The Heinkel 111 came into WWII aviation history as one of the best medium-range bombers, although its initial combat service with the first-built planes was very short because of airframe and engine problems.
Just after Adolf Hitler became Chancellor of the Third Reich, he began the process of breaking the Versailles Treaty. But Germany was not in a position to challenge Britain and France and the concept of Bomber aviation consisted of building transport planes, which could be converted to bombers when war became inevitable.
On February 24th1935 the new planes first flight took place. Flight performance was satisfactory and the plane returned to factory for improvements. The Reichsluftahrtministerium at the end of 1935 ordered a pre-production batch of 10 aircraft, which received the official name He-111A, unlike the prototype, the He-111A was heavier by 520 kg, and cruising speed was reduced to 168 mph (270 km/h). The new plane was admittedly unsuitable for the Luftwaffe.
This decision was unexpected by Heinkel, who had already initiated flight-testing of the much powerful He-111V5 prototype.
But at the same time while all this was taking place the Chinese military purchasing commission was in Germany. The Chinese-Japanese boarder conflict had generated a mandate from the Chiang Kai-shek government to obtain bombers.
Soon six He-111A's with deleted bombsights and radio equipment were disassembled and shipped to China by sea. At the end of 1936 all six of the new bombers joined the Chinese air forces.
They were first operationally used to attack the Japanese army near Shanghai, being accompanied by Martin 139 and Boeing 281 escort planes. Five of the six He-111A which participated in this mission (with inexperienced Chinese crews) forgot to lift the ventral gunner's position and the Heinkel's fell behind the Martin's and the Boeing's. Japanese fighters shot down three of them, the others returned to base.
The surviving three He-111A's were still in service until the autumn of 1937.
One He-111 was lost in a flying accident in 1939, when a Chinese gunner from another aircraft shot it down by mistake.