In contrast to Royal Air Force Bomber Command’s flush of victory after the Hamburg raids in 1943, (see No. 5 in the series, The Berlin Raids) 8th Air Force Bomber Command was still reeling from the defeat of the Schweinfurt-Regensburg raids in August and October of the same year.

After inflicting such heavy losses, the Luftwaffe thought they had found a way to stop the American bomber offensive in its tracks. And they had. The Army Air Forces suspended all raids beyond the range of friendly fighter escort. Like Bomber Command after Hamburg, however, the Luftwaffe’s confidence was misplaced. Allied tactics had changed.

Various factors, from the weather to errors in timing, kept two separate forces of bombers from coordinating their attacks during the first raid. Part of the fighter escort of P-47s, which anyway barely had the range to penetrate the German border, also failed to rendezvous with the bombers, and the result was the loss of 60 bombers from a force of 377. Another 55 bombers were marooned in North Africa (Schweinfurt-Regensburg was also the first “shuttle” mission), too damaged to make it back to England. A second raid of 294 bombers returned to Schweinfurt on Oct. 14, and again 60 bombers were shot down, almost 20 percent of the force. Such losses were unsustainable.

Because the big B-17 and B-24 bombers had to fly unescorted during much of their missions over Germany, the Luftwaffe was able to attack them not only with more heavily armed Fw 190s and Bf 109s, using cannon as well as wing-mounted 21-cm rockets, but with twin-engined fighters such as the Bf 110 and Me 410, to break up the formations. The German pilots had also learned from experience that the best way to attack the bombers was head on, despite the furious closing rates, split-second firing windows, and serious danger of collision that could be as unnerving for the attacking fighter pilots as it was for those in the bomber being attacked. Wrote J. Douglas Harvey in Boys, Bombs, and Brussels Sprouts:

I’d look up and see these guys coming in and I’d try and scrunch down behind the skin of the airplane, which seemed like 1/10,000th of an inch thick. They’d come in and the rate of closure would be between 400 and 500 miles an hour and I would always wonder if they were gonna break or collide with us. They’d come in shooting. You could see the wings “blinking” and you knew they weren’t saying “Hello Charlie” in Morse code. … That rate of closure. They were coming in through a hail of lead, and they’d keep on coming. You’d see a wing break off one and he’d spin in, but the rest of them kept on coming. “My God, he’s not gonna break off, he’s not…” Then finally, he’d barrel-roll and go over or under us. They’d pressed home real good.

After inflicting such heavy losses, the Luftwaffe thought they had found a way to stop the American bomber offensive in its tracks. And they had. The Army Air Forces suspended all raids beyond the range of friendly fighter escort. Like Bomber Command after Hamburg, however, the Luftwaffe’s confidence was misplaced. Allied tactics had changed.

Feb. 20, 1944 marked the start of a campaign to destroy the Luftwaffe on the ground and in the air. The dream of Gen. Henry “Hap” Arnold, Gen. Carl Andrew “Tooey” Spaatz and Lt. Gen. James H. Doolittle, Big Week bombing sorties would attack the German fighter manufacturing plants, fighter component plants, and ball-bearing factories, seeking to destroy the German fighters at the source, before they could come off the assembly lines, as well as making them come up to fight and destroying them in the air. The bombing raids sought to disrupt or end German fighter production, but also acted as bait to lure the German fighters into battle against escorting fighters.

The difference between Big Week and the earlier attempts to destroy the German fighter force through attrition was the development of a true long-range escort: the P-51 Mustang. The Luftwaffe had shattered the American belief that daylight heavy bombers, concentrating their firepower in combat box formations, didn’t need fighter escort. The Schweinfurt-Regensburg missions had proven that.

With the advent of the Merlin-engined Mustang, however, no more would American bombers flying deep into Germany see their escorts have to turn for home halfway to the objective. The Mustang could fly all the way to the target and back, and perform as well or better than any interceptors the enemy could put up to challenge it. Now they were operating in sufficient numbers to escort the bombers to targets in Germany and back, and along with them, shorter-range P-47s and P-38s could also roam at will, strafing airfields or breaking up formations of German fighters before they could get to the bombers. Luftwaffe 275-kill ace Generalleutnant Gunther Rall related the German point of view in Colin D. Heaton and Anne-Marie Lewis’ The German Aces Speak II:

Certainly the Spitfire was excellent, but it didn’t have the endurance of the P-51. I think this was the decisive factor. The P-51s flew for seven hours, and we [in 109s] flew one hour and twenty minutes. Compared to the Mustang, we were really screwed. You would have to get down because you were short on fuel, then look for the nearest air base, and they still had fuel for three hours more. Usually they were hanging around our bases.

On Feb. 20, 1944, almost a thousand bombers attacked German fighter aircraft factories at Brunswick, Oschersleben, Bernberg and Liepzig in the heaviest American raid of the war up to that time. The next day, 8th Air Force bombers returned in almost equal strength. The day after, they were joined by bombers of the 15th Air Force in Italy. Wednesday was a stand-down, but Thursday and Friday, the blows against the aircraft factories and component works continued. More than 2,000 planes set out that Friday for the targets.

The Luftwaffe rose in force, using tactics and technologies that had proved so successful against the unescorted American bombers. But this time, the bombers were escorted by fighters, and Luftwaffe aircraft encumbered by heavy armament to destroy bombers, including rockets or gondolas for 20mm cannon underwing, were no match for marauding Mustangs. The twin-engined heavy fighters were almost completely helpless against the escorts. One squadron had 11 of 13 aircraft shot down in minutes. Worse for the Luftwaffe, its pilots now had to live with the same fears which beset Bomber Command pilots every night – the chance of being attacked during any part of the mission from takeoff to landing. In addition to the losses suffered in battling the bomber formations, it became increasingly difficult to train new pilots, with Allied fighters roving over Germany looking for targets.

But this time, the bombers were escorted by fighters, and Luftwaffe aircraft saddled with the drag of launch tubes for rockets, or underwing gondolas for 20mm cannon to destroy bombers were no match for marauding Mustangs. The twin-engined heavy fighters were almost completely helpless against Allied fighters.

“We paid a price for the air,” Gen. Henry “Hap” Arnold said later of Big Week. “We lost 244 heavy bombers and thirty-three fighter planes during five days.” By the end of Big Week, however, as Walter Boyne wrote in his book Clash of Wings, the 8th and 15th Air Forces had flown 3,800 sorties and dropped nearly 10,000 tons of bombs, more than the 8th Air Force had dropped in its entire first year of operations. More importantly, the Luftwaffe lost more than 2,000 aircraft in February, and a similar number in March. While prodigies of work (Germany had been on single factory shifts until 1942) and clever dispersal of factories eventually brought fighter production figures back up above 1942 levels, the losses of experienced pilots could not be made good. Some 17 percent of Luftwaffe fighter pilots had been lost by the end of Big Week. While fighter pilot losses had already been steadily increasing, the Luftwaffe fighter arm essentially was at the point of collapse by the end of March.

After Big Week, the Luftwaffe had to pick its battles, rising in force only occasionally, and sometimes choosing not to do battle at all. The ultimate result of Big Week, however, was perhaps best expressed in the complete air superiority enjoyed by the Allies during Operation Overlord, the invasion of Normandy in June 1944. As Gen. Dwight D. Eisenhower said to his troops on the eve of the invasion: “If you see fighter aircraft over you, they will be ours.”

This story was originally published on Jun 21, 2016.