The BMW 003 utilized nearly the same starting method as its slightly more powerful Jumo 004 competitor: one of Norbert Riedel's 10 PS flat-twin two-stroke engines, installed within the engine's intake diverter as a mechanical APU, to get the 003's central shaft rotating for operation. An American military-authored post-war review of the BMW 003 stated that an electric starter of some sort was used to "turn over" the Riedel APU, with no existing photos of either wartime or restored BMW 003s showing the "D-shape" pull handle so prominent on the noses of many museum-preserved Jumo 004's intake diverters.