The Douglas C-84 was the designation given to four in-service DC-3Bs impressed by the USAAF during 1942. The DC-3 was produced in two main civil versions - the DST, or Douglas Sleeper Transport, which used convertible bed/ seats and the DC-3, which used traditional airline seats. The DC-3B combined the two, and had convertible seats in the front part of the cabin and normal seats in the rear part.
Four of these aircraft were impressed by the USAAF during 1942, with the designation C-84. Their military serial numbers were 42-57157, 42-57511, 42-57512and 42-57513. All four were powered by the SGR-1820-G202A engines, which had the military designation of R-1820-71 Cyclone. The aircraft were later returned to TWA.