B-17 Flying Fortress: Encyclopedia - B-17 Flying Fortress

B-17 Flying Fortress

The Boeing B-17 Flying Fortress was the first mass-produced, four-engine heavy bomber. It was most widely used for daylight strategic bombings of German industrial targets during World War II as part of the United States Eighth Air Force.

B-17 Flying Fortress - Development

The prototype B-17 first flew on July 28 1935 as the Boeing Model 299, with Boeing chief test pilot Les Tower at the controls. During a demonstration later that year at Wright Field in Dayton, Ohio, Model 299 competed with the Douglas DB-1 and Martin Model 146. While the Boeing design was obviously superior, Army officials were daunted by the much greater expense per aircraft. October 30th of 1935 the Army Air Corps test pilot Ployer Hill took the Model 299 on a second evaluation flight. The flyers forgot to disengage the plane's "gust lock"--a device that holds the bomber's movable control surfaces in place while the plane was parked on the ground--and the aircraft took off, entered a steep climb, stalled, nosed over, and crashed. [1]. In January of 1936, the Air Corps ordered thirteen YB-17s with a number of significant changes from the Model 299, most notably that of the engines to more powerful Wright R-1820-39 Cyclones, next to 99 B-18s (successor of the DB-1).

The first B-17 went into service in 1938. By December 7 1941, few B-17s were in use by the Army. Following the attack on Pearl Harbor, production was quickly accelerated. The aircraft served in every World War II combat zone. Production ended in May 1945 after 12,700 aircraft had been built.

B-17 Flying Fortress - Operational history

The name "Flying Fortress" was coined by Richard Williams, a reporter for the Seattle Times who gave this name to the Model 299 when it was rolled out showing off its machine gun installations. Boeing was quick to see the value of the title and had it trademarked for use. Among the combat aircrews that flew bombers in World War II, noted aviation writer Martin Caidin reported that the B-17 was referred to as the "Queen of the Bombers."

The B-17 was noted for its ability to take battle damage, still reach its target and bring its crew home. It reportedly was much easier to fly than its contemporaries, and 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.

The design went through eight major changes over the course of its production, culminating in what some consider the definitive type, the B-17G, differing from its immediate predecessor by the addition of a chin turret with two 0.50 calibre (12.7 mm) machine guns under the nose. This eliminated the aeroplane's main defensive weakness of head on attacks.

B-17 Flying Fortress - Variants/Design stages

The B-17 went through several iterations in each of its design stages and variants. Of the thirteen YB-17s ordered for service testing, only one was actually used. Experiments on this plane led to the use of a turbo-supercharger, which would become standard on the B-17 line. When this aircraft was finished with testing, it was redesignated the B-17A, and was the first plane to enter service under the B-17 designation.

As the production line developed, Boeing engineers continued to improve upon it. To improve performance, the original design was altered to include larger flaps. Most significantly, with the 'E' version the fuselage was extended by 10 feet, 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. Similarly, the gun stations were altered on numerous occasions to enhance their effectiveness.

By the time the B-17G appeared, the number of guns had been increased from seven to thirteen, the designs of the gun stations were finalised, and other adjustments were complete. In this the G model incorporated all changes made in its predecessor, the B-17F. The B-17G is generally considered the defining version of the B-17. Some 8680 were built, Many were converted for other missions, such as cargo hauling, engine testing and reconnaissance.

Two versions of the B-17 were flown under different designations. These were the XB-38 and the YB-40. The former was an engine test bed for Allison V-1710 liquid-cooled engines, to test the engine should the Wright engines normally used on the B-17 become unavailable. The YB-40 was a modification of the standard B-17 used before the P-51 Mustang became available. Since no fighters had the range to escort the B-17, a heavily armed modification was used instead with an additional 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 pounds (4,500 kg) heavier then that of a fully loaded B-17F. Unfortunately, the YB-40s with their numerous heavy modifications had trouble keeping the pace with empty bombers. The project was abandoned with the advent of the P-51 Mustang and was phased out in July of 1943.

Late in World War II, at least 25 B-17s were fitted with radio controls, loaded with 12,000 lb (5443 kg) of high explosives, dubbed 'BQ-7 Aphrodite missiles,' and used against U-boat pens and bomb-resistant fortifications. Because few (if any) BQ-7s hit their target, the Aphrodite project was scrapped in early 1945. History of the BQ-7 During and after World War II, a number of weapons were tested and used operationally on B-17's. Some of these weapons included razons (radio guided), glide bombs, and JB-2 Thunderbugs - the equivalent of the German V-1 Buzz Bomb.

B-17 Flying Fortress - Units Using the B-17

The B-17 was an ubiquitous aircraft, and it served in dozens of units in theatres of combat throughout World War II. 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 Theatre. Only three B-17 groups were stationed in the Pacific, but dozens were stationed in Europe.

It was also used by the Royal Air Force, though mainly in roles other than those for which it had been designed. The first B-17s, -C and -D models — known to the RAF as "Fortress I"s — used by the Royal Air Force had been tragic disasters, and despite its overwhelming success in American hands, the British were reluctant to use the B-17 for its original mission profile of heavy bombing. They regarded the B-17 as uneconomical, due to its larger crew and relatively small bomb load. Instead, they used them for patrol bombing, and later equipped a number of them with sophisticated radio-countermeasures equipment, where they served in some of the first electronic countermeasures operations with RAF 100 Group.

During World War II, some forty B-17s were repaired by the Luftwaffe after being crash-landed or forced down and put back in the air in the service of the Reich. These were codenamed "Dornier Do 200," given German markings to disguise their origin and were used for clandestine spy and reconnaissance missions by the Luftwaffe. Other B-17s retained their Allied markings and were used to to infiltrate B-17 formations, then report their position and altitude to German ground-control stations. The practice was intially successful, but it did not take the Army Air Force combat aircrews long to figure out what was happening. Standard procedure shortly became to first warn off, and then fire upon, any 'stranger' trying to join a group's formation.

When Israel achieved statehood in 1948, the Israeli Air Force had to be assembled quickly to defend the new nation from the war it found itself embroiled in almost immediately. Among the first aircraft acquired by the Israeli Air Force were three surplus American B-17s, smuggled via South America and Czechoslovakia to avoid an arms trading ban imposed by the United States. A fourth plane was captured and confiscated by American officials. In their delivery flight from Europe, the aircraft were ordered to bomb the Royal Palace of King Farouk in Cairo before continuing to Israel, in retaliation for Egyptian bombing raids on Tel-Aviv. They performed the mission (despite some of the crew fainting alternately due to defective oxygen equipment) but caused little damage to the target. The B-17s were generally unsuitable for the ideal needs of the Israeli Air Force and the nature of the conflict, in which long-range bombing raids on large-area targets were relatively unimportant. They were mainly used in the 1948 Arab-Israeli War, flown by 69 Squadron Israeli Air Force. They saw more limited usage until being phased out in 1958.

B-17 Flying Fortress - Obsolescence

Following World War II, the B-17 was declared obsolete and the Army Air Force retired the B-17 fleet. Flight crews ferried the bombers back across the Atlantic to the United States, where they were melted down and sold for scrap.

A number of B-17s survive in museums and at airports. A handful of these still fly, visiting airports or performing in airshows. Since the bombers that served in World War II were sold for scrap, these survivors are surplus or training aircraft, which stayed stateside during the War. However, there are two exceptions.

The Memphis Belle, which flew 25 missions over Europe before touring the United States to advertise war bonds, is preserved in Memphis, TN.The Memphis Belle has been transported to Wright Patterson Air Force base for restoration and display. The Dayton Daily News has more information on this move and how you can view the plane during its restoration.

The Swoose, the only survivng example of the narrow-tailed B-17s of the A, B, C and D series, fought in the Pacific Theatre before being converted to an unarmed transport/flying command post used by general officers of the Fifth Air Force in Australia prior to her being ordered back to the United States in 1943. The senior surviving B-17 in the world, she is presently in storage at the Smithsonian Institution's Silver Hill aircraft storage and restoration facility in Maryland. As of 2000, the Smithsonian was planning to restore her, though whether to full airworthiness or to static display standard had not been determined.

Also, two B-17s navigating and acting as mother ships for six P-38 Lightnings were forced to land on a glacier in Greenland during a ferry flight to the UK on July 15, 1942. (Incredibly, none of the crews were lost.) By the 1990s, these eight aircraft had been buried under more than 250 feet of ice. One of the P-38s was recovered and restored as "Glacier Girl." One of the B-17s was also recovered (My Gal Sal, 41-9032), but it remains dismantled in storage in Cincinnati, OH. None of the 'Lost Squadron' ever saw combat, however.

B-17 Flying Fortress - Noted B-17 pilots

• Robert Morgan
• Gene Roddenberry
• Robert Webb

B-17 Flying Fortress - Specifications B-17G

B-17 Flying Fortress - General characteristics

• Crew: 10
• Length: 74 ft 4 in (22.7 m)
• Wingspan: 103 ft 10 in (31.6 m)
• Height: 19 ft 1 in (5.8 m)
• Wing area: 1527 ft² (141.9 m²)
• Empty: 36,135 lb (16,390 kg)
• Loaded: 54,000 lb (24,494 kg)
• Maximum takeoff: 72,000 lb (32,659 kg)
• Powerplant: 4× Wright R-1820-99 turbo-supercharged radials, 1,200 hp (895 kW)

B-17 Flying Fortress - Performance

• Cruise speed: 170 mph ((273 km/h)
• Maximum speed: 300 mph (483 km/h)
• Loaded Range: 1,850 miles (2,977 km)
• Service ceiling: 35,600 ft (10,900 m)
• Loaded Rate of climb: 200ft/min ( m/min)
• Wing loading: 47.2 lb/ft² (231 kg/m²)
• Power/mass: 0.0655 hp/lb (110 W/kg)

B-17 Flying Fortress - Armament

• 13× Browning M-2 0.50 calibre (12.11 mm) machine guns (with optional extra nose armament fitted in glazed nose)
• 8,000 lb (3,600 kg) of bombs long range
• 17,600 lb (7,983 kg) of bombs short range

B-17 Flying Fortress - Related content

Designation sequence:

• Military: XB-14 - XB-15 - XB-16 - B-17 - B-18 - XB-19 - Y1B-20
• Boeing: 266 - 281 - 294 - 299 - 307 - 314 - 316

Related development:

• Boeing XB-15
• XB-38 Flying Fortress
• YB-40 Flying Fortress

Similar aircraft:

• Avro Lancaster
• B-24 Liberator
• Handley-Page Halifax

Related lists:

• List of bomber aircraft
• List of military aircraft of the United States

External links:

• Encyclopedia of American Aircraft
• USAF Museum
• Fantasy of Flight's B17 B-17 Flying Fortress on display at Fantasy of Flight
• Memphis Belle (1990) at the Internet Movie Database
• The Memphis Belle A Story of a Flying Fortress (1944) at the Internet Movie Database
• Combat America:The B-17 Story - Watch real combat footage in color from WWII

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Category: U.S. bomber aircraft 1930-1939

Adapted from the Wikipedia article "B-17 Flying Fortress", under the G.N U Free Docmentation License. Please also see http://en.wikipedia.org/wiki