For many years after the war, a substantial number of aviation history books and magazine articles that dealt with late World War II German military aviation developments consistently stated that Reichsmarschall Hermann Göring, early in World War II, was becoming so frustrated by the 177A's ongoing engine problems, caused by the twin DB 606 "coupled" powerplants selected for the He 177A design in the pre-war years, that he forbade Ernst Heinkel from doing any work on a separately four-engined version of the 177 airframe, or even mentioning a new "He 277" design with four separate engines – by one account, in the late autumn of 1941 – until Heinkel brought the disagreement directly to Adolf Hitler, who supposedly not only approved of calling the new, separately engined version of the 177 the "He 277", but overruled Göring's prohibition on working on the design (previously called the "He 177B" by Heinkel as a "cover designation" to hide its existence from Göring, and the RLM.)[2][3]