On 14 October 1943 the US 8th Air Force attacked the ball bearing factories at Schweinfurt in central Germany, an industry which was seen as a bottleneck in the German industrial manufacturing system. During the Second Schweinfurt raid, the German air defences inflicted many losses on the bombers, but the city and the industry were severely hit.[1][2] On 20 October, just a week later, the 8th Air Force sent 119 bombers to attack the western town of Düren, near the border city of Aachen, but the German defenders assumed it was really a return to the earlier target.
The Americans reached their target and bombed it, after which they turned for home. At this point German observers reported a large formation of aircraft heading south. In 1973, Alfred Price wrote that this was based on the noise of aircraft, though they were not seen; Adolf Galland attributes this to chaff dropped by the bombers drifting on the wind and registering on German radar.[2]
When it was reported to Hermann Göring, the Luftwaffe leader, the attack on Düren was seen as a ruse and another devastating attack on central Germany was assumed to be underway. The Reichmarschall took command of the air defence and ordered all available fighter aircraft to intercept. As these fighters became airborne and could be heard from the ground or reported by radar, the impression of a huge force of attackers heading south became more pronounced. As they were on the same course as the force that attacked Schweinfurt less than a week before, Göring inferred that this was the target and ordered the fighters to intercept there. As the phantom bombers passed over Schweinfurt without any ill effect, Göring decided that they were heading for Leuna, the synthetic fuel refinery near Leipzig, another sensitive target. When again there was no bombing, Göring suspected an attack on the Skoda Works at Pilsen and diverted the fighters there. By this time, the fighters were running out of fuel and, as the defence system dictated, started to land at the nearest available airfield. As the fighters landed, the attacking force began to melt away.[2] Galland wrote that the sky was clear over Pilsen and ground observers could see there were no bombers, only German fighters.[1] With this, the phantom raid evaporated.