from March 1944 until being forced to crash land at Malmö Airport, Sweden. Being neutral, Sweden interned the crew, and about the same time a deal was made between the Swedish and U.S. governments to allow around 300 American crewmen to return in exchange for nine B-17Fs and B-17Gs that had landed intact in Sweden. Seven of these were converted by Saab Aircraft into airliners that could carry 14 passengers. Eventually sold first to Denmark and then to France, it was recovered in 1972, dismantled, and flown in a C-5 Galaxy to Dover Air Force Base, Delaware, for restoration. It flew to the National Museum of the United States Air Force, and was turned over on 13 October 1988, where it is now on display. Due to the amount of sheet metal work required to restore its wartime configuration, it is finished in olive drab and grey, instead of bare metal as it was during its USAAF service.
Shoo Shoo Baby was officially traded to the National Air and Space Museum in 2008 in exchange for the unrestored B-17D "The Swoose". "Shoo Shoo Baby" will remain on exhibit at the National Museum of the United States Air Force until restoration of B-17F "Memphis Belle" is completed, which is expected on or around 2014. At that time "Shoo Shoo Baby" will be transferred to the Udvar B. Hazy Center at Dullas Airport.
The Nine-O-Nine, a B-17G-30-BO, 42-31909, of the 91st Bomb Group, 323rd Bomb Squadron, completed 140 missions without an abort or loss of a crewman, an 8th Air Force record. Assigned to combat on 25 February 1944 she made 18 trips to Berlin, dropped 562,000 pounds of bombs, and flew 1,129 hours. She had 21 engine changes, four wing panel changes, 15 main fuel tank changes, and 18 "Tokyo" tank changes (long-range fuel tanks). M/Sgt. Rollin L. Davis, a maintenance line chief in charge of this plane, received the Bronze Star for his part in this. She wound up at the RFC facility at Kingman, Arizona on 7 December 1945, and was scrapped. The Collings Foundation,Stow, Massachusetts, have B-17G-85-DL, 44-83575, civil register N93012, which currently appears at airshows marked as the historic Nine-O-Nine.
Sally B is the only B-17 flying in the United Kingdom and thus serves as a memorial of the U.S. 8th Air Force which fought from England in World War II and the American airmen who fought and died during that conflict.
Built as a Boeing B-17G-105-VE c/n 8693, the future Sally B was one of the last to be constructed by the Lockheed-Vega plant at Burbank, California. Accepted by the United States Army Air Force (USAAF) as 44-85784 on 19 June 1945 it was too late to see war service, and was flown to Nashville for modifications. Converted for training purposes and re-designated TB-17G it was based at Wright Field (now Wright-Patterson AFB), Ohio from November that year.
Continuing in the care of 2750th Air Base Group (ABG), 44-85784 was selected for use as a research vehicle and in 1949 allocated EB-17G status. As such the B-17 was used in a variety of research roles, one of the most bizarre being the addition of a man-carrying pod on the starboard wingtip. Also fitted at the time was an infra-red tracking device in place of the Perspex nose. These trials continued for some years in a variety of guises and it was not until 1954 that ‘784 was returned to standard configuration, less armaments, at Hill AFB in Utah. No details have emerged of the trials which this aircraft was involved in.
In 1990, Sally B was redressed to depict Memphis Belle in the feature film of the same name, directed by Michael Caton-Jones. After the film shooting was over, she reverted back to show her "Sally B" titles on the starboard side, but has since retained the "Memphis Belle" logo on the port side.
Sally B continues to be flown at displays as a memorial to the 79,000 U.S. airmen who died fighting in the skies over Europe between 1942 and 1945.
The Navy used PB-1Ws as the original Airborne Warning and Command System or AWACS aircraft, as well as for electronic countermeasures, anti-submarine warfare and hurricane hunters. The Navy sealed up the bomb bay doors, installed 300 gallon wing-mounted drop tanks and the AN/APS-20 Seasearch Radio Detection and Ranging (RADAR) equipment in a bulbous housing below the former bomb bay. Radio direction finder (RDF), instrument landing system (ILS), and long range navigation (LORAN) were also installed. She was not painted, but waxed to prevent corrosion, and kept her original Browning M2 machine guns.
Texas Raiders tours the North American air show circuit and both commemorates and wears the markings of the U.S. Army Air Corps 8th Air Force, 1st Air Division, 381st Bombardment Group (Heavy), 533rd Bombardment Squadron's aircraft "hull number" X. The aircraft is currently on its third and most thorough restoration at the Commemorative Air Force's Gulf Coast Wing, at the William P. Hobby airport, in Houston, Texas, with the intention of returning it to airworthy status.