High Quality Content by WIKIPEDIA articles! The Battle of the Heligoland Bight was the first "named" air battle of the Second World War, which began the longest air campaign of the war, the Defence of the Reich. On 18 December 1939, a force of three RAF bomber squadrons with a total of 24 aircraft set off to engage German ships in the Heligoland Bight and sink or damage as many as possible. Two turned back owing to engine trouble before reaching German airspace, and the remaining 22 aircraft pressed the attack. Warned of their approach by the experimental Freya radar, Luftwaffe fighters attacked the formation and shot down 10 of the bombers. Two more were forced to ditch before reaching Britain, and three more were destroyed in crash landings. In total, 15 of the 24 Wellingtons were lost, for the cost of 2 German fighters shot down.