B-17 Flying Fortress
The American Boeing B-17 Flying Fortress was the first mass-produced, four-engine heavy bomber. It was most widely used for daylight strategic bombing of German industrial targets during World War II as part of the United States Eighth Air Force based in England and the Fifteenth Air Force based in Italy.| B-17 Flying Fortress | |
|---|---|
 | |
| USAAF B-17G-30-DL on a bomb run. Photo from Maxwell Air Force Base website. | |
| Type | Strategic bomber |
| Manufacturer | Boeing |
| Maiden flight | July 28, 1935 |
| Introduced | 1938 |
| Retired | 1958, Israeli Air Force |
| Status | Flying |
| Primary user | United States Army Air Force |
| Produced | 1936-1945 |
| Number built | 12,700 |
| Variants | XB-38 YB-40 |
Design and 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, the Model 299 competed with the Douglas DB-1 and Martin Model 146 for a U.S. Army Air Corps contract to build a "multi-engined" bomber. At that time "multi-engined" generally meant two engines. The four-engine Boeing design displayed superior performance, but Army officials were daunted by the much greater expense per aircraft. The Army ordered the two-engine Douglas B-18 Bolo as it was less expensive than the Boeing Model 299.
Development continued on the Boeing Model 299 and on October 30, 1935, the Army Air Corps test pilot Ployer Hill took the Model 299 on a second evaluation flight. The flyers forgot to disengage the airplane's "gust lock"— a device that holds the bomber's movable control surfaces in place while the plane was parked on the ground; the aircraft took off, entered a steep climb, stalled, nosed over and crashed.[1] Regardless, the USAAC had been impressed by the prototype's performance, and, in January 1936, the Air Corps ordered thirteen YB-17s with a number of significant changes from the Model 299, most notably more powerful Wright R-1820-39 Cyclone engines, alongside 99 B-18s (successor of the DB-1).The main structural and flight control problems with the B-17 didn't get resolved until the redesign (after a U.S. California flight accident revealed the problems) with the introduction of the Dorsel Fin and Pilot Instrument secondary engine feedback with the B-17 Flying Fortress Model E.The Dorsel Fin addition greatly enhanced its flight charachteristics and also its structural integrity. It was reputedly much easier to fly than its contemporaries, the B-24 and Avro Lancaster.
The first B-17s went into service in 1938. Immediately following the attack on Pearl Harbor, relatively few B-17s were in use by the Army but production quickly accelerated. The aircraft served in every World War II combat zone. By the time production ended in May 1945, 12,700 aircraft had been built by Boeing, Douglas and Vega (a subsidiary of Lockheed).
Operational service
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 name 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 first use of the B-17 (the B-17C) as the Fortress I in service with the RAF was against Wilhelmshaven on 8 July 1941. By September, the RAF had lost eight to combat or accidents. They had also uncovered problems with flying it at high altitudes (about 30,000 ft). What made the B-17 and other USAAF bombers effective at level bombing from high altitudes was the use of the then secret Norden Bombsight which was essentially a optical electo-mechanical gyrostabilized computer that computed input variables by the bombardier which determined the point in space at which the bombers ordnance type would be released to hit the target (A.P.) during daylight bombing missions and sorties. The bombardier essentially took over flight control of the bomber during the bomb run. The USAAF strategy was to use daylight precision bombing of targets whereas RAF Bomber Command resorted to nighttime area bombing.
Before the advent of long-range fighter escorts, B-17s had only their .50 caliber Browning M2 Machine Guns to rely on for defense for the bombing runs over Europe. To address this problem, the United States developed a 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. However, the use of this rigid formation meant that individual planes could not engage in evasive maneuvers: they had to always fly in a straight line which made them vulnerable to the German antiaircraft 88 mm gun. Additionally, German fighter planes 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 (see Raid on Schweinfurt) and it wasn't until the advent of an effective long-range fighter escort—the P-51 Mustang—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. 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 from veterans abound of B-17s returning to base with tails having been destroyed, with only a single engine functioning or even large portions of wings having been clipped 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 one of the most significant bomber aircraft of the war.
The plane's extreme durability and powerful defensive arcs led the Luftwaffe to develop a number of innovative (and costly) methods of combating the bomber. Late in the war, the Me-262 was to see the most (proportional) success against B-17s. However this success did not come from gun-to-gun combat. While the Me-262 could fly extremely fast, it had to slow down to accurately aim its guns, placing the fighter in the crosshairs of the B-17's many guns. Instead, Me-262s would engage at long distances, firing masses of rockets at the B-17 formations. While this tactic was successful, it came too late in the war, by which time, there were too many B-17s and too few Me-262s to make a real difference. The actual number of B-17s lost to Me-262s using this tactic was low.
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 .50 caliber Browning M2 Machine Guns under the nose. This eliminated the B-17's main defensive weakness of head-on attacks.
Postwar history
Following World War II, the B-17 was declared obsolete and the Army Air Force retired most of the fleet. Flight crews ferried the bombers back across the Atlantic to the United States, where the majority were melted down and sold for scrap. The USAF Strategic Air Command had B-17 Flying Fortresses, (called F-9s at first (F=Fotorecon), later RB-17s) in service from 1946 through 1951. A number of B-17s survive in museums and at airports. About a dozen of these still fly, visiting airports or performing in airshows. Most of these survivors are surplus or training aircraft, which stayed in the U.S. during World War II. However, there are a few exceptions.
The "Memphis Belle," which flew 25 missions over Europe before touring the United States to advertise war bonds, was preserved in Memphis from 1948 to 2003. The "Memphis Belle" was transported to Wright-Patterson Air Force Base in October 2005 for restoration and eventual display at the National Museum of the United States Air Force there. According to the museum [1], the restoration is expected to take 8-10 years.
"The Swoose," the only surviving example of the narrow-tailed 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. The oldest surviving B-17 in the world, "The Swoose" 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. Col. Frank Kurtz, commanding officer of the 463rd Bombardment Group at the Celone Airbase near Foggia,Italy and the father of actress Swoosie Kurtz, 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."
Another noteworthy combat veteran is "Shoo Shoo Shoo Baby," which flew 24 combat missions from England with the 91st Bomb Group before being forced to land in Sweden in May 1944. Sweden, which was neutral, interned the crew. About the same time, a deal was made between the Swedish and US Governments to allow about 300 American crewmen to return in exchange for nine B-17F and G that had landed intact in Sweden. Seven of these were converted by SAAB Aircraft into airliners that could take 14 passengers.
"Shoo Shoo Shoo Baby" became SE-BAP, flying for SILA, an airline that eventually became a part of Scandinavian Airlines (SAS). In December 1945 it was one of two B-17s sold to the Danish Air Lines (DDL), and flew as OY-DFA "Stig Viking" to June 1947. The B-17 was subsequently transferred in March 1948 to Danish Army Air Corps as DAF 672, and in December 1949 to the Danish Navy. Then from October 1952 to the Royal Danish Air Force as ESK-721, it finally retired a year later. In all its service time in the Danish military, her nickname was "Store Bjørn." After two years in storage, she was sold as F-BGSP to IGN, Institut Geographique National, a French aerial mapping company based in Creil outside Paris. Last flown in July 1961, the remains of the plane were donated to the U.S Air Force in 1972. A restoration was undertaken between 1978-1988 at Dover Air Force Base, Delaware and the bomber can be seen today at the National Museum of the United States Air Force in Dayton, Ohio. The Museum has announced that when the "Memphis Belle" restoration is complete, it will replace "Shoo Shoo Shoo Baby" as the museum's B-17 exhibit.
It has also been recently discovered that the B-17G at the March Field Air Museum in Riverside, California was delivered to the 15th Air Force and most likely flew combat missions over North Africa and in the Mediterranean (which was confirmed by battle damage found after the plane was paint stripped during restoration). The exact details of that plane's service, though, are not yet known.
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 15 July 1942 as part of Operation Bolero. 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."
"My Gal Sal" (41-9032), a B-17 from another ferry flight in Operation Bolero that was forced to ditch, has also been recovered. It is being restored to a static configuration in Cincinnati.
Several B-17s and other World War II bombers were converted into airliners. Other B-17s saw extended and gallant service as converted aerial tankers used for fighting forest fires in the western United States.
Variants/design stages
The B-17 went through several alterations 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 "B-17E" 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 definitive version of the B-17. In total, 8,680 were built with many examples 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 XB-38 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 than a fully loaded B-17F. Unfortunately, the YB-40s with their numerous heavy modifications had trouble keeping up with empty bombers. The project was abandoned with the advent of the P-51 Mustang and was phased out in July 1943.
Late in the Second World War, 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-17s. Some of these weapons included "razons" (radio guided) glide bombs, and JB-2 Thunderbugs - the equivalent of the German V-1 Buzz Bomb.
Operators
- Bolivia
- Brazil
- Canada
- Republic of China
- Denmark
- Dominican Republic
- France
- Israel
- Portugal
- United Kingdom
- United States
The B-17 was a versatile aircraft, serving in dozens of units in theaters 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 Theater. Only five B-17 groups operated in the Pacific, with a peak of 168 bombers in September 1942, and all groups converting to other types by mid-1943. Thirty-two groups were stationed in Europe, twenty-six in England and six in Italy. Peak USAAF inventory (in August 1944) was 4,574 worldwide.
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) were known to the RAF as "Fortress I"s. The British already operated the more capable Avro Lancaster and were reluctant to use the B-17 for its original mission profile of heavy bombing. The British regarded the early B-17 as inefficient, due to its larger crew and relatively small bomb load compared to the Avro Lancaster. 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, after crash-landing or being forced down, approximately 40 B-17s were repaired and put back into the air in the service of the Luftwaffe. These captured aircraft were codenamed "Dornier Do 200," given German markings and used for clandestine spy and reconnaissance missions by the Luftwaffe-most often used by the Luftwaffe unit known as KG 200, hence a likely possibility as a source for the "Dornier Do 200" codename.
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 due to defective oxygen equipment) but caused little damage to the target. The B-17s were generally unsuitable for the 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 IAF. They were withdrawn in 1958.
Noted B-17 pilots
- Martin Caidin - author of Cyborg the story that formed the basis of The Six Million Dollar Man
- Werner G. Goering, American-born nephew of Nazi Reichsmarschall Hermann Goering, Commander of the German Luftwaffe.
- Colin Kelly - pilot of first US B-17 lost in action
- Immanuel J. “Manny” Klette, second-generation German-American whose 91 combat missions were the most flown by any Eighth Air Force pilot in World War II.
- Frank Kurtz - Olympic medalist 1932,1936 and Pearl Harbor attack survivor
- Tom Landry - American football player and coach
- Curtis LeMay - later head of the Strategic Air Command and head of the USAF
- Robert Morgan - pilot of Memphis Belle
- Gene Roddenberry - creator of Star Trek
- Robert Rosenthal
- Jimmy Stewart - the film actor
- Bert Stiles - short story author
- Paul Tibbets - pilot for the first atomic bombing
- Robert Webb
- Smokey Yunick - motorsports car designer
Noted B-17 crew members
- Clark Gable, gunner
- Norman Lear, radio operator
Notable B-17s
- All American
- Aluminum Overcast[[2]]
- Big Yank
- Brennan's Circus
- Day's Pay
- Lassie and her lads
- Liberty Belle
- Memphis Belle
- Nine-O-Nine
- Piccadilly Lily
- The Pink Lady
- Sally B
- Sentimental Journey
- Sweet Pea
- The Swoose
- Thunder Bird
Quotes
"Without the B-17, we might have lost the war."
–General Carl Spaatz, Commander, U.S. Strategic Air Forces in Europe, 1944
"She was a Stradivarius of an airplane..."
–Colonel Robert Morgan, the man who flew the Memphis Belle.
"The plane can be cut and slashed almost to pieces by enemy fire and bring its crew home."
–Wally Hoffman, B-17 Pilot, 8th Air Force, WWII[2]
"This B-17 met a head-on attack by three Focke-Wulf FW-190 fighters. The gunners exploded two of them, and the top turret poured a stream of shells into the cockpit of the third. With a dead man at the controls, the fighter screamed in, and at a closing speed of 550 miles per hour smashed head on into the number-three engine.
The tremendous impact of the crash tore off the propeller. It knocked the heavy bomber completely out of formation as though a giant hand has swatted a fly. The fighter cartwheeled crazily over the B-17. It cut halfway through the wing, and then sliced a third of the way through the horizontal stabilizer. The top and ball turrets immediately jammed, the radio equipment was smashed to wreckage, and all the instruments 'went crazy.' Pieces of metal from the exploding, disintegrating Focke-Wulf tore through the fuselage, and a German gun barrel buried itself in the wall between the radio room and the bomb bay.
Crews of nearby bombers watched the collision. They saw a tremendous explosion, and the bomber hurtling helplessly out of control, tumbling as she fell. They reported when they returned to base that the Flying Fortress had blown up, and that the crew must be considered dead.
The old Queen hadn't blown up, and the crew was far from dead. The pilots struggled wildly in the cockpit, and somehow between them managed to bring their careening bomber back under control. The gunners shot down a fourth fighter that had closed in to watch the proceedings.
And then they brought her all the way back to England, and scraped her down for a belly landing on the runway.
Postscript: not a man was injured."
–Martin Caidin, in his book Black Thursday[3]Specifications (B-17G)
Data from USAF Museum[4]
General characteristics
- Crew: 10: Pilot, co-pilot , navigator, bombardier/nose gunner, flight engineer-top turret gunner, radio operator, waist gunner X 2, ball turret gunner, tail gunner
- Length: 74 ft 9 in (22.7 m)
- Wingspan: 103 ft 10 in (31.6 m)
- Height: 19 ft 1 in (5.8 m)
- Wing area: 1,420 ft² (131.9 m²)
- Airfoil: NACA 0018 / NACA 0010
- Empty weight: 36,135 lb (16,390 kg)
- Loaded weight: 54,000 lb (24,495 kg)
- Max takeoff weight: 72,000 lb (32,660 kg)
- Powerplant: 4× Wright R-1820-97 "Cyclone" turbosupercharged radial engines, 1,200 hp (900 kW) each
Performance
- Maximum speed: 287 mph (249 knots, 462 km/h)
- Cruise speed: 150 mph (130 knots, 240 km/h)
- Range: 1,610 nm (1,850 mi, 2,980 km)
- Service ceiling: 35,600 ft (10,850 m)
- Rate of climb: 900 ft/min (4.6 m/s)
- Wing loading: 38.0 lb/ft² (185.7 kg/m²)
- Power/mass: 0.089 hp/lb (150 W/kg)
Armament
- Guns: 13× Browning M-2 0.50 calibre (12.7 mm) machine guns (with optional extra nose armament fitted in glazed nose)
- Bombs:
- Short range missions (<400> 8,000 lb (3,600 kg) on short-range missions
- Long range missions (≈800 mi): 4,500 lb (2,000 kg) on long-range missions
- Maximum Reported B-17 & B-24 Bomb Loads
B-17 Flying Fortress Serial Numbers
Type List 1 List 2 List 3 List 4 List 5 Where Produced Y1B-17 36-149 to 36-161 Y1B-17A 37-369 B-17B 38-211 to 38-223 38-258 to 38-270 38-583 and 38-584 38-610 39-1 to 39-10 B-17C 40-2042 to 40-2079 B-17D 40-3059 to 40-3100 B-17E 41-2393 to 41-2669 41-9011 to 41-9245 B-17F-BO 41-24340 to 41-24639 42-5050 to 42-5484 42-29467 to 42-31031 Boeing B-17F-DL 42-2964 to 42-3482 Douglas B-17F-VE 42-5705 to 42-6204 Vega B-17G-BO 42-31032 to 42-32116 42-97058 to 42-91407 42-102379 to 42-102978 43-37509 to 43-39508 Boeing B-17G-DL 42-3483 to 42-3563 42-37714 to 42-38213 42-106984 to 42-107233 44-6001 to 44-7000 44-83236 to 44-83885 Douglas B-17G-VE 42-39758 to 42-40057 42-97436 to 42-98035 44-8001 to 44-9000 44-85492 to 44-85841 Vega XB-40 41-24341 YB-40 42-5732 to 42-5744 42-5871 42-5920 and 42-5921 42-5923 to 42-5925 42-5927 TB-40 42-5833 and 42-5834 42-5872 42-5926 
Nuthampstead, England. Aircraft mechanics with the 398th Bombardment Group change a B-17 Flying Fortress engine here. During the group's stay in England from May 1944 to April 1945, the 398th flew 195 missions and lost 292 men and 70 B-17 aircraft in combat.
No comments:
Post a Comment