|Heinkel He-111H-23 (701152 'NT+SL' and 8471M). The He-111 was designed as a high speed medium bomber and civil transport in 1934. The first bombers were delivered in 1936 and were first used as such in the following year during the Spanish Civil War by the Nationalist forces. This proved an ideal testing ground. In 1940 the fully glazed nose versions (He-111H and He-111P) were introduced. During daylight raids they were very vulnerable to fighter attack due to their poor defensive armament and their lack of speed. Following heavy losses their role was switched to night attacks against Great Britain.