The Douglas R5D was the US Navy’s version of the C-54 Skymaster, the military version of the DC-4 airliner. A total of 202 R5Ds were diverted to the Navy from USAAF orders, and it fulfilled the same long range transport role for the Navy as for the Air Force, allowing personnel and urgent cargos to reach the far-flung elements of the Navy during the Second World War.
The R5D-1 was the US Navy’s version of the C-54A. This was a fully militarized version of the DC-4, with a reinforced cargo floor and built in cargo hoist and that could carry 32,000lb of cargo or 50 troops. The R5D-1 had four auxiliary fuel tanks inside the cabin. The navy received 56 R5D-1s. In 1962 surviving staff transports based on the R5D-1 were redesignated as the VC-54N
The R5D-2 was the Navy’s version of the C-54B. These aircraft had two auxiliary fuel tanks in the cabin and two extra tanks in the outer wings. The navy received 30 R5D-2s. In 1962 they became the VC-54P.
The R5D-3 was the Navy’s version of the C-54D, powered by four 1,350hp R-2000-11 engines. It was otherwise similar to the R5D-2. The navy received 86 R5D-3s. Most became C-54Qs in 1962, while a small number of photographic reconnaissance aircraft became RC-54Vs.
The R5D-4 was the Navy’s version of the C-54E. This had a new arrangement of fuel tanks that saw the last cabin tanks replaced by collapsible bag-type fuel tanks in the inner wings. The interior of the twenty R5D-4s could easily be converted between cargo, troop carrier or staff officer transport versions. In 1962 they became the C-54R.
The R5D-5 was the Navy’s version of the C-54G, which differed from the R5D-4 only in having R-2009-9 engines, which provided more power for take-off. The Navy received thirteen R5D-5s. In 1962 most became the VC-54T, while one became a VC-54S staff transport.
This would have been a Navy version of the C-54J, a staff transport based on the C-54G, and lacking the normal cargo carrying capacity of the Skymaster. None were built.