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Boeing B-17 Flying Fortress Heavy Bomber (1937)

Authored By Staff Writer | Last Updated: 10/19/2014

The legendary Boeing B-17 Flying Fortress accounted for over 290,000 sorties with 640,000 tons of ordnance dropped during World War 2.

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Though the Consolidated B-24 Liberator was built in greater numbers, the Boeing B-17 Flying Fortress is often regarded as the more important heavy bomber for the American Allies in the Second World War, accounting for over 290,000 sorties against ground installations and dropping over 640,000 tons of bombs. By war's end, the B-17 Flying Fortress was a mainstay in both the Pacific and European Theaters of War. The system became the symbol of American bomber might in the Second World War and continues with its legendary status even today. Incidentally, the name "Flying Fortress" is purported to have come from one of the reporters present during the unveiling of the machine at the Boeing plant, remarking as to how the aircraft looked like a 15-ton "flying fortress".

Designed to a US requirement for a four-engine bomber capable of long distance travel with a full 2,000lb bombload and reach speeds between 200 and 250 miles per hour. The result was the Boeing Model 229 which first flew in 1934, though was later lost to pilot error. Nevertheless, the US Army Air Corps pursued the design with an order for further developmental models fitted with differing powerplants. Early B-17 models were mostly developmental production variants that included the additions of seal-sealing fuel tanks, better armor protection and a redesigned tail. The initial definitive Flying Fortress model would arrive with 512 examples of the B-17E model which were the first to incorporated the twin .50 caliber tail armament for defense. This model was followed by the similar B-17F models of which 3,405 were produced. This latter model featured revised defensive armament positions. Often regarded as the ultimate B-17 production model, the B-17G featured the identifiable and effective Bendix powered chin turret fitted with 2 x 12.7mm machine guns under the nose. Revised turbochargers and an increase to 13 .50 caliber machine guns also arrived with this G model. In the end, the B-17G would account for over 8,600 units with production split between Boeing (4,035 samples), Douglas (2,395 samples) and Lockheed Vega (2,250 samples).

B-17 Flying Fortresses followed common practice in that they flew in what was known as the "box formation". This formation allowed every gunner on board the aircraft to bring their guns to bear to any position needed. Gunner positions on the B-17 included a top turret gunner manning 2 x 12.7mm machine guns, a tail gunner manning 2 x 12.7mm machine guns, a belly gunner manning 2 x 12.7mm machine guns, 2 x cheek gun emplacements, staggered waist gunner positions each manning a single 12.7mm machine gun and the Bendix chin turret. A limited-arc-of-fire, single 12.7mm machine gun position at the radio operators area was available in early models but later removed. The flight engineer doubled as the top turret gunner while the bombardier and navigator in the nose section doubled as front gunners. The belly turret gunner was generally of a small stature to be able to fit into the limited-space turret system. All positions were afforded some type of built-in armor protection but this varied extensively by position.

The bombardier and navigator were awarded the best views of the sky through the large plexiglas nose. The bombardier sat on a type of swiveling stool with the fabled Norden Bombsight before him. The navigator sat off-set to his rear at a small map-filled desk. Both were supplied with defensive .50 caliber machine guns with the Bendix chin turret under the bombardiers control in the G model and onwards. Access to the nose was accomplished through a smallish passage way underneath the main flight deck.

The pilot and co-pilot sat on the flight deck above and behind the navigator's position with the pilot to the left and his copilot to the right with both offered equal control access and views of all four of the engines. To their rear was the top gunners position with a catwalk crossing between the payload in the bomb bay. Once past the bomb bay, the radio operators station and his equipment was apparent. The radio operator was also afforded a table and seating along with his communications equipment. Access to the belly turret was available following this area, which further opened up to the staggered waist gunner positions which might or might not have been covered by plexiglass depending on the model.

Though not added until the production E models, the tail gunner arguably served the single most important deterrent to enemy aircraft as enemy pilots tended to attack formations from the rear, starting with the last aircraft in the line known to American crews as "Tail End Charlie". Like the belly turret gunner, the tail turret operator made his way to his rearward position after the aircraft was in flight and connected to his oxygen supply and intercom system. He held a kneeling position (sitting on his legs) and manned a limited arc-of-fire twin machine gun system that was improved with the "Cheyenne" turret in G models. This new turret offered up a greater field of fire and improved gun sighting.

Overall, the B-17 Flying Fortress was a utilitarian vehicle that was - for the most part - cramped, gusty and produced the various smells inherent in a machine of this type, from burning rubber to spent shell casings. The Fortress was a noisy place to "work" yet crew after crew found a home in the aircraft that were to become their livelihoods through the duration of the war. The aircraft served a purpose and her crews made the most of it with what was provided to them.

RAF forces took several B-17 models with their applied "Fortress 1", "Fortress 2" and "Fortress 3" designations, utilizing some in the electronic countermeasures role. Reconnaissance variants appeared with the US Army Air Corps, US Navy and US Coast Guard as well, each with differing designations shown below. In any case, its heavy use showcased the versatility of the airframe and the importance of the aircraft to the Allied air cause.

The B-17 is often remembered for the myriad of colorful names and nose art identifiers that included the famous "Memphis Belle", which became one of the first B-17's to complete a full tour of duty before being sent back to the States with her crew for war bond drives. The aircraft became a favorite of aircrews for her ability to withstand a tremendous amount of damage and keep flying. In a bit of B-17 trivia, the massive flight formations of Imperial Navy Japanese fighters and torpedo planes discovered for the attack at Pearl Harbor on December 7th were mistaken as an incoming flight of scheduled B-17 Flying Fortresses from the mainland.

As quickly as the B-17 arrived it was gone in the after-war years. Some survived as developmental or specialized role models but many were scrapped by the arrival of the jet age. Some survived for museum use while others were refurbished and continue to fly today with dedicated aviators and traveling flight troupes. In any case, the system will long outlive her users and forever be carried on through history through astonishing tales of heroism, feats and ultimately success over the Third Reich and Imperial Japan.

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Specifications for the
Boeing B-17 Flying Fortress
Heavy Bomber


Focus Model: Boeing B-17G Flying Fortress
Country of Origin: United States
Manufacturer: Boeing Company / Douglas Aircraft / Lockheed Vega - USA
Initial Year of Service: 1937
Production: 12,731


Crew: 10


Length: 74.74 ft (22.78 m)
Width: 103.74 ft (31.62 m)
Height: 19.09ft (5.82 m)
Weight (Empty): 36,136 lb (16,391 kg)
Weight (MTOW): 72,003 lb (32,660 kg)


Powerplant: 4 x Wright Cyclone R-1820-97 radial piston engines generating 1,200 hp each.


Maximum Speed: 287 mph (462kmh; 249 kts)
Maximum Range: 2,001 miles (3,220km)
Service Ceiling: 35,597 ft (10,850 m; 6.7 miles)
Rate-of-Climb: 541 feet per minute (165 m/min)


Hardpoints: 0
Armament Suite:
STANDARD (Primary Models):
2 x 12.7mm machine guns in powered dorsal turret
1 x 12.7mm machine gun in left-front "cheek" position.
1 x 12.7mm machine gun in right-front "cheek" position.
1 x 12.7mm machine gun in left waist position
1 x 12.7mm machine gun in right waist position
1 x 12.7mm machine gun at radio operator station (removed on later models).
2 x 12.7mm machine guns in powered belly turret
2 x 12.7mm machine guns in tail gun position

B-17G (In Addition to Above):
2 x 12.7mm machine guns in powered chin turret

OPTIONAL:
Maximum internal bombload of 7,983 kg (17,600 lbs).


Variants:
Model 299 - Boeing Model Test Aircraft; fitted with 4 x Pratt & Whitney 750hp engines; later lost to an accident attributed to human error.


Y1B-17 - Thirteen ordered for further development; later redesignated to B-17.

Y1B-17A - Engine test aircraft (only one produced); later redesignated to B-17A model.

B-17B - First production model

B-17C - 38 such samples produced and fitted with 4 x Wright Cyclone engines generating 1,200hp each.

B-17D - Similar to C production model to which all existing C models were brought up to D model standard.

B-17E Mass production model; Enlarged tail section.

B-17F - Improved defensive armament

B-17G - Improved variant; Bendix chin turret implemented.

B-17H - Modified air-sea rescue conversions; fitted with rescue equipment.

Fortress I - B-17C models as supplied to the RAF in 1941.

Fortress IIA - B-17E models as supplied to the RAF in 1942.

Fortress III - B-17G models as supplied to the RAF.

F-9C - B-17G models converted for reconnaissance; ten such models utilized.

PB-1W - US Navy / Coast Guard maritime surveillance models of which 24 were utilized.

PB-1G - US Navy / Coast Guard maritime surveillance models of which 16 were utilized.

TB-17H - Modified air-sea rescue conversions; fitted with rescue equipment.


Operators:
Argentina; Bolivia; Brazil; Canada; Colombia; Denmark; Dominican Republic; France; Nazi Germany; Iran; Israel; Japan; Mexico; Nicaragua; Peru; Portugal; South Africa; Taiwan; Soviet Union; Sweden; United Kingdom; United States