Editing Boeing B-17 Flying Fortress (section)

== Operational history ==
[[File:B-17E 19 BG.jpg|thumb|Boeing B-17E Flying Fortress of the 19th Bombardment Group USAAF, summer 1942]]

The B-17 began operations in World War&nbsp;II with the [[Royal Air Force]] (RAF) in 1941, and in the Southwest Pacific with the U.S. Army.

During World War II, the B-17 equipped 32 overseas combat groups, inventory peaking in August 1944 at 4,574 USAAF aircraft worldwide.<ref name="Baugher Squads" /> The British heavy bombers, the [[Avro Lancaster]] and [[Handley Page Halifax]], dropped {{cvt|608612|LT|ST t}} and {{cvt|224207|LT|ST t}}<ref>{{cite web|url=http://www.raf.mod.uk/rafbramptonwytonhenlow/aboutus/handleypagehalifax.cfm|title=Handley Page Halifax|archive-url=https://web.archive.org/web/20080530210057/http://www.raf.mod.uk/rafbramptonwytonhenlow/aboutus/handleypagehalifax.cfm|archive-date=30 May 2008|website=RAF.mod.uk|access-date=4 October 2019}}</ref> respectively.

=== RAF use ===
[[File:Royal Air Force Boeing Fortress Mk.I.jpg|thumb|RAF Fortress I [[United Kingdom military aircraft serials|serial]] ''AN529'', with [[Heinkel He 111|He 111H]]-style "bathtub" ventral [[Gondola (airplane)|gondola]]]]
The RAF entered World War II without a sufficient supply of modern heavy bombers, with the largest available long-range medium bombers in any numbers being the [[Vickers Wellington]], which could carry {{convert|4500|lb}} of bombs.<ref name="Andrews & Morgan p340">Andrews and Morgan 1988, p. 340.</ref> While the [[Short Stirling]] and [[Handley Page Halifax]] became its primary bombers by 1941, in early 1940, the RAF agreed with the U.S. Army Air Corps to acquire 20 B-17Cs, which were given the [[British military aircraft designation systems|service name]] Fortress Mk.I. Their first operation, against [[Wilhelmshaven]] on {{Nowrap|8 July}} 1941 was unsuccessful.<ref name="Yenne.p23" /><ref name="Chant" /> On {{Nowrap|24 July}} three B-17s of [[No. 90 Squadron RAF|90 Squadron]] took part in a [[German battleship Gneisenau#Air attacks in Brest|raid on the German capital ship Gneisenau]] and [[German cruiser Prinz Eugen|Prinz Eugen]] anchored in [[Brest, France|Brest]] from {{cvt|30000|ft}}, to draw German fighters away from 18 [[Handley Page Hampden]]s attacking at lower altitudes, and in time for 79 Vickers Wellingtons to attack later with the German fighters refueling. The operation did not work as expected, with 90 Squadron's Fortresses being unopposed.<ref name="Chorlton p38">Chorlton ''Aeroplane'' January 2013, p. 38.</ref><ref name="hardest p122-3">Richards 1995, pp. 122–23.</ref>{{sfn|Garzke|Dulin|1985|pp=159–60}}

By September, the RAF had lost eight B-17Cs in combat and had experienced numerous mechanical problems,<ref group=Note>problems the RAF found included the tendency to burn when hit, icing problems, crew fatigue due to altitude, oxygen system failures</ref> and [[RAF Bomber Command|Bomber Command]] abandoned daylight bombing raids using the Fortress I because of the aircraft's poor performance. The experience 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. However, the USAAF continued using the B-17 as a day bomber, despite misgivings by the RAF that attempts at daylight bombing would be ineffective.<ref name="Weigley.338" />

As use by Bomber Command had been curtailed, the RAF transferred its remaining Fortress Mk.I aircraft to [[RAF Coastal Command|Coastal Command]] for use as a long-range maritime patrol aircraft.<ref name="Stitt 1" /> These were augmented starting in July 1942 by 45 Fortress Mk.IIA (B-17E) followed by 19 Fortress Mk II (B-17F) and three Fortress Mk III (B-17G). A Fortress IIA from [[No. 206 Squadron RAF]] sank [[U-627]] on {{Nowrap|27 October}} 1942, the first of 11 U-boat kills credited to RAF Fortress bombers during the war.<ref name="Wynn.93" />

As sufficient Consolidated Liberators finally became available, Coastal Command withdrew the Fortress from the Azores, transferring the type to the meteorological reconnaissance role. Three squadrons undertook Met profiles from airfields in Iceland, Scotland, and England, gathering data for vital weather forecasting purposes.

The RAF's [[No. 223 Squadron RAF|No. 223 Squadron]], as part of [[No. 100 Group RAF|100 Group]], operated several Fortresses equipped with an electronic warfare system known as "[[Airborne Cigar]]" (ABC). This was operated by German-speaking radio operators to identify and jam German ground controllers' broadcasts to their [[nightfighter]]s. They could also pose as ground controllers themselves to steer nightfighters away from the [[bomber stream]]s.<ref>{{cite news|url=https://www.telegraph.co.uk/news/main.jhtml?view=DETAILS&grid=&xml=/news/2007/12/13/db1301.xml|archive-url=https://web.archive.org/web/20071214211240/http://www.telegraph.co.uk/news/main.jhtml?view=DETAILS&grid=&xml=%2Fnews%2F2007%2F12%2F13%2Fdb1301.xml|url-status=dead|archive-date=14 December 2007|title=Obituaries: John Hereford|newspaper=[[The Daily Telegraph]]|date=13 December 2007|access-date=8 July 2021}}</ref>

=== Initial USAAF operations over Europe ===
[[File:Marks and letters on the tails of B-17 during WWII in Europe.jpg|thumb|Marks and letters on the tails of B-17 during WWII in Europe]]

The air corps – renamed [[United States Army Air Forces]] (USAAF) on 20 June 1941 – used the B-17 and other bombers to bomb from high altitudes with the aid of the then-secret [[Norden bombsight]], known as the "Blue Ox",<ref>{{cite news |url=https://www.nps.gov/articles/second-generation-norden-bombsight-vault.htm |title=Second-Generation Norden Bombsight Vault |work=[[National Park Service]] |access-date=2 July 2017}}</ref><ref>"Blue Ox." ''National Geographic Magazine'', Vol. LXXXIII, Number One, January 1943, p. 7, Ad(i).</ref> which was an optical electromechanical gyrostabilized [[analog computer]].<ref>Peterson, Paul. ''Ludington Daily News'', 16 April 1994, p. 1.</ref> The device was able to determine, from variables put in by the bombardier, the point at which the bombs should be released to hit the target. The bombardier essentially took over flight control of the aircraft during the bomb run, maintaining a level altitude during the final moments before release.<ref name="Baugher B-17B" />

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 {{Nowrap|12 May}} 1942, to form the 97th Bomb Group.<ref name="Northstar" /> On {{Nowrap|17 August}} 1942, 12 B-17Es of the 97th, with the lead aircraft piloted by Major [[Paul Tibbets]] and carrying [[Brigadier General]] [[Ira Eaker]] as an observer, were close escorted by four squadrons of RAF [[Supermarine Spitfire|Spitfire IXs]] (and a further five squadrons of Spitfire Vs to cover the withdrawal) on the first USAAF heavy bomber raid over Europe, against the large railroad [[Classification yard|marshalling yards]] at [[Rouen]]-Sotteville in France, while a further six aircraft flew a diversionary raid along the French coast.<ref name="WoF p59-0" /><ref name="AAF combat" /> The operation, carried out in good visibility, was a success, with only minor damage to one aircraft, unrelated to enemy action, and half the bombs landing in the target area.<ref>{{citation |chapter-url=http://www.ibiblio.org/hyperwar/AAF/I/AAF-I-18.html |chapter=Chapter 18: Rouen-Sotteville, No. 1, 17 August 1942 |volume=I: Plans & Early Operations, January 1939 to August 1942 |pages=662–63 |date=1975 |orig-date=1948 |first=Arthur B. |last=Ferguson |editor-last1=Craven |editor-first1=W F |editor-last2=Cate |editor-first2= J L |title= [[The Army Air Forces in World War II]] |via=Hyperwar Foundation}}</ref>

Two additional groups arrived in Britain at the same time, bringing with them the first B-17Fs, which served as the primary AAF heavy bomber fighting the Germans until September 1943. As the raids of the American bombing campaign grew in numbers and frequency, German interception efforts grew in strength (such as during the attempted bombing of Kiel on 13 June 1943<ref name="Bowman.7" />), such that unescorted bombing missions came to be discouraged.<ref name="Weigley 339" />

=== Combined offensive ===
[[File:B-17F formation over Schweinfurt, Germany, August 17, 1943.jpg|left|thumb|B-17F formation over [[Schweinfurt]], Germany, {{Nowrap|17 August}} 1943]]

The two different strategies of the American and British bomber commands were organized at the [[Casablanca Conference (1943)|Casablanca Conference]] in January 1943. The resulting "[[Combined Bomber Offensive]]" weakened the [[Wehrmacht]], destroyed German morale, and established air superiority through [[Operation Pointblank]]'s destruction of German fighter strength in preparation for a ground offensive.<ref name="Carey Pointblank" /> The USAAF bombers attacked by day, with British operations – chiefly against industrial cities – by night.<ref>{{Cite web|last=November 1998|first=Brian Todd Carey|date=2006-06-12|title=How Allied Air Attacks Evolved During World War II|url=https://www.historynet.com/how-allied-air-attacks-evolved-during-world-war-ii.htm|access-date=2021-03-24|website=HistoryNet|language=en-US}}</ref>

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.<ref name="Carey Pointblank" /> Attacks began in April 1943 on heavily fortified key industrial plants in [[Bremen]] and [[Recklinghausen]].<ref name="Bowman.8" />

Since the airfield bombings were not appreciably reducing German fighter strength, additional B-17 groups were formed, and 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 [[Schweinfurt-Regensburg mission|first raid]] on {{Nowrap|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. The Germans shot down 36 aircraft 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.<ref name="Hess.pp59-60" />

A second attempt on Schweinfurt on 14 October 1943 later came to be known as "[[Second Raid on Schweinfurt|Black Thursday]]".<ref name="Hess.pp65-67" /> While the attack was successful at disrupting the entire works, severely curtailing work there for the remainder of the war, it was at an extreme cost.<ref name="Bowman.22" /> Of the 291 attacking Fortresses, 60 were shot down over Germany, five crashed on approach to Britain, and 12 more were scrapped due to damage&nbsp;– a loss of 77 B-17s.<ref name="AFM.76-9" /> Additionally, 122 bombers were damaged and needed repairs before their next flights. Of 2,900 men in the crews, about 650 did not return, although some survived as [[Prisoner of war|prisoners of war]]. Only 33 bombers landed without damage. These losses were a result of concentrated attacks by over 300 German fighters.<ref name="Hess.p64" />

[[File:B-17G formation on bomb run.jpg|thumb|B-17Gs of the 384th Bomb Group on a bomb run, 1944]]

Such high losses of aircrews could not be sustained, and the USAAF, recognizing the vulnerability of heavy bombers to interceptors when operating alone, 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. At the same time, the German nightfighting ability noticeably improved to counter the nighttime strikes, challenging the conventional faith in the cover of darkness.<ref name="Weigley.341" /> The 8th Air Force alone lost 176 bombers in October 1943,<ref name="Hess.p67" /> and was to suffer similar casualties on {{Nowrap|11 January}} 1944 on missions to [[Oschersleben]], [[Halberstadt]], and [[Braunschweig|Brunswick]]. [[Lieutenant general (United States)|Lieutenant General]] [[Jimmy Doolittle|James Doolittle]], commander of the 8th, had ordered the second Schweinfurt 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, and as a result, 60 B-17s were destroyed.<ref name="Hess.69-71" /><ref name="C&W.151" />

A third raid on Schweinfurt on {{Nowrap|24 February}} 1944 highlighted what came to be known as "[[Big Week]]",<ref name="Weigley.340-1" /> during which the bombing missions were directed against German aircraft production.<ref name="Weigley.341" /> German fighters needed to respond, and the [[North American P-51 Mustang]] and [[Republic P-47 Thunderbolt]] fighters (equipped with improved [[drop tank]]s to extend their range) accompanying the American heavies all the way to and from the targets engaged them.<ref name="Weigley.342" /> The escort fighters reduced the loss rate to below 7%, with a total of 247 B-17s lost in 3,500 [[sortie]]s while taking part in the Big Week raids.<ref name="C&W.162" />

By September 1944, 27 of the 42 bomb groups of the 8th Air Force and six of the 21 groups of the [[15th Expeditionary Mobility Task Force|15th Air Force]] used B-17s. Losses to [[flak]] continued to take a high toll of heavy bombers through 1944, but the war in Europe was being won by the Allies. And by {{Nowrap|27 April}} 1945, 2 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.<ref name="USAAF.04-45" />

=== Pacific Theater ===
[[File:NARA 28-1277a.jpg|thumb| B-17C AAF S/N ''40-2074'' at [[Hickam Field]]: An onboard fire burnt the aircraft in two shortly after landing on {{Nowrap|7 December}} 1941. One crewman was killed by a Zero attack.<ref name="A&K.1" />]]

On 7 December 1941, a group of 12 B-17s of the 38th (four B-17C) and 88th (eight B-17E) Reconnaissance Squadrons, en route to reinforce the Philippines, was flown into Pearl Harbor from [[Hamilton Field, California]], arriving while the surprise [[attack on Pearl Harbor]] was going on. Leonard "Smitty" Smith Humiston, co-pilot on [[First Lieutenant]] Robert H. Richards' B-17C, AAF S/N ''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 member who suffered an abrasion on his hand. Japanese activity forced them to divert from [[Hickam Field]] to [[Bellows Field]]. On landing, the aircraft overran the runway and ran into a ditch, where it was then strafed. Although initially deemed repairable, ''40-2049'' (11th BG / 38th RS) received more than 200 bullet holes and never flew again. Ten of the 12 Fortresses survived the attack.<ref name="A&K.2" />

By 1941, the [[Far East Air Force (United States)|Far East Air Force]] (FEAF) based at [[Clark Air Base|Clark Field]] in the Philippines had 35 B-17s, with the War Department eventually planning to raise that to 165.<ref name="bloody p55-6" /> 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 airfields in [[Taiwan|Formosa]], in accordance with [[Rainbow 5]] war plan directives, but this was overruled by General Douglas MacArthur.<ref name="Bloody p163" /> A series of [[Battle of the Philippines (1941–42)#Far East Air Force controversy|disputed discussions and decisions]], followed by several confusing and false reports of air attacks, delayed the authorization of the sortie. By the time the B-17s and escorting [[Curtiss P-40 Warhawk]] fighters were about to get airborne, they were destroyed by Japanese bombers of the [[11th Air Fleet (Imperial Japanese Navy)|11th Air Fleet]]. The FEAF lost half its aircraft during the first strike,<ref name="Bloody p166-7" /> and was all but destroyed over the next few days.{{citation needed|date=October 2017}}

Another early World War II Pacific engagement, on {{Nowrap|10 December}} 1941, involved [[Colin Kelly]], who reportedly crashed his B-17 into the [[Japanese battleship Haruna|Japanese battleship ''Haruna'']], which was later acknowledged as a near bomb miss on the [[Japanese cruiser Ashigara|heavy cruiser ''Ashigara'']]. Nonetheless, this deed made him a celebrated [[war hero]]. Kelly's B-17C AAF S/N ''40-2045'' (19th BG / 30th BS) crashed about {{convert|6|mi|km|sigfig=1|abbr=on}} 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 (United States)|Distinguished Service Cross]].<ref name="Sal.p64" />
Noted Japanese ace [[Saburō Sakai]] is credited with this kill, and in the process, came to respect the ability of the Fortress to absorb punishment.<ref name="Sakai" />

[[File:Typhoon McGoon II, New Caledonia, January 1943.jpg|left|thumb|B-17E BO AAF S/N ''41-9211'' <br /> ''Typhoon McGoon II'' of the 11th BG / 98th BS, taken in January 1943 in New Caledonia: The antennas mounted upon the nose were used for radar tracking surface vessels.]]

B-17s were used in early battles of the Pacific with little success, notably the [[Battle of Coral Sea]]<ref name="WoF p96" /> and [[Battle of Midway]].<ref name="Sword p180,329" /> 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 they soon found only 1% of their bombs hit targets. However, B-17s were operating at heights too great for most [[A6M Zero]] fighters to reach.

The B-17's greatest success in the Pacific was in the [[Battle of the Bismarck Sea]], in which aircraft of this type were responsible for damaging and sinking several Japanese transport ships. On 2 March 1943, six B-17s of the 64th Squadron flying at {{convert|10000|ft|m|sigfig=1|abbr=on}} attacked a major Japanese troop convoy off [[New Guinea]], using [[skip bombing]] to sink {{ship|SS|Kyokusei Maru||2}}, which carried 1,200 army troops, and damage two other transports, ''Teiyo Maru'' and ''Nojima''. On 3 March 1943, 13 B-17s flying at {{convert|7000|ft|m|sigfig=1|abbr=on}} bombed the convoy, forcing the convoy to disperse and reducing the concentration of their anti-aircraft defenses. The B-17s attracted a number of [[Mitsubishi A6M Zero]] fighters, which were in turn attacked by the P-38 Lightning escorts. One B-17 broke up in the air, and its crew was forced to take to their parachutes. Japanese fighter pilots machine-gunned some of the B-17 crew members as they descended and attacked others in the water after they landed.<ref name="Gillison, pp. 692-693">[[#Gillison|Gillison]], pp. 692–93</ref> Five of the Japanese fighters strafing the B-17 aircrew were promptly engaged and shot down by three Lightnings, though these were also then lost.<ref name="historynet">{{cite journal |url=http://www.historynet.com/battle-of-the-bismarck-sea.htm |title=Battle of the Bismarck Sea |first=Lawrence |last=Spinetta |date=November 2007 |journal=World War II |issn=0898-4204|access-date=2 August 2013}}</ref> The allied fighter pilots claimed 15 Zeros destroyed, while the B-17 crews claimed five more.<ref name="Gillison, pp. 692-693"/><ref name="Watson, pp. 144-145">[[#Watson|Watson]], pp. 144–45</ref> Actual Japanese fighter losses for the day were seven destroyed and three damaged.<ref name="Gamble 2010 313">[[#Gamble|Gamble]], pp. 313</ref><ref name="awm" /> The remaining seven transports and three of the eight destroyers were then sunk by a combination of low level strafing runs by [[Royal Australian Air Force]] [[Bristol Beaufighter|Beaufighters]], and skip bombing by USAAF [[North American B-25 Mitchell]]s at {{convert|100|ft|m|abbr=on}}, while B-17s claimed five hits from higher altitudes.<ref name="Frisbee" /> On the morning of 4 March 1943, a B-17 sank the destroyer ''Asashio'' with a {{convert|500|lb|kg|abbr=on}} bomb while she was picking up survivors from ''Arashio''.<ref>{{harvnb|Morison|1950|p=61}}</ref>

At their peak, 168 B-17 bombers were in the Pacific theater in September 1942, but already in mid-1942 Gen. Arnold had decided that the B-17 was unsuitable for the kind of operations required in the Pacific and made plans to replace all of the B-17s in the theater with B-24s (and later, B-29s) as soon as they became available. Although the conversion was not complete until mid-1943, B-17 combat operations in the Pacific theater came to an end after a little over a year.<ref>Kenney, George C. ''General Kenney Reports''. New York: Duall, Sloan and Pearce, 1949.</ref> Surviving aircraft were reassigned to the 54th Troop Carrier Wing's special airdrop section and were used to drop supplies to ground forces operating in close contact with the enemy. Special airdrop B-17s supported Australian commandos operating near the Japanese stronghold at Rabaul, which had been the primary B-17 target in 1942 and early 1943.<ref>Jacobson 1945 {{page needed|date=January 2012}}</ref>

B-17s were still used in the Pacific later in the war, however, mainly in the [[combat search and rescue]] role. A number of B-17Gs, redesignated B-17Hs and later SB-17Gs, were used in the Pacific during the final year of the war to carry and drop lifeboats to stranded bomber crews who had been shot down or crashed at sea.<ref>{{Cite web|url=http://www.pbyrescue.com/Aircraft/b-17h.htm|title=The B-17H "Flying Dutchman"|website=www.pbyrescue.com|access-date=24 March 2017|archive-url=https://web.archive.org/web/20170420225027/http://www.pbyrescue.com/Aircraft/b-17h.htm|archive-date=20 April 2017|url-status=dead}}</ref> These aircraft were nicknamed [[Dumbo (air-sea rescue)|Dumbos]], and remained in service for many years after the end of World War II.<ref>[[A-1 lifeboat]]</ref>
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=== Bomber defense ===
[[File:B-17 Schweinfurt.jpg|thumb|Formation flying through dense [[flak]] over [[Merseburg]], Germany]]
Before the advent of long-range [[Fighter aircraft|fighter]] escorts, B-17s had only their [[.50 BMG|.50 caliber]] [[M2 Browning machine gun]]s 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.<ref name="Boeing" /> Defensive armament increased from four {{convert|0.50|in|mm|sigfig=3|abbr=on}} machine guns and one {{convert|0.30|in|mm|sigfig=3|abbr=on}} nose machine gun in the B-17C, to thirteen {{convert|0.50|in|mm|sigfig=3|abbr=on}} machine guns in the B-17G. But because the bombers could not [[air combat manoeuvring|maneuver]] when attacked by fighters and needed to be flown straight and level during their final bomb run, individual aircraft struggled to fend off a direct attack.

A 1943 survey by the [[USAAF]] found that over half the bombers shot down by the Germans had left the protection of the main formation.<ref name="B-17.de 2" /> To address this problem, the United States developed the bomb-group formation, which evolved into the staggered [[combat box]] formation in which all the B-17s could safely cover any others in their formation with their machine guns. This made a formation of bombers a dangerous target to engage by enemy fighters.<ref name="Manual 2" /> In order to more quickly form these formations, [[assembly ship]]s, planes with distinctive paint schemes, were utilized to guide bombers into formation, saving assembly time.<ref name="MAH">{{cite web |title=Why Use Colourful Camouflage in World War 2? – Assembly Ships |url=https://www.youtube.com/watch?v=WYm1QEV69bo | archive-url=https://ghostarchive.org/varchive/youtube/20211123/WYm1QEV69bo| archive-date=2021-11-23 | url-status=live|website=Youtube | date=6 September 2018 |publisher=Military Aviation History}}{{cbignore}}</ref><ref name="Polka Dot">{{cite web |title=Polka Dot Warriors > Vintage Wings of Canada |url=http://www.vintagewings.ca/VintageNews/Stories/tabid/116/articleType/ArticleView/articleId/477/language/en-CA/Polka-Dot-Warriors.aspx |website=www.vintagewings.ca |publisher=Vintage Wings |access-date=7 February 2019 |archive-date=1 December 2019 |archive-url=https://web.archive.org/web/20191201121322/http://www.vintagewings.ca/VintageNews/Stories/tabid/116/articleType/ArticleView/articleId/477/language/en-CA/Polka-Dot-Warriors.aspx |url-status=dead }}</ref>  ''Luftwaffe'' fighter pilots likened attacking a B-17 combat box formation to encountering a ''fliegendes Stachelschwein'', "flying porcupine", with dozens of machine guns in a combat box aimed at them from almost every direction. However, the use of this rigid formation meant that individual aircraft could not engage in evasive maneuvers: they had to fly constantly in a straight line, which made them vulnerable to German flak. Moreover, German fighter aircraft later developed the tactic of high-speed strafing passes rather than engaging with individual aircraft to inflict damage with minimum risk.{{citation needed|date=October 2017}}

The B-17 was noted for its ability to absorb battle damage, still reach its target and bring its crew home safely.<ref name="Manual" /><ref name="browne" /><ref name="Johnsen 2006" /> Wally Hoffman, a B-17 pilot with the Eighth Air Force during World War&nbsp;II, said, "The plane can be cut and slashed almost to pieces by enemy fire and bring its crew home."<ref name="Hoffman" /> [[Martin Caidin]] reported one instance in which a B-17 suffered a midair collision with a [[Focke-Wulf Fw 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 B-17 was reported as shot down by observers, but it survived and brought its crew home without injury.<ref name="Caidin.p86" /> Its toughness was compensation for its shorter range and lighter bomb load compared to the B-24 and British Avro Lancaster heavy bombers.{{Clarify|is this statement backed by the ref for the following sentence?|date=June 2010}} Stories circulated of B-17s returning to base with tails shredded, engines destroyed and large portions of their wings destroyed by flak.<ref name="DurableB-17Colorado" /> This durability, together with the large operational numbers in the Eighth Air Force and the fame achieved by the ''[[Memphis Belle (B-17)|Memphis Belle]]'', made the B-17 a key bomber aircraft of the war. Other factors such as combat effectiveness and political issues also contributed to the B-17's success.<ref name="B17vB24" />

The B-17 adopted early [[electronic countermeasure]]s, such as [[chaff (countermeasure)|Window]] and [[Carpet (jammer)|Carpet]] to confuse German radar. This greatly reduced the effectiveness of German Flak, by perhaps as much as 75%, meaning that 450 bombers were saved by these technologies.<ref>{{cite thesis|page=30|url=https://apps.dtic.mil/sti/citations/ADA265494|title=The Radar Eye Blinded: The USAF and Electronic Warfare, 1945-1955| last=Kuehl |first= Daniel T.|year=1992}}</ref>

=== Luftwaffe attacks ===
[[File:B-17 Damage Cologne.jpg|thumb|B-17G ''43-38172'' of the 8th AF 398th BG 601st BS which was damaged on a bombing mission over [[Cologne]], Germany, on {{Nowrap|15 October}} 1944; the bombardier was killed.<ref>[http://www.398th.org/Images/Images_Aircraft_B-17/Aircraft/43-38172-3O-P_19441015_JBk.html "43-38172"]. ''398th.org''. Retrieved: 24 January 2012.</ref>]]
After examining wrecked B-17s and B-24s, Luftwaffe officers discovered that on average it took about 20 hits with [[MG 151 cannon|20 mm]] shells fired from the rear to bring them down.<ref name="AFM.76-9" /> 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 fire one thousand {{convert|20|mm|in|abbr=on}} rounds at a bomber.<ref name="AFM.76-9" /> Early versions of the Fw 190, one of the best German interceptor fighters, were equipped with two {{convert|20|mm|in|abbr=on}} [[MG FF cannon|MG FF]] cannons, which carried only 500 rounds when belt-fed (normally using 60-round [[drum magazine]]s in earlier installations), and later with the better Mauser MG 151/20 cannons, which had a longer effective range than the MG FF weapon. Later versions carried four or even six MG 151/20 cannon and twin [[MG 131 machine gun|13&nbsp;mm machine guns]]. The German fighters found that when attacking from the front, where fewer defensive guns were mounted (and where the pilot was exposed and not protected by armor as he was from the rear), it took only four or five hits to bring a bomber down.<ref name="AFM.76-9" />

To rectify the Fw 190's shortcomings, the number of cannons fitted was doubled to four, with a corresponding increase in the amount of ammunition carried, creating [[Focke-Wulf Fw 190 operational history#The Sturmböcke|the ''Sturmbock'']] bomber destroyer version. This type replaced the vulnerable twin-engine ''Zerstörer'' heavy fighters which could not survive interception by P-51 Mustangs flying well ahead of the combat boxes in an [[air supremacy]] role starting very early in 1944 to clear any Luftwaffe defensive fighters from the skies. By 1944, a further upgrade to [[Rheinmetall]]-[[Borsig]]'s {{convert|30|mm|in|abbr=on}} [[MK 108 cannon]]s mounted either in the wing, or in underwing, conformal mount gun pods, was made for the ''Sturmbock'' Focke-Wulfs as either the [[Rüstsatz|/R2 or /R8 field modification kits]], enabling aircraft to bring a bomber down with just a few hits.<ref name="AFM.76-9" />

The adoption of the [[21 cm Nebelwerfer 42|21 cm Nebelwerfer]]-derived ''[[Werfer-Granate 21]]'' (Wfr. Gr. 21) rocket mortar by the Luftwaffe in mid-August 1943 promised the introduction of a major "stand-off" style of offensive weapon&nbsp;– one strut-mounted tubular launcher was fixed under each wing panel on the Luftwaffe's single-engine fighters, and two under each wing panel of a few twin-engine [[Messerschmitt Bf 110|Bf 110]] daylight ''Zerstörer'' aircraft.<ref name="AFM.76-9" /> However, due to the slow 715&nbsp;mph velocity and characteristic [[Bullet drop|ballistic drop]] of the fired rocket (despite the usual mounting of the launcher at about 15° upward orientation), and the small number of fighters fitted with the weapons, the Wfr. Gr. 21 never had a major effect on the combat box formations of Fortresses.<ref name="AFM.76-9" /> The Luftwaffe also fitted heavy-caliber ''Bordkanone''-series 37, 50 and even {{convert|75|mm|in|sigfig=3|abbr=on}} cannon as anti-bomber weapons on twin-engine aircraft such as the special [[Junkers Ju 88|Ju 88P]] fighters, as well as one model of the [[Messerschmitt Me 410|Me 410]] ''Hornisse'' but these measures did not have much effect on the American strategic bomber offensive. The [[Messerschmitt Me 262|Me 262]], however, had moderate success against the B-17 late in the war. With its usual nose-mounted armament of four [[MK 108 cannon]]s, and with some examples later equipped with the [[R4M rocket]], launched from underwing racks, it could fire from outside the range of the bombers' {{convert|.50|in|mm|sigfig=3|abbr=on}} defensive guns and bring an aircraft down with one hit,<ref name="Schollars" /> as both the MK 108's shells and the R4M's warheads were filled with the "shattering" force of the strongly [[Brisance|brisant]] [[RDX|Hexogen]] military explosive.

=== Luftwaffe-captured B-17s ===
[[File:B17 kg200.jpg|thumb|Captured B-17F-27-BO in ''[[Luftwaffe]]'' markings, the USAAF-named "Wulfe-Hound", ''41-24585'', of the 360th BS/303rd BG, was downed on 12 December 1942 near [[Leeuwarden]], [[Netherlands]], while on a raid on [[Rouen]], [[France]]. The first Flying Fortress to fall intact into German hands, it was operated by [[Kampfgeschwader 200|''Kampfgeschwader'' 200]] from March 1944.<ref>Thomas, Geoffrey J., and Ketley, Barry, "KG 200 – The Luftwaffe's Most Secret Unit", Hikoku Publications Ltd., Crowborough, East Sussex, UK, 2003, {{ISBN|1-902109-33-3}}, pp. 57–58, 66.</ref>]]

During World War II approximately 40 B-17s were captured and refurbished by Germany after crash-landing or being forced down, with about a dozen put back into the air. Given German ''[[Balkenkreuz]]'' national markings on their wings and fuselage sides, and [[swastika]] tail fin–flashes, the captured B-17s were used to determine the B-17's vulnerabilities and to train German interceptor pilots in attack tactics.<ref name="WoF p89" /> Others, with the cover designations Dornier Do 200 and Do 288, were used as long-range transports by the [[Kampfgeschwader 200|''Kampfgeschwader'' 200]] special duties unit, carrying out agent drops and supplying secret airstrips in the Middle East and North Africa. They were chosen specifically for these missions as being more suitable for this role than other available German aircraft; they never attempted to deceive the Allies and always wore full ''Luftwaffe'' markings.<ref name="Donald Am p23" /><ref name="Wixley p30" /> One B-17 of KG200, bearing the ''Luftwaffe''{{'}}s KG 200 ''Geschwaderkennung'' (combat wing code) markings ''A3+FB'', was interned by Spain when it landed at [[Valencia]] airfield, {{Nowrap|27 June}} 1944, remaining there for the rest of the war.<ref name="Northstar" /> It has been alleged that some B-17s kept their Allied markings and were used by the ''Luftwaffe'' in attempts to infiltrate B-17 bombing formations and report on their positions and altitudes.<ref>{{Cite book|title=Aluminum Castles: WWII from a gunner's view|last=Richardson|first=Wilbur|publisher=Cantemos|date=26 May 2012|pages=29–30|quote=We also reported seeing a B17 flying at a safe distance from the formation. This mystery fortress shadowed the formation inbound from the Rhine river and we were informed others had seen it back across Belgium on the way out. A fortress manned by the enemy created an unsettling feeling in all of us.}}</ref> According to these allegations, the practice was initially successful, but Army Air Forces 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.<ref name="Northstar" />

=== Soviet-interned B-17s ===
The U.S. did not offer B-17s to the Soviet Union as part of its [[Lend-Lease|war materiel assistance program]], but at least 73 aircraft were acquired by the [[Soviet Air Force]]. These aircraft had landed with mechanical trouble during the [[Operation Frantic|shuttle bombing raids]] over Germany or had been damaged by a ''Luftwaffe'' raid in [[Poltava]]. The Soviets restored 23 to flying condition and concentrated them in the 890th Bomber Regiment of the [[45th Bomber Aviation Division]],<ref>{{cite web|last=Holm |first=Michael |title=890th Bryanskiy Bomber Aviation Regiment|url=https://www.ww2.dk/new/air%20force/regiment/bap/890bap.htm}}</ref> but they never saw combat. In 1946 (or 1947, according to Holm), the regiment was assigned to the [[Kazan]] factory (moving from [[Baranovichi]]) to help the Soviet effort to reproduce the more advanced [[Boeing B-29 Superfortress|Boeing B-29]] as the [[Tupolev Tu-4]].<ref name="Gordon p. 479">Gordon 2008, p. 479.</ref>

=== Swiss-interned B-17s ===
During the [[Strategic bombing during World War II|Allied bomber offensive]], some US and British bombers landed in Switzerland and were [[internment|interned]]. Some had been damaged and were unable to get back to Allied bases. Others flew into Swiss airspace due to navigation errors, and on rare occasions, [[Aerial incidents in Switzerland in World War II|accidentally bombed Swiss cities]]. Swiss fighter aircraft intercepted such aircraft and sought to force them to land.

In October 1943, a B-17F-25-VE (tail number 25841) developed engine trouble after a raid over Germany and was forced to land in Switzerland. The plane and its US flight crew were interned. The aircraft was turned over to the [[Swiss Air Force]], which flew the bomber until the end of the war, using other interned but non-airworthy B-17s for spare parts. The bomber's topside surfaces were repainted a dark [[olive drab]], but it retained its light gray underwing and lower fuselage surfaces. It carried the Swiss national white cross insignia in red squares on the topside and underside of its wings, and on both sides of its rudder and its fuselage, with the light gray flash letters "RD" and "I" on either side of the fuselage insignias.<ref name="Cravens, Wesley 1956">Cravens, Wesley. ''Army Air Forces in World War II''. Washington, D.C.: Office of Air Force History, 1956.</ref>

=== Japanese-captured B-17s ===
[[File:B17jp.jpg|thumb|This captured USAAF Boeing B-17D, in Japanese livery, was flown to Japan for technical evaluation]]

In 1942, Japanese technicians and mechanics rebuilt three damaged B-17s, one "D" and two "E" series, using parts salvaged from abandoned B-17 wrecks in the Philippines and the Java East Indies.<ref>{{cite web| url = https://www.historynet.com/japans-fleet-flying-forts.htm| title = The Surprising Story of Japan's B-17 Fleet| date = 26 January 2018}}</ref> The three bombers, which still contained their top-secret [[Norden bombsight]]s, were [[Ferry flying|ferried]] to Japan where they underwent extensive technical evaluation by the ''Giken'', the [[Imperial Japanese Army Air Force]]'s Air Technical Research Institute (''Koku Gijutsu Kenkyujo'') at Tachikawa's air field. The "D" model, later deemed an obsolescent design, was used in Japanese training and propaganda films. The two "E"s were used to develop air combat tactics for use against B-17s; they were also used as enemy aircraft in pilot and crew training films. One of the two "E"s was photographed late in the war by US aerial recon. It was code-named "Tachikawa 105" after the mystery aircraft's wingspan ({{cvt|104|ft}}) but not correctly identified as a captured B-17 until after the war. No traces of the three captured Flying Fortresses were ever found in Japan by [[Allies of World War II|Allied]] occupation forces. The bombers were assumed either lost by various means or scrapped late in the war for their vital war materials.<ref name="Bowers Boeing p314" />

=== Postwar history ===
==== U.S. Air Force ====
{{See also|3205th Drone Group}}
[[File:QB-17 Flying Fortress Drones over New Mexico 1946.jpg|thumb|left|BQ-17 Flying Fortress drones over New Mexico, April 1946]]

After World War II, the B-17 was quickly phased out of use as a bomber and the Army Air Forces retired most of its fleet. Flight crews ferried the bombers back across the Atlantic to the United States where the majority were sold for scrap and melted down, although many remained in use in second-line roles such as VIP transports, air-sea rescue and photo-reconnaissance.<ref name="Swan mil p80" /><ref name="Bowers Boeing p290" /> [[Strategic Air Command]] (SAC), established in 1946, used reconnaissance B-17s (at first called F-9 [''F'' for ''Fotorecon''], later RB-17) until 1949.<ref name="Bowers Boeing p310-1" /><ref name="Knaack bomber p465" />

The USAF [[Air Rescue Service]] of the [[Military Air Transport Service]] (MATS) operated B-17s as so-called "Dumbo" [[air-sea rescue]] aircraft. Work on using B-17s to carry [[airborne lifeboat]]s had begun in 1943, but they entered service in the European theater only in February 1945. They were also used to provide search and rescue support for [[Boeing B-29 Superfortress|B-29]] raids against Japan. About 130 B-17s were converted to the air-sea rescue role, at first designated B-17H and later SB-17G. Some SB-17s had their defensive guns removed, while others retained their guns to allow use close to combat areas. The SB-17 served through the [[Korean War]], remaining in service with USAF until the mid-1950s.<ref name="Bowers Boeing p303-4" /><ref>Hess & Winchester 1997, pp. 86, 89–90</ref>

In 1946, surplus B-17s were chosen as [[Unmanned aerial vehicle|drone aircraft]] for atmospheric sampling during the [[Operation Crossroads]] atomic bomb tests, being able to fly close to or even through the [[mushroom cloud]]s without endangering a crew. This led to more widespread conversion of B-17s as drones and drone control aircraft, both for further use in atomic testing and as targets for testing [[surface-to-air missile|surface-to-air]] and [[air-to-air missile]]s.<ref name="WoF p91" /> {{nowrap|One hundred and seven B-17s}} were converted to drones.<ref name="Flight Sperry" /> The last operational mission flown by a USAF Fortress was conducted on {{Nowrap|6 August}} 1959, when a DB-17P, serial'' 44-83684 '', directed a QB-17G, out of [[Holloman Air Force Base]], New Mexico, as a target for an [[AIM-4 Falcon]] air-to-air missile fired from a [[McDonnell F-101 Voodoo]]. A retirement ceremony was held several days later at Holloman AFB, after which ''44-83684'' was retired.{{Citation needed|date=October 2010}} It was subsequently used in various films and in the 1960s television show ''[[Twelve O'Clock High (TV series)|12 O'Clock High]]'' before being retired to the [[Planes of Fame]] aviation museum in Chino, California.<ref>{{cite web |url = http://warbirdregistry.org/b17registry/b17-4483684.html |title = Warbird Registry – Boeing B-17 Flying Fortress |website = warbirdregistry.org }}</ref> Perhaps the most famous B-17, the ''[[Memphis Belle (aircraft)|Memphis Belle]]'', has been restored – with the B-17D ''[[The Swoose]]'' under way – to her World War II wartime appearance by the [[National Museum of the United States Air Force]] at [[Wright-Patterson Air Force Base]], Ohio.<ref name="NMAF Memphis" />

==== U.S. Navy and Coast Guard ====
[[File:US Navy PB-1W.jpg|thumb|Under project '''Cadillac&nbsp;II''', an AN/APS-20 radar was fitted onto the B-17G, making the PB-1W one of the first [[Airborne early warning]] aircraft.]]

During the last year of World War II and shortly thereafter, the [[United States Navy]] (USN) acquired 48 ex-USAAF B-17s for patrol and air-sea rescue work. The first two ex-USAAF B-17s, a B-17F (later modified to B-17G standard) and a B-17G were obtained by the Navy for various development programs.<ref name="Bowers Boeing p310-1" /> At first, these aircraft operated under their original USAAF designations, but on 31 July 1945 they were assigned the naval aircraft designation PB-1, a designation which had originally been used in 1925 for the [[Boeing Model 50]] experimental flying boat.<ref name="Swan Navy" />

Thirty-two B-17Gs<ref name="DABASv2 p661" /> were used by the Navy under the designation PB-1W, the suffix -W indicating an airborne early warning role. A large radome for an [[S-band]] [[AN/APS-20]] search radar was fitted underneath the fuselage and additional internal fuel tanks were added for longer range, with the provision for additional underwing fuel tanks. Originally, the B-17 was also chosen because of its heavy defensive armament, but this was later removed. These aircraft were painted dark blue, the standard Navy paint scheme which had been adopted in late 1944.<ref name="Bowers Boeing p310-1" /><ref name="Swan Navy" /> PB-1Ws continued in USN service until 1955, gradually being phased out in favor of the Lockheed WV-2 (known in the USAF as the [[EC-121]], a designation [[1962 United States Tri-Service aircraft designation system|adopted by the USN in 1962]]), a military version of the [[Lockheed Constellation|Lockheed 1049 Constellation]] commercial airliner.{{Citation needed|date=October 2017}}

In July 1945, 16 B-17s were transferred to the Coast Guard via the Navy; these aircraft were initially assigned U.S. Navy Bureau Numbers (BuNo), but were delivered to the Coast Guard designated as PB-1Gs beginning in July 1946.<ref name="Bowers Boeing p310-1" /><ref name="WoF p89-0" /> Coast Guard PB-1Gs were stationed at a number of bases in the U.S. and Newfoundland, with five at [[Coast Guard Air Station Elizabeth City]], North Carolina, two at [[San Francisco International Airport|CGAS San Francisco]], two at [[NAS Argentia]], Newfoundland, one at [[CGAS Kodiak]], Alaska, and one in Washington state.<ref name="WoF p89-0" /> They were used primarily in the "Dumbo" air-sea rescue role, but were also used for [[International Ice Patrol|iceberg patrol]] duties and for photo mapping. The Coast Guard PB-1Gs served throughout the 1950s, the last example not being withdrawn from service until 14 October 1959.<ref name="Bowers Boeing p310-1" /><ref name="USCG" />

=== Special operations ===
B-17s were used by the CIA front companies Civil Air Transport, Air America and Intermountain Aviation for special missions. These included B-17G ''44-85531'', registered as N809Z. These aircraft were primarily used for agent drop missions over the People's Republic of China, flying from Taiwan, with Taiwanese crews. Four B-17s were shot down in these operations.<ref>Pocock, Chris. ''The Black Bats: CIA Spy Flights Over China From Taiwan, 1951–1969''. Atglen, Pennsylvania: Schiffer Military History, 2010. {{ISBN|978-0-7643-3513-6}}.</ref>{{page needed |date=February 2024}}

In 1957 the surviving B-17s had been stripped of all weapons and painted black. One of these Taiwan-based B-17s was flown to [[Clark Air Base]] in the Philippines in mid-September, assigned for covert missions into Tibet.

On 28 May 1962, N809Z, piloted by Connie Seigrist and Douglas Price, flew Major James Smith, USAF and Lieutenant Leonard A. LeSchack, USNR to the abandoned Soviet arctic ice station NP 8, as [[Operation Coldfeet]]. Smith and LeSchack parachuted from the B-17 and searched the station for several days. On 1 June, Seigrist and Price returned and picked up Smith and LeSchack using a [[Fulton Skyhook]] system installed on the B-17.<ref>{{cite web |url=http://www.utdallas.edu/library/collections/speccoll/Leeker/b17.pdf |title=The Boeing B-17s |archive-url=https://web.archive.org/web/20100928084808/http://www.utdallas.edu/library/collections/speccoll/Leeker/b17.pdf |archive-date=28 September 2010 |website=utdallas.edu |accessdate= 25 July 2011}}</ref> N809Z was used to perform a Skyhook pick up in the James Bond movie ''[[Thunderball (film)|Thunderball]]'' in 1965. This aircraft, now restored to its original B-17G configuration, was on display in the [[Evergreen Aviation & Space Museum]] in [[McMinnville, Oregon]] until it was sold to the [[Collings Foundation]] in 2015.<ref>{{Cite web|url=https://www.collingsfoundation.org/2015/12/b-17-flying-fortress-to-join-cf/|title = B-17 Flying Fortress to join CF |publisher=the Collings Foundation |date=2015}}</ref>