Big Week Between February 20 – 25 , 1944 , as part of the European strategic bombing campaign , the United States Strategic Air Forces ( USSTAF ) launched Operation Argument , a series of missions against the Third Reich that became known as Big Week . The planners intended to lure the Luftwaffe into a decisive battle by launching massive attacks on the German aircraft industry . By defeating the Luftwaffe , the Allies would achieve air superiority and the invasion of Europe could proceed . The daylight bombing campaign was also supported by RAF Bomber Command , operating against the same targets at night . Arthur Harris resisted contributing RAF forces as it diverted them from the British area bombing offensive . It took a direct order from Air Chief Marshal Sir Charles Portal , Chief of the Air Staff to force Harris to comply . RAF Fighter Command also provided escort for USAAF bomber formations , just at the time that the Eighth Air Force had started introducing the P - 51 long - range fighter to take over the role . Background . Prior to the Big Week , throughout 1943 , the U . S . 8th Air Force had been growing in size and experience , and started pressing attacks deeper into Germany . It was believed that the defensive firepower of the B - 17 and B - 24 bombers , typically ten . 50 caliber machine guns or more , would allow them to defend themselves as long as they remained arranged into tight formations , allowing for overlapping fire . In practice this proved less successful ; although the bombers did claim a fair number of German fighters , losses among the bombers were unsustainable . The Schweinfurt - Regensburg mission s are a famous example . On August 17 , 1943 , 230 bombers launched a mission against the ball bearing factories in Schweinfurt and another 146 against the aircraft factories in Regensburg . Of this force , 60 aircraft were lost before returning to base , and another 87 had to be scrapped due to irreparable damage . The Germans claimed 27 fighters lost , serious enough , but paling in comparison to the losses on the part of the US forces . A second raid on October 14 , 1943 , infamously remembered as " Black Thursday " fared almost as poorly ; of the 291 aircraft on the mission , 77 were lost . Daylight missions into Germany were called off in order to rebuild the forces . The raids were extensively studied by both forces . The Germans concluded that their current strategy of deploying twin - engine heavy fighter designs with heavy armament to make them usable as bomber destroyer s , serving primarily with the " Zerstörergeschwader " combat wings was working well . Over the winter of 1943 / 44 they continued this program , adding to their heavy fighter ranks and developing heavier armaments for all of their aircraft . They also pulled almost all of their fighter forces back into Germany , as the majority of their losses were due to fighter actions over forward areas . There seemed to be no point to try attacking the bombers with enemy fighters in the area . The Allied forces came to other conclusions . Schweinfurt demonstrated that the bombers were not able to protect themselves , contrary to earlier thinking , and fighter cover had to be extended over the entire mission . Luckily for the U . S . , the P - 51 Mustang was just starting to arrive in quantity , an aircraft that had the range to escort the bombers to targets deep within Germany . Over the winter they re - organized their fighter squadrons as Mustangs arrived and longer - range versions of their existing aircraft were developed . By the time the winter weather started to clear in early 1944 , both forces had implemented their plans and were waiting to put them into action . The U . S . , expecting a fighter advantage , planned missions that would demand a German response . They decided to make massive raids on the German fighter factories ; if the Germans chose not to respond they would be at risk of losing the air war without firing a shot , if they did respond , they would meet fighters in the process . But the Germans needed no provocation , they were ready to meet any future raid with their newly prepared forces . But by up - gunning their fighters they reduced their performance , making them easy targets for the new and unexpected Mustangs . Operations . The Americans flew heavily escorted missions against airframe manufacturing and assembly plants and other targets in numerous German cities including : Leipzig , Brunswick , Gotha , Regensburg , Schweinfurt , Augsburg , Stuttgart and Steyr . In six days , the Eighth Air Force bombers based in England flew more than 3 , 000 sorties and the Fifteenth Air Force based in Italy more than 500 . Together they dropped roughly 10 , 000 tons of bombs . During Big Week the Eighth Air Force lost 97 B - 17s , 40 B - 24s , and another 20 scrapped due to damage . The Fifteenth Air Force lost 90 aircraft and American fighter losses stood at 28 . Although these numbers are high in absolute terms , the numbers of bombers involved in the missions were much higher than previously , and the losses represented a much smaller percentage of the attacking force . The earlier Schweinfurt missions cost the force just under 30 % of their aircraft ; for the Big Week it was under 7 % . U . S . aircrews claimed more than 500 German fighters destroyed , though the numbers were massively exaggerated . The Luftwaffe losses were high amongst their twin - engined " Zerstörer " units , and the Bf 110 and Me 410 groups were decimated . More worrying for the Jagdwaffe was the loss of 17 per - cent of its pilots — nearly 100 were killed . In contrast to the raids of the previous year , the US losses were entirely replaceable and being made good as their industrial might ramped up , while the Germans were already hard pressed due to the war in the East . Although not fatal , the Big Week was an extremely worrying development for the Germans . The actual damage to the German aircraft industry was fairly limited ; during 1944 German aircraft industry was to reach its production high , comparable with the U . S and Soviet industries . However the lack of skilled pilots due to an attritional three - front war was the factor eroding the capability of the " Jagdwaffe " . The Luftwaffe had to abandon its tactic of " maximum defensive effort " to daylight bombing missions in favor of hit - and - run intercepts . While the " Jagdwaffe " remained formidable , air superiority had passed irrevocably to the Allies . Followup . The Big Week raids demonstrated that the Luftwaffe ' s best anti - bomber weapon , twin - engine " Zerstörer " designs like the Me 410 " Hornisse " , were appallingly vulnerable against Allied fighters . They were removed from service in the west , passing the defense role primarily to the higher performance single - engine designs . Due to the effective protection offered by Allied fighters , a change of tactics was introduced : German fighters formed up well in front of the bombers , took a single head - on pass through the stream , and then departed . This gave the defending fighters little time to react , and a few shells into the cockpit area could " destroy " a bomber in one pass . In a repeat of earlier RAF strategy , the Luftwaffe also attempted to form up their own version of the " Big Wing " , which they hoped would allow them to bring the twins back into combat in the safety of a huge number of escorting single - engine designs . As had sometimes been the British experience , these formations proved extremely difficult to arrange . Big Week bolstered the confidence of U . S . strategic bombing crews . Until that time , Allied bombers avoided contact with the Luftwaffe ; now , the Americans used any method that would force the Luftwaffe into combat . Implementing this policy , the United States looked toward Berlin . Raiding the German capital , Allied leaders reasoned , would force the Luftwaffe to battle . Consequently , on March 4 , the USSTAF launched the first of several attacks against Berlin . From England 730 bombers set out with an escort of 800 fighters . Fierce battles raged and resulted in heavy losses for both sides ; 69 B - 17s were lost but the Luftwaffe lost 160 aircraft . The Allies replaced their losses ; the Luftwaffe could not . Nevertheless , the new German strategies ( using both heavily - armed Fw 190s as bomber destroyer s , and Bf 109Gs to escort them ) in the so - called " Gefechtsverband " formations were proving somewhat effective . The U . S . fighters , kept in close contact with the bombers they were protecting , could not chase down the attacking fighters before they were forced to turn around and return to the bombers . Lt . Gen . Jimmy Doolittle , commander of the 8th Air Force from the end of 1943 , responded by " freeing " the fighters , allowing them to fly far ahead of the heavy bomber formations in an air superiority " fighter sweep " mode on the outward legs , then roam far from the bomber streams and hunt down the German fighters - especially the " Sturmböcke " Focke - Wulfs , from their limited maneuverability with their heavy cannons - before they could begin to approach the bombers . Though the change was unpopular with the bomber crews , its effects were immediate and extremely effective . When the combined bomber offensive officially ended on April 1 , 1944 and control of the strategic air forces passed to U . S . General Dwight D . Eisenhower , Allied airmen were well on the way to achieving air superiority over all of Europe . While they continued strategic bombing , the AAF turned its attention to the tactical air battle in support of the Normandy invasion . RAF bomber sorties during Big Week . Bomber Command directly contributed to the attacks on the aircraft industry in Schweinfurt . Some 734 bombers were dispatched on the night of 24 / 25 February , and 695 struck the target . Of the bombs dropped , 298 hit within three miles and 22 hit inside the target area . Little damage was done . On 25 / 26 February 1944 , Bomber Command sent 600 bombers to the aircraft assembly plant at Ausberg . The attack was accurate and they destroyed some 60 percent of the industrial city . ( 2012 ) ; ISBN 978 - 0 - 425 - 25575 - 9