Boeing B-17 Flying Fortress

The Boeing B-17 Flying Fortress (in Spanish: «Fortaleza Volante») is a famous four-engined heavy bomber of World War II, manufactured since 1935 and commissioned in 1937 with the Corps United States Army Air Force (USAAC) and the British Royal Air Force (RAF).

It flew thousands of missions with the Allies during the war, mostly in Europe, although it also took part in the Pacific campaign, proving to be one of the most reliable bombers in the war, along with the Consolidated B-24 Liberator. The latest versions of this bomber were armed with 13 12.7mm machine guns and could carry nearly 8,000kg of bombs (depending on model).

Development

Air Force B-17 bombing a Focke Wulf plant in Marienburg, Germany, today Malbork, Poland, in 1943.

A total of 12,677 aircraft were built for the Allies. Most were built at Boeing's plants in Seattle, Washington, and Wichita, Kansas, but this was not the only manufacturer: they were also produced by the Douglas Aircraft Company at its Long Beach, California plant, and the Vega subsidiary of the Lockheed Corporation. About a third of the total, some 4,750, were lost in combat missions. During these missions they dropped 640,036 tons of bombs on European targets.

The B-17 was based on Boeing's B-299 model, which in turn borrowed from an earlier prototype, the 294, the idea of using four engines, and a commercial Boeing model, the 247, the all-metal construction.

The first models

The first prototype flew on July 28, 1935. The following models were produced:

• The prototype B-299.
• The initial version of evidence Y1B-17Of which 13 units were built. Serial numbers 36-149 a 36-161.
• A Y1B-17 was converted to prototype for destruction tests, the 36-151to which the serial number was reassigned 37-369and was appointed Y1B-17A (laughs) B-17A). This aircraft tested the Wright R-1820-51 (G5) radial Cyclone with Moss-General Electric compressors, which elevated the power to 800 hp to 25 000 feet (7625 m) of altitude, increased the autonomy and allowed a higher maximum load (20 725 kg). All the following models would be equipped with compressors.
• The first production series, designated B-17Bof which 39 units were built. Serial numbers 38-211/223, 38-258/270, 38-583/584, 38-610 and 39-1/10.
• The second production series, with modifications to the previous one, were 38 units (serial numbers 40-2042 a 40-2079) ordered in 1939 and designated B-17C. Of this series, 20 units were withdrawn to be delivered to the RAF under the law of Loan and Burning (Lend-Lease). All units that remained in the U.S. armed forces returned to the factory in February, 1941, to be converted to the new model B-17D.
• In April 1940, 40 were commissioned B-17C more. This new series presented differences with the previous one, so they were appointed B-17D (series numbers 40-3059/3100). The first aircraft in this series flew on 3 February 1941.

Mass production

A B-17G in operations.

Lockheed Vega B-17F-45. Note the lack of the turret under the bow regarding the B-17G of the higher photograph.

The famous "Memphis Belle", a Boeing B-17F Flying Fortressthe first to carry out 25 bombing missions and return safely.

• The series B-17E it was the first to happen massively. 512 units were manufactured, serial numbers 41-2393/2669 and 41-9011/9245which incorporated the novelty of two turrets with 12.7 mm Browning M2 double machine guns, one in dorsal position and another in ventral position. The first 113 units carried in the ventral position a remote control turret, but as this one revealed to be ineffective, it was replaced by a Sperry turret in the form of a bubble, in which the shooter operated manually with cranks and pedals; it was required to be of very small size to locate there, in fetal position.

The entire rear part of the fuselage was redesigned to solve a "blind zone" problem, incorporating another turret with two machine guns in the tail, which extended the fuselage by almost two meters. The fuel and bomb load capacity was increased, making the model somewhat slower and heavier than its predecessor the B-17D, but much better defended. The first unit flew on September 5, 1941, and the last left the Boeing plant on May 28, 1942. Due to increased defense positions, the B-17E crew was ten. men: pilot, co-pilot, navigator, bombardier, flight mechanic, radio operator, tail gunner, ventral gunner and two side gunners. The frontal machine gun was normally operated by the navigating officer or bombardier when not engaged in their specific duties, and the dorsal turret was usually operated by the flight engineer.

• The operational experiences of the B-17E in the Pacific led to a number of improvements resulting in the model B-17F. Although the external appearance of this model is equal to that of B-17Eexcept because the transparent prow of the new model is composed of one piece of plastic, more than 400 internal modifications were made. A new turret was installed, external assemblies for pumps, new propellers, filters for carburator air intakes, an improved oxygen system, a dual brake system, more photographic equipment, an electronic link for the autopilot and new spherical assemblies for machine guns in the morre. The engines were the new Wright R-1820-97 Cyclone, able to offer power of 1380 hp for short periods. A more robust landing gear was also installed, which raised the maximum load to 29 056 kg and then to 32 688 kg.

• The first B-17F (41-24340) flew on May 30, 1942. The constant introduction of small changes in the production line B-17F forced to use a block designation scheme to facilitate maintenance. At the same time, the incorporation of other manufacturers into production required an additional distinction. The first 50 were B-17F-1-BO ("1"for the production lot, "BOY"by Boeing." From the fourth lot, the amount of each was irregular; the last block produced by Boeing was the 130-BO.

• They were built in total 3405 B-17F. Of them, Boeing produced 2300, Douglas made 605 on his Long Beach plant, California (lotes B-17F-1-DL a -85-DL), and the Vega de Lockheed division produced 500 in Burbank, California. Them B-17F built by the three companies had no external differences (they were only recognizable by their serial numbers) and presented slight variations in the internal details, particularly in the armament. Many other modifications of the armament were made directly on the ground: the famous “Memphis Belle» had 4 caliber.50 machine guns mounted on the bow.

• To units B-17F produced were assigned the following serial numbers: 41-24340/24639 (Boeing, lots 1-BO, 10-BO, 15-BO, 20-BO, 25-BO and 27-BO); 42-2964/3562 (Douglas-Long Beach, lots 5-DL a 75-DL numbered from five to five; 42-5050/5484 (Boeing, lots 30-BO a 50-BO numbered from five to five; 42-5705/6204 (Lockheed/Vega, lots 1-VE and 5-VE a 50-VE of five in five; 42-29467/31031 (Boeing, lots 55-BO a 130-BO, numbered of five in five), and 42-37714/37720 (Douglas-Long Beach, lots 80-DL and 85-DL).

• Towards the end of production B-17F, it was decided to add a Bendix turret with two machine guns below the bow to increase defensive capacity. Changes programmed for lot 135-BO of B-17F were so many that a change of denomination was justified, B-17G. The machine guns on the sides of the bull, introduced in the last series of B-17FThey stayed, but in a new staggered arrangement. From the subseries 80-BO, 45-DL and 35-VE the assembly called "Cheyenne"for the tail machine guns, with a look for reflector, which shortened the total length by 12.7 cm. The model B-17G it was the one that came to a greater extent. When production finally ended in 1945, 8680 had been manufactured B-17G: 4035 built by Boeing, 2395 by Douglas and 2250 by Lockheed Vega.

• Them B-17G carried the serial numbers 42-31032/32116 (Boeing) 42-37716 (Douglas Long Beach) 42-37721/38213 (Douglas Long Beach) 42-39758/40057 (Lockheed Vega), 42-97058/97407 (Boeing) 42-94436/98035 (Lockheed Vega), 42-102379/102978 (Boeing) 42-106984/107233 (Douglas Long Beach) 43-37509/39508 (Boeing) 44-6001/7000 (Douglas Long Beach) 44-8001/9000 (Lockheed Vega), 44-83236/833885 (Douglas Long Beach) and 44-85492/85591 (Lockheed Vega).

Experimental and modified aircraft

• The B-17E 41-2401 was used by Lockheed/Vega as a basis for the prototype XB-38which was basically a B-17E with different motorization. Instead of the Wright radial engines, 4 12-cylinder V engines were used for water-cooled Allison V-1710-89 1425 hp. New engines increased speed and scope. But, on the one hand, the Allison engines were highly requested for the P-38 hunting planes. Lightning and P-40 Warhawk; on the other hand, the prototype that first flew on 19 May 1943 was destroyed by a fire in the engines on 16 June of the same year, and it was decided not to continue development.

• One of the most critical problems of the bombing formations was the lack of defensive coverage in far-reaching missions, since their own hunts did not have sufficient autonomy. The YB-40 It was an attempt to convert planes B-17F heavily armed escorts for day bombing missions. The prototype XB-40 was produced by VegaA Lockheed division.

They took a B-17F (serial number 41-24341) and added a dorsal turret in the radio bay position, with two caliber machine guns. 50, another turret under the nose with the same equipment, and double machine guns in each of the positions in the center of the fuselage, instead of the single ones used by the B-17F. The other turrets were retained, giving an impressive defensive armament total of 14 machine guns. More protective armor was also added, and the bomb racks were replaced with ammunition storage. In normal configuration it carried 11,135 cartridges, and if fuel was reduced it could reach 17,265 cartridges. Twenty Vega-built B-17F were refitted to YB-40 by Douglas in Tulsa, Oklahoma, and another 4 were used for training under the designation TB-40 . Different configurations were tested, and one machine had 30 machine guns.

However, it was soon discovered that the additional weight prevented the YB-40 from keeping in formation with the B-17 bombers, especially when returning from landing missions. bombing. The project was a failure, and all surviving YB-40s were converted back to B-17Fs; but the idea of a turret under the nose would have to be used in the B-17G.

• In 1944 he thought of launching B-17 unmanned and remotely controlled, full of explosives, against military targets that resisted conventional bombing. This operation was called Operation Aphrodite, and for it approximately 25 B-17 (most of the "F" series) that were modified, adapted to load 9 tons of explosives, and reprinted BQ-7.

• A certain number of B-17 was converted into transport for various purposes, under the denominations C-108 and CB-17. Among them, the B-17E series 41-2593 redesigned XC-108, was refurbished as transport to General Douglas MacArthur; the YC-108One. B-17F-40-VE serial number 42-6036, conditioned as the previous, the XC-108AOne. B-17E serial number 41-2595refurbished as transport of general purposes; and XC-108B, the B-17F serial number 42-30190converted into fuel transport as a prototype to test the feasibility of transport between Burma and China above the Himalayas.

• The designation F-9 was assigned to B-17 converted for photographic recognition. The entire bombing team was removed and replaced by cameras. The series F-9 was composed of 16 B-17F. An unknown number B-17F had the designation F-9Awith a configuration of cameras that differed from that of F-9. The designation F-9B was awarded to 25 reconnaissance aircraft from B-17F or F-9A readapted. Finally, the designation F-9C corresponded to 10 B-17G equipped in a similar way to the previous ones.

• During the last year of the war, and also shortly after it, 48 B-17 of the USAAF were transferred to the American Navy (US Navy) that called them PB-1 Naval Fortress. Twenty-four B-17G were equipped with ASP-20 search radars for anti-submarine fight, designated PB-1W and painted with the characteristic dark blue color of naval aviation. These PB-1W They evolved to observation and early warning aircraft, and remained in service until 1955, gradually being replaced by the Lockheed WV-3. Other number B-17 was transferred to the Coast Guard (US Coast Guard), where they operated in exploration, search and rescue missions and aerophotography under the name PB-1G, being employed for a long time: the last aircraft, manufactured by Lockheed-Vega in 1944, was withdrawn from service in October 1959. In total, 51 B-17 manufactured by Lockheed-Vega and Douglas Long Beach provided active service as aircraft units.

Operational history

RAF

The Royal Air Force (RAF) operated some B-17s. As a bomber it was not very successful there, and most were assigned to coastal surveillance and anti-submarine missions.

• From the series B-17C 20 units were assigned to the RAF. This one called them Fortress I and assigned them the serial numbers AN518 a AN537. They were identical to the B-17Cexcept that the 12.7 mm machine guns were Browning, and they were supplied with self-sealing fuel tanks.
• In the middle of 1942, 45 B-17E were transferred to the RAF, which called them Fortress IIA and assigned them the serial numbers FK184/213, FL449/460and FL462/464. Experimentally, one of the units replaced the transparent bow with a Bristol B.16 turret equipped with a 40 mm Vickers S cannon, for anti-submarine struggle.
• 19 B-17F were transferred to the RAF, which called them Fortress II and assigned them the serial numbers FA695 a FA713. Particularly prominent for coastal defence, they fought in squadrons 59, 206, 220, 251, 519 and 521 of the Coastal Command and in squadrons 214 and 223 of bombing.
• 85 B-17G were transferred to the RAF, which called them Fortress III. Thirty of them had been built by Boeing and the RAF assigned them the serials HB761 a 790and the remaining ones by Lockheed/Vega. Six of these were returned to the USAAF before entering service with the British. Three of the B-17G They served in the Castero Command of the Azores, equipped with radar at the place of the front turret.

Operators

B-17 military operators.

Civilian operators of the B-17.

Survivors

B-17G-105-DA Sentimental Journey 44-83514 preserved.

As of April 2005, 44 B-17 still survived, most of them B-17G, three B-17F, one B-17D and one B-17E. Of these, eleven were still operable, and flew occasionally; two additional operables were undergoing long-term maintenance; twenty-one were on static display and accessible to the public in Brazil, France, the United Kingdom, and the United States; four were under restoration, and the remaining six were stored.

One was lost in the 2022 Wings Over Dallas crash when it collided in mid-air with a Bell P-63 Kingcobra.

Notable specimens

For reasons of war propaganda, but also because of the audacity and courage of their crews, and sometimes just because of the humor with which their crews christened them, many B-17s entered the legend. Among them:

• "Memphis Belle"The Beauty of Memphis), the first to successfully complete 25 bombing missions, and motive for 2 films.
• "Swoose" swan, swan and Goose, goose), the only American plane that fought on the first day of the war and remained active until the end.
• "My Lovin' Dove", Boeing B-17F serial number 41-24351. It fell to the sea near the island of Nauri, South-West Pacific, on February 9, 1942. The crew was rescued after 66 days at sea.
• "Berlin Sleeper", Boeing B-17F 41-24370The first B-17 to complete 100 missions. He participated in the first night bombing mission on Ruan, France.
• "Knock-out Dropper", Boeing B-17F 41-24605 Bomber Squadron 359, Bomber Group 303, was the first B-17 to complete 50 missions on 16 November 1943, and the first with 75 missions on 27 March 1944. Dismantled in Stillwater, Oklahoma, July 1945.
• Lakanuki, Douglas Long Beach B-17F Squadron 545, Bombing Group 384. Demolished July 4, 1943 on Le Mans, France. The plane fell in the village of Poille sur Vegre. Nine crew members died, but the tenth managed to escape with the help of the French Resistance.
• Dearly Beloved, Boeing B-17F 42-29666 Squadron 423, Bombing Group 306. He fell to the North Sea on May 21, 1943, returning from an attack on Wilhelmshaven with the record of 11 enemy planes shot down. The crew was rescued by a British sweeper.
• "Fancy Nancy IV", Boeing B-17G 42-31662 Squadron 612, Pumping Group 401. Stored in Burtonwood, England, on 31 May 1945 after having carried out 134 missions.
• "Nine-O-Nine", Boeing B-17G 42-31909Squadron 323, Bombing Group 91, carried out 140 combat missions between March 1944 and March 1945 without a single crew being killed or injured. A similar plane repainted with the colors of the Nine-O-Nine crashed in October 2019 causing 7 dead.
• "Hitler's Milkman", Boeing B-17G 42-97190 Squadron 748, Bombardeo Group 457, reached by air fire during a mission to Nimega, Netherlands, on 17 September 1944. He landed in Belgium, was repaired and returned to active service. He returned to the United States on 4 June 1945.
• "Milk Wagon", Boeing B-17G 43-37756 Squadron 708, Bombing Group 447, performed 129 missions without aborting any.
• "Old 666," B-17E 41-2666 with increased defensive weaponry of the 43rd Bomber Group was faced only against 17 Japanese fighters in a reconnaissance mission on Rabaul on June 1943.
• "Ye old pub," Boeing B-17 of the USAAF that while attempting to return to its base in England, helpless and severely damaged, and flying over enemy territory and with most of its wounded or dead crew, was intercepted by a Messerschmitt Bf 109 of the Luftwaffe, whose pious and honorable pilot decided to escort him to England and let them go.
• "Shoo Shoo Baby", Boeing B-17 42-32076 Squadron 91 of RAF bombers. His first pilot was the second lieutenant (alferez or subtenant in other armies) Paul C. McDuffee. This bomber still exists and is the one that has stayed in the air longer.
• "Miss Every Morning Fix'n or "Miss E.M.F." B-17C-BO 40-2072. He crashed into what is now the site of Thomas Borthwick's Slaughterhouse, perishing 10 of the 11 crew members aboard; he survived only Foye Kenneth Roberts.
• Ol ́Gappy B-17G S/N 42-40003 524BS/379BG, Heavy with the largest number of bombing missions at the 8th AAF, 157 missions at the end of the war.

Specification Comparison Chart

Specifications (B-17G)

Reference data: The Encyclopedia of World Aircraft

Draw 3 views of Boeing B-17G.

General Features

• Triple: 10 (pilot, co-pilot, navigator, pump/prow gun, flight engineer/dorsal turret gunner, radio operator, 2 side window gunners, ventral turret gun, tail gun)
• Length: 22.7 m (74.3 ft)
• Scope: 31.6 m (103.7 ft)
• Height: 5.8 m (19.1 ft)
• Elong surface: 131.9 m2 (1420 ft2)
• Alar Profile: NACA 0018/NACA 0010
• Empty weight: 16 391 kg (36 125.8 lb)
• Weight loaded: 24 500 kg (53 998 lb)
• Maximum weight at takeoff: 29 700 kg (65 458,8 lb)
• Motriz plant: 4× turbo overcharged 9-cylinder radial motor in single star Wright R-1820-97 Cyclone.
  • Power: 895 kW (1200 HP; 1217 CV) each.
• Propellers: Hamilton-Standard Constant Speed Triple
• Elongated length: 7.57

Performance

• Maximum operating speed (Vno): 462 km/h (287 MPH; 249 kt)
• Cruise speed (Vc): 293 km/h (182 MPH; 158 kt)
• Scope: 3219 km (1738 nmi; 2000 mi) with a 2700 kg pump load
• Flight board: 10 851 m (35 600 ft)
• Promotional regime: 4.6 m/s (900 ft/min)
• Long load: 185.7 kg/m2 (38 lb/ft2)
• Power/weight: 150 W/kg

Weaponry

Related aircraft

Related Developments

Similar Aircraft

Designation sequences

• Sequence Numerical (interna de Boeing): ← 280 - 281 - 294 - 299 - 300 - 306 - 307 →
• Sequence B-_ (USAAC/USAAF/USAF, 1926-1962): ← B-14 - B-15 - B-16 - B-17 - B-18 - B-19 - B-20 →
• Sequence BQ-_ (Unmanned U.S.A.A.A. aircraft (controlling bombs, 1942-1945)): ← BQ-4 - BQ-5 - BQ-6 - BQ-7 - BQ-8
• Sequence CQ-_ (USAAF Air White Controllers, 1942-1948): CQ-1 - CQ-2 - CQ-3 - CQ-4
• Sequence P_B (American Navy Patrol aircraft, 1922-1962 (Boeing, 1923-1962)): XPB - PB - P2B - P3B
• Sequence F-_ (USAAC/USAAF/USAF recognition aircraft (Prefix F-), 1930-1948): ← F-6 - F-7 - F-8 - F-9 - F-10 - F-11 - F-12 →