Douglas C-47 Skytrain
The Douglas C-47 is arguably the most successful aircraft to come out of World War II. It was designed in 1935 as the DC-3 commercial airliner. The aircraft was so far ahead of its competitors that over 400 had been built by 1940 when the U.S. Army Air Forces expressed an interest in a militarized cargo and troop transport version. The main modifications from the DC-3 version are a large cargo door on the left side of the aircraft and a strengthened floor. More than 9,500 Skytrains were built for all branches of the American military and for export. Large numbers of C-47s entered civil service after the war and as many as 400 of them were still flying around the world in 2017.