[citation needed] The first example was bench tested around March 1938, but did not reach the design thrust because a small compressor and combustor had been used to reduce the frontal area.

The flight tests were carried out in extreme secrecy, taking off and landing under propeller power, and only flying in the early morning before other workers had arrived.

Testing continued and in November the aircraft was demonstrated to RLM officials in hopes of receiving funding for the development of a larger engine, but nothing seemed forthcoming.

Hans Mauch later told von Ohain the RLM was in fact extremely impressed, but he was concerned that Heinkel's airframe team did not have the knowledge to undertake engine development.

Schelp was not as concerned about where development was taking place, and immediately started funding Heinkel to produce a more powerful engine.