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 T 29 L1a inline engine cowled with its cylinder heads slightly exposed. Pilot and passenger sat side by side over the wing in a cockpit open apart from a longitudinal arch over their heads to protect them like a roll bar, set perpendicularly to the similar cross-fuselage device only used directly "behind" the cockpit on the Junkers J 2, the Junkers J 7 experimental duralumin-structure monoplane and production Junkers D.I fighter of the late World War I years. This unusual feature reminded observers of a handle and earned the J 29 the nickname "Bügeleisen" (en: flat iron). The fuselage tapered to the