In 1932 Heinkel developed the He70 to a Lufthansa airline specification for an aircraft to compete with passenger aircraft being operated by other carriers. The airframe was aerodynamically efficient and was powered by a single BMW VI liquid cooled engine rated at 630hp (470kW). The prototype He 70 first flew at the end of 1932 and early the following year the aircraft achieved a level speed of 376 kph. A second prototype later set eight speed records. The He 70A entered service with Lufthansa in 1934. The pilot sat in an elevated cockpit offset to port with a navigator/radio operator sitting below and behind him. To the rear of the cockpit there was a passenger cabin with four seats. The He70 was developed into a number of military versions that could carry around 300kg of bombs. In 1936 eighteen went into service with the Condor Legion during the Spanish Civil War. The designers of the He70,  Siegfried and Walter Günte, used an elliptical shaped inverted gull wing that they had used on previous designs; a feature they would use later on the He111.

The Heinkel He111 was twin engined development of the He70, with an extended fuselage and bigger wingspan. The prototype first flew on February 25th 1935 registered as a civilian aircraft. To maintain the pretence that this was a civilian airliner, the bomb bay was fitted out as a smoking compartment with four seats. During the mid 30's Heinkel was competing with Junkers and Dornier for military contracts. The He111 had to contend with the Junkers Ju86 and the Dornier Do17. The availability of the Daimler-Benz 600C to power the He111 gave it a massive advantage and it became the main bomber aircraft adopted by the new Luftwaffe.

The first two models to be produced in substantial quantities were the He11E and He11F. These were used by the Condor Legion during the Spanish Civil War. Despite having little defensive armament the He111' s fast speed allowed them to survive many encounters with enemy fighters. This generated a false sense of security, which was to prove disastrous during the Battle of Britain when the He111 was found to be very vulnerable to the fast Hurricanes and Spitfires of the RAF.

Heinkel He111 H

From the poor performance during the Battle of Britain it was recognised that the He111 was unfit for front line service. It was replaced as quickly as possible by the more modern Junkers Ju88. The He111 continued on in service until the end of the war fulfilling support roles. After the war the type saw service with the Spanish Air Force, some using the Merlin engine as the power plant.

Luftwaffe bombers were organised into KampfGeschwader (KG) each made up of three to five Gruppen.  A Gruppe could be comprised of three or four Staffeln, each of between 9 to 16 aircraft.

A Heinkel He111 H