The Heinkel He111 provided the Luftwaffe with a fast, manoeuvrable medium bomber which it used as a spearhead for the Blitzkrieg tactics so successfully employed during the early campaigns of World War Two. The He111's defensive shortcomings were harshly demonstrated in 1940 and 1941, but the Germans had little alternative than to continue production of an ageing and inadequate aircraft.
Designed in 1934, the Heinkel He111 first appeared as a high speed civil airliner/transport. The first bomber deliveries were made in 1936 and a number were sent to Spain the following year. By providing support for the Spanish Nationalist forces the Germans could test their new equipment and tactics under operational conditions.
In 1940 the variants in use by the Luftwaffe were the He111H and the He111P which introduced the all-glazed asymmetrical nose. In daylight attacks the He111 proved vulnerable to fighter attack, being too slow to take effective avoiding action and too poorly armed to defend itself.
He111 formations suffered such heavy losses that by mid September it was obvious to the Luftwaffe that a change of tactics must be introduced, so from the 16 September the Heinkel bomber was largely confined to night attacks against Great Britain.