They claimed three of the 40 defending fighters losing one. From 4 September Polish aerial resistance had been reduced, and consequently were ordered to conduct a larger number of close air support operations. I./ZG 76 was temporarily transferred to Ulrich Grauert's 1. Fliegerdivision and fought in the Battle of Iłża from 9 September. After the Polish capitulation following the Soviet Invasion of Poland on 17 September 1939, ZG 76 reorganised in the Phoney War period. II. and III./ZG 76 finally were able to convert from the Bf 109 to Bf 110 and shed their Jadggruppe designations. ZG 76 flew protection patrols (Defence of the Reich) over the German North Sea coast in late 1939. Elements of it took part in the Battle of the Heligoland Bight on 18 December 1939 and the wing claimed five Vickers Wellington bombers shot down. RAF losses were 12 bombers destroyed, three damaged and 57 men killed, though German claims were far higher. Norwegian campaign On 9 April 1940, German forces began Operation Weserübung, an invasion of Denmark and Norway. X Fliegerkorps was allocated to the operation, which was conducted in cooperation with the German Army and the Kriegsmarine. The air corps was commanded by Generalleutnant Hans Ferdinand Geisler. Only I./ZG 76 from the wing participated based at airstrips near Westerland. 3. Staffel of Zerstörergeschwader 1 (ZG 1—1st Destroyer Wing) was attached to it. The immediate objective was to secure airfields in northern Denmark to secure the air space and communications links to the Norwegian capital Oslo from Royal Navy intervention. The German invasion of Denmark was carried out in the space of 24 hours. 1./ZG 76 assisted in the seizure of Aalborg airport on the northern Danish coast granting air superiority over the Skagerrak. Signallers, ground crews, clerks and essential equipment was flown in by Junkers Ju 52s from KGzbV 1. II./KGzbV 1 flew to Oslo Airport, Fornebu to land soldiers and Fallschirmjäger battalions. Lent and 1./ZG 76 gave air cover. The staffel claimed one Royal Norwegian Air Force Gloster Gladiator in combat and two on the ground in exchange for one Ju 52. Commander Hansen and Helmut Lent maintained over claiming an RAF Coastal Command Short Sunderland probing Oslo fjord. The Haerens Flygevåpen possessed only 24 combat aircraft (13 serviceable) and five Tiger Moth trainers. Most flew north to continue the fight against the invaders. Six aircraft, including four Curtiss P-36 Hawks, were