It is said that the intention to use electric power for almost all of the aircraft's auxiliary systems (also a fact for the successful Fw 190 fighter), requiring the installation of a large number of electric motors and wiring led to the nickname for the Fw 191 of ""Das fliegende Kraftwerk"" (the flying powerstation). This also had the detrimental effect of adding even more weight to the overburdened airframe, plus there was also the danger of a single enemy bullet putting every system out of action if the generator was hit. Dipl. Ing Melhorn took the Fw 191 "V1" on its maiden flight early in 1942, with immediate problems arising from the lower rated engines not providing enough power, as was anticipated. One surprising problem that was encountered were the Multhopp-Klappe, which presented severe flutter problems when extended, and pointed to the need for a redesign. At this point, only dummy gun installations were fitted and no bomb load was carried. After completing ten test flights, the Fw 191 "V1" was joined by the similar "V2", but only a total of ten hours of test flight time was logged. The 2,500 PS (2,466 hp, 1,839 kW) Junkers Jumo 222 engines which would have powered the Fw 191 proved troublesome. In total only three prototype aircraft, "V1", "V2" and "V6", were built. The project was crippled by engine problems and an extensive use of electrical motor-driven systems. Problems arose almost immediately when the Jumo 222 engines were not ready in time for the first flight tests, so a pair of 1,560 PS (1,539 hp, 1,147 kW) BMW 801A radial engines were fitted. This made the Fw 191 "V1" seriously underpowered. Another problem arose with the RLM's insistence that all systems that would normally be hydraulic or mechanically activated should be operated by electric motors.