Aviation in World War II were struggling to re-equip with similarly modern types and to train up aircrew. Early German successes, with the notable assistance of the Junkers Ju 87 "Stuka" dive-bomber, overran Europe and left Britain open to attack. During the ensuing Battle of Britain, the British fighter squadrons had to quickly relearn the old tactical lessons from the first war. Initially the RAF fighters flew in a tight three-fighter arrowhead formation, soon changing to the looser four-aircraft arrangement which the Germans called the "finger-four." They soon also relearned the value of climbing above your opponent before attacking. At the same time, the development
Junkers aircraft engines, albeit in the absence of its founder, who had been removed by the Nazis in 1934. The history of Junkers aircraft production begins with the Junkers J 1 mid-wing monoplane (not to be confused with the later, all-metal sesquiplane ground attack aircraft with the "IdFlieg" designation J.I which had a factory designation of J 4). Research for this aircraft began in 1914 and was interrupted by the start of the First World War. The prototype aircraft, named the "Blechesel" (Tin or Sheet-metal Donkey), was completed in very late 1915 after the outbreak of the war. This aircraft is