21 unguided air-to-air rocket weapon system to the Luftwaffe's single engine day fighter force the previous day, as well as the similarly armed rocket-launching twin-engined Bf 110 Zerstörer heavy fighters, including night fighters, joined the battle as more than 300 fighters from 24 bases opposed the raid. At 14:36 the force diverged from the morning's route at Worms, Germany, alerting the German defenders that the target was Schweinfurt. Losses among the 57 B-17s of the lead wing were so severe that many among its airmen considered the possibility that the wing might be annihilated before reaching the target. However, 15 miles from Schweinfurt, the opposing fighters, after shooting down 22 bombers, disengaged and landed to refuel and re-arm in order to attack the force on its way out. Five miles from Schweinfurt, German anti-aircraft guns began firing an effective flak barrage into the path of the bomber force. At 14:57 approximately 40 B-17s remained of the lead wing when it dropped its bombs on the target area containing five factories and 30,000 workers, followed over a 24-minute span by the remainder of the force. Each wing found increasingly heavy smoke from preceding bomb explosions a hindrance to accuracy. 183 bombers dropped 424.3 tons of bombs, including 125 tons of incendiary bombs. Three B-17s were shot down by flak over Schweinfurt. Fifteen minutes after leaving the target each task force circled over the town of Meiningen to reassemble its formations, then continued west toward Brussels. At approximately 15:30 German fighters renewed their attacks, concentrating now on damaged bombers. Between 16:20 and 17:00 a covering force of 93 P-47s and 95 Spitfires arrived to provide withdrawal support, claiming 21 fighters shot down, but eight more bombers were lost before the force reached the North Sea, where three more crash-landed. The Schweinfurt force lost a total of 36 bombers. Results and losses The Americans listed 55 of their bombers with 552 crewmen as missing after the August 17 double-target mission. About half of those became prisoners of war and 20 were interned. Sixty aircraft were lost over German-controlled territory, in Switzerland, or ditched at sea, with five crews rescued. Seven aircrew were killed aboard bombers returning to base having completed the mission, and twenty-one were wounded. The 60 aircraft lost on a single mission more than doubled the highest previous loss at that time. There were also 55 to 95 additional aircraft badly