The Schweinfurt–Regensburg raid

On the morning of 17 August 1943 thick fog lay over the airfields of eastern England. Even so, at about eight o’clock the first of nearly four hundred Flying Fortresses of the United States Eighth Air Force began to take off. That day they were to carry out the most ambitious operation yet undertaken by American bombers in Europe: a simultaneous strike on two targets deep inside the Reich – the Messerschmitt works at Regensburg, which produced a large share of the Bf 109 fighters, and the ball-bearing factories at Schweinfurt in Franconia. At Eighth Air Force headquarters the operation was called Mission No. 84; in the literature it is known as the Schweinfurt–Regensburg raid or the “double strike”. The date was no accident: exactly a year earlier, on 17 August 1942, twelve B-17s had bombed the railway yards near Rouen in the Eighth Air Force’s first daylight raid over occupied Europe.

The anniversary, however, turned out grim. Of the 376 bombers that reached the Continent, 60 did not return – twice as many as in any previous American raid. Several dozen more were fit only for scrapping. Regensburg was hit accurately, Schweinfurt much less so, and German ball-bearing production soon returned to normal. On the same day – or rather the same night – the British bombed the rocket research centre at Peenemünde in Operation Hydra. Together the two raids came as a shock to the Luftwaffe command, and for the Americans they were a painful lesson that day bombers could not defend themselves unaided without fighter escort.

Daylight precision bombing

The American air force entered the war with a doctrine different from the British one. After painful losses in 1939–1940, RAF Bomber Command had switched to night raids and eventually to area bombing of whole cities, the most terrible example of which had come a few weeks earlier in Operation Gomorrah over Hamburg. The commander of the US Army Air Forces, General Henry H. Arnold, and his staff believed instead that heavy, well-armed bombers flying in close formation by day could fend off fighters on their own and, thanks to the Norden bombsight, hit individual factories. It would be enough, the planners thought, to destroy a few industrial “bottlenecks” to paralyse the entire German war machine.

The first months of operations from England gave no answer. Some bomb groups were sent off to North Africa, and those that remained attacked mainly U-boat bases in France, within range of British fighters. Only on 27 January 1943 did B-17s and B-24s bomb a target in Germany itself for the first time – Wilhelmshaven. Further missions to the Reich’s coast showed that the further from England, the higher the price: over Kiel on 13 June the Germans shot down 22 of the 76 bombers of one formation.

At the Casablanca Conference in January 1943 the Allies adopted a Combined Bomber Offensive: the RAF was to destroy German cities by night, the Americans selected branches of industry by day. In June, after the Trident Conference, the Pointblank directive was issued, which gave first priority to the destruction of the German fighter force – in the air, on its airfields and in its factories. Without that, neither further missions deep into the Reich nor a landing in France could be contemplated. In the spring and summer of 1943 the Eighth Air Force, commanded by General Ira Eaker, grew rapidly: instead of a handful of bomb groups it soon had more than a dozen, organised into bombardment wings. In April and July it attacked the factories producing Fw 190 fighters at Bremen, Kassel and Oschersleben.

Two targets

Production of the Luftwaffe’s other principal fighter, the Bf 109, was concentrated in two centres: the Messerschmitt works at Regensburg (with a branch at nearby Obertraubling) and Wiener Neustadt near Vienna. According to German figures, the Regensburg plants were turning out more than two thousand Bf 109s a year in 1943 and were the second-largest single-engined fighter factory in Europe. The plan, code-named Juggler, envisaged that Wiener Neustadt would be attacked by Liberators from Libya and Regensburg by B-17s from England. Weather over England repeatedly prevented take-off, so the heavy bombers from Africa – the same groups that had carried out the raid on the Ploiești refineries on 1 August – bombed Wiener Neustadt on their own on 13 August.

The second target was Schweinfurt, a small town on the Main with three large ball-bearing works: Kugelfischer (FAG), Vereinigte Kugellagerfabriken – the German subsidiary of the Swedish SKF concern – and Fichtel & Sachs. According to Allied estimates, roughly half of Germany’s rolling bearings were made there, and without them no engine, tank, aircraft or machine tool could run. For advocates of the “bottleneck” theory it was the ideal target: a few factories in a small area on which the whole armaments industry depended.

The Eighth Air Force staff combined the two tasks into one. Colonel Curtis LeMay’s bombardment wing, equipped with B-17s fitted with extra wing tanks, was to fly to Regensburg and then, instead of turning back, cross the Alps and the Mediterranean to airfields in Algeria. Close behind it, Brigadier General Robert B. Williams’s 1st Bombardment Wing was to turn north-east over Germany and strike Schweinfurt. The planners counted on the German fighters throwing themselves at the first formation, so that when they landed to refuel and rearm, the second would pass over its target almost unhindered. The escorting fighters – P-47 Thunderbolts without drop tanks – could accompany the bombers only as far as the area of Eupen on the Belgian–German border, roughly an hour’s flight from both targets. Beyond that the Fortresses would have to defend themselves.

Fog

The whole plan depended on timing the two missions together, and on 17 August that timing was lost. The Regensburg mission would last about eleven hours and had to land in Africa before dark, so the take-off window was narrow. LeMay’s wing, whose crews had practised instrument take-offs, climbed through the fog an hour and a half late. The airfields of the 1st Wing in the Midlands remained closed. The command did not call off the operation: it sent the first formation off alone and held back the second until the fog lifted and the escort fighters had returned from their first sortie and refuelled. In the end the Schweinfurt force took off more than three hours after the Regensburg force. The idea of both surprising the defences at once collapsed before the first bomb fell on Germany. The German fighters now had time to fight one battle, land, refuel and fight a second.

Regensburg

LeMay’s formation consisted of 146 B-17s from seven bomb groups, arranged in three columns. It stretched over several dozen kilometres: the last formations flew far behind the leaders and lower than them. Of the two P-47 groups that were to cover it as far as the Reich’s border, only one made the rendezvous, and it managed to cover only the head of the column; both turned back after a quarter of an hour. About fifteen minutes after crossing the Dutch coast, at roughly 10.15 a.m., the first German fighters arrived. For an hour and a half they attacked without let-up, mainly from the front, where the B-17s had their weakest defensive armament, and above all against the rear part of the formation, which had no cover. Before they broke off for lack of fuel and ammunition, they had shot down or fatally damaged at least fifteen bombers.

Over Regensburg the sky was clear and the anti-aircraft defences weak. At 11.43 a.m. British time 126 B-17s dropped about 300 tons of bombs with great precision – exceptional for the period. All six main production halls of the Messerschmitt works were destroyed or badly damaged, as were the final assembly hall and many ancillary buildings. According to German figures, nearly 400 people were killed in the works itself, while the old town and a hospital a few hundred metres from the factory survived.

The Fortresses then turned south towards the Alps. The Germans had not expected such a manoeuvre, and most of their fighters were already preparing to receive the second mission, so the pursuit was weak. Two damaged bombers landed in neutral Switzerland, where their crews were interned; one crashed in Italy, and five ditched in the Mediterranean for lack of fuel. The Regensburg force lost 24 aircraft in all. Of the 122 that reached North Africa, more than 60 had battle damage, and at the makeshift bases in Algeria there were neither spare parts nor mechanics to repair them. Many B-17s never returned to England.

Schweinfurt

The Schweinfurt force consisted of 230 bombers in four combat wings, and to muster so many aircraft the 1st Wing even formed composite groups out of squadrons from different units. General Williams flew in person as co-pilot in the leading formation. Because of the delay, ninety-odd British Spitfires were added to the escort, to accompany the bombers as far as Antwerp, where P-47s were to take over. Over the Dutch coast, at about 1.30 p.m., the force ran into cloud that had not been there in the morning. The commander of the leading formation judged that the heavily laden B-17s could not climb above it and led the mission lower, at about 5,000 metres instead of the planned 7,000–8,000. This made the defenders’ task easier still.

This time more than three hundred fighters from over twenty airfields were waiting for the Americans, including night fighters thrown into the battle by day. German pilots attacked the leading wing incessantly from the front, on a collision course. Twin-engined Bf 110s and single-engined Bf 109s also joined in, armed with unguided rockets fired from tubes under their wings – a new weapon that broke up the tight formations from beyond the range of the Fortresses’ machine guns. The Spitfires and P-47s had to turn back almost as soon as battle was joined. When at about 2.36 p.m. the formation turned towards its target over Worms, the Germans already knew where it was heading. The leading wing, which had set out 57 strong, reached Schweinfurt more than a dozen bombers short; in all, 22 B-17s were shot down before the target.

At 2.57 p.m. the first formations released their bombs; the following ones bombed for 24 minutes, increasingly blindly, as smoke from the earlier explosions obscured the target. About 180 bombers dropped 424 tons of bombs, including 125 tons of incendiaries. By American calculations, 80 bombs hit the two largest factories, Kugelfischer and VKF I; fires destroyed halls and machinery as the oil used in machining caught light. 203 inhabitants of Schweinfurt were killed. On the way back the German fighters, having refuelled, attacked again, now singling out above all damaged aircraft that could not keep up with the formation. Only between 4.20 and 5 p.m. did nearly two hundred P-47s and Spitfires of the withdrawal escort appear over Belgium. The Schweinfurt force lost 36 bombers.

The balance

In all, 60 of the 376 B-17s did not return – 16 per cent. The Americans listed 552 airmen as missing; roughly half became prisoners of war, and a dozen or more – about twenty according to some sources – were interned in Switzerland. Depending on the method of counting, between 55 and more than 90 aircraft were damaged, many of which never returned to service. The bombers’ gunners claimed 288 German fighters shot down, and the escort pilots several dozen more. According to its own records, the Luftwaffe lost 25–27 aircraft that day. Such over-claiming by gunners, several of whom in the heat of battle would fire at the same aircraft, was common throughout the war, but in the summer of 1943 it allowed the command to believe that the bombers were winning their duel with the fighters.

What was achieved

The aerial photographs that reached headquarters on the evening of 17 August left no doubt: Regensburg had been hit well, Schweinfurt much less well than intended. Even so, the reports presented the results as better, and the losses as less severe, than they were. The Messerschmitt works soon resumed partial production and began dispersing the manufacture of components to smaller plants in the area; the shortfall in fighters, estimated at anything up to several hundred aircraft, was spread over several months.

At Schweinfurt the armaments minister, Albert Speer, recorded an immediate 34 per cent drop in ball-bearing production. The shortages were, however, covered by stocks dispersed throughout Germany and by imports from Sweden, and the works gradually restored production. Speer wrote after the war that the Allies had made two mistakes: they had divided their forces instead of throwing everything at the bearings, and they had not repeated the attack at once, before the Germans could recover. The bearing industry, he concluded, was vulnerable to a sustained, systematic campaign, but not to a single raid.

The shock within the Luftwaffe was nevertheless serious. Hitler and Hermann Göring blamed the air force command for letting day bombers fly across the whole Reich while the RAF burned its cities by night. The Luftwaffe Chief of the General Staff, Colonel General Hans Jeschonnek, criticised since Stalingrad and Hamburg, shot himself on 18 August, the day after the two raids, near the Luftwaffe staff headquarters in the Rominten Heath. In the following months the Luftwaffe pulled more and more fighter units back from the Eastern Front and the Mediterranean to defend the Reich, weakening itself where the land armies were fighting.

Significance

The Schweinfurt–Regensburg raid was the first great air battle over the Reich in which the Americans learned what a daylight mission deep into Germany without fighter cover would cost. The 1st Wing spent three and a half hours over occupied territory, more than two of them – including the whole time over Germany itself – without any escort. Even so, the command decided that Schweinfurt had to be attacked again, and in the same way.

The second raid, on 14 October 1943, went down in history as “Black Thursday”: of 291 B-17s, 60 did not return – more than 20 per cent of the force. After it the Eighth Air Force suspended unescorted missions deep into Germany for several months. Arnold pressed for the production of drop tanks and long-range fighters. The breakthrough came with the P-51 Mustang, which from the turn of 1943 and 1944 accompanied the bombers all the way to the target. In January 1944 General James Doolittle took command of the Eighth Air Force and ordered the fighters not to stick to the bombers but to hunt German fighters. In February 1944, during “Big Week”, the Americans returned to the aircraft factories – including Regensburg and Schweinfurt – and over the following months won the battle for air superiority, without which there would have been no landing in Normandy.

The lesson of 17 August 1943 became a classic argument in the debate over the effectiveness of strategic bombing: a precise blow at a “bottleneck” could inflict heavy damage, but without persistence and without command of the air the enemy always found a way round it.