In 1939, the office of the RLM launched the Bomber-B program for a new type of medium bomber capable of carrying a 4,000kg bomb load to any point in the British Isles. Power would be supplied by the Junkers Jumo 9-222 or the Daimler Benz DB-9-604, both were under development. The contract was issued to the firms of Arado, Dornier, Junkers and Focke-Wulf. The first manufacturer to respond was Arado. They submitted the E.340 design which had already reached the mock-up stage. The E.340 layout featured a central gondola and two separate tail booms, in order to guarantee the rear gunner an unobstructed field of fire. However, this revolutionary design was not accepted by the RLM. It was rejected and the design was dropped from the development program. The other three designs responded to the program was the Dornier Do.317, the Junkers Ju.288 and the Focke-Wulf Fw.191. All of them had reached prototype stage and were flights tested. Despite the good flying characteristics of all the prototypes, the RLM decided to cancel the Bomber-B program, on the lack of the intended Jumo power-plant.