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 J 2 fuselage framing, primarily as an engineering exercise, were finished shortly before the end of 1916. It is also thought that the contrasting promise of the advanced, low drag features of the Junkers monoplane aircraft designs, versus the Junkers firm's usage of experimental non-traditional sheet metal materials, and the firm's habit of almost constant experimentation obstructing any future hope of producing its advanced designs for the "Luftstreitkräfte", compelled "IdFlieg" to create the "Junkers-Fokker Aktiengesellschaft", abbreviated as "Jfa" and pronounced as if spelled "iefa" in German, on 20 October 1917, to allow Anthony Fokker, who even flew one of the J 2