Big Brother is Flying
If the C-47/R4D Skytrain — the military version of the Douglas DC-3 airliner — was the most successful transport aircraft of the World War II era, its big brother, the C-54/R5D Skymaster, was certainly a runner up. Shortly after the twin-engine DC-3 first flew in late 1935, a Douglas engineering team led by A. E. Raymond and E. F. Burton began work on a larger and simpler variant of the aircraft. The DC-4E ("E" for experimental) flew on 7 June 1938, but they soon realized that an entirely new design was needed. 1
