Tank then took the design directly to Wolfram von Richthofen, chief of the development section of the Technischen Amt, the research and development arm of the RLM. Richtofen was not so convinced that bomber performance would remain superior to fighters, and gave the go-ahead for the construction of three prototypes, but on the condition that they replace the DB 600, which was in extremely short supply, with the less-powerful 515 kW (700 PS) Junkers Jumo 210.