chequered past. These units had lost gruppen and staffeln to the German night fighter force but were resurrected in the close air support role where the Luftwaffe maintained a measure of control. The Oberkommando der Luftwaffe still regarded the heavy armament of the Bf 110, and the emerging Messerschmitt Me 410, as ideal bomber-destroying weapons in areas free of American long-range fighter escorts. ZG 26, which had lost one group to NJG 1 in 1941, gained II./ZG 26 back through the renaming and assignment of III./ZG 1. Hitler favoured the Rheinmetall BK-5 cannon for use in the Me 410 and they equipped II./ZG 26. The recoil and feed mechanisms were not designed for aerial combat, the gun having been designed initially as an anti-tank weapon. The weapon frequently jammed and rarely could a pilot fire off more than a single round before the gun ceased to function. The fighters could carry an additional Werfer-Granate 21 aerial mortar, as could the Bf 109 or Focke-Wulf Fw 190. In addition, II./ZG 26 was placed under the command of Eduard Tratt, regarded as the leading Zerstörer pilot of the war. By the second week in October, 1943, ZG 26 was operating as a three-gruppen wing. On 10 October 1943, ZG 26 made its first notable interception of an American heavy bomber formation. On this date, Eighth Air Force planners decided to keep the pressure of the Combined Bomber Offensive on the Luftwaffe fighter force. Jagddivision 2 committed 350 fighters in at least 13 Jagd and Zerstörergruppen to defend the day's target, the city of Münster. JG 1 and JG 26 Bf 109s and Fw 190s attacked the 14th Bombardment Wing with success. The 390th Bomb Group, 90th Bomb Group and 100th Bomb Group formations were broken up and suffered heavy losses. The situation allowed Major Karl Boehm-Tettelbach, commanding III./ZG 26, to attack the shattered wing, leading the 3rd Bombardment Division. In total 30 B-17 Flying Fortress bombers were shot down, along with a single P-47 Thunderbolt fighter. The cost was 25 German fighters and 12 airmen killed. Nine were Bf 110s and Me 410s. It was clear that the destroyer wings required protection from American fighter escorts. In 1944 the long-range USAAF fighter escorts began to appear. In February, Big Week commenced a systematic series of operations against the Luftwaffe's combat units and supporting industry. In a prelude the Eighth Air Force struck