Douglas C-52

DC-3
A DC-3 operated in period Scandinavian Airlines colors by Flygande Veteraner flying over Lidingö, Sweden (1989)
Role	Airliner and transport aircraft
National origin	United States
Manufacturer	Douglas Aircraft Company
First flight	December 17, 1935
Introduction	1936
Status	In active service
Produced	1936–1942, 1950
Number built	607
Unit cost	US$79,500 (equivalent to $1,388,742 in 2016)
Developed from	Douglas DC-2
Variants	Douglas C-47 Skytrain Lisunov Li-2 Showa/Nakajima L2D Basler BT-67 Conroy Turbo Three Conroy Tri-Turbo-Three

The Douglas DC-3 is a fixed-wing propeller-driven airliner. Its cruise speed (207 mph or 333 km/h) and range (1,500 mi or 2,400 km) revolutionized air transport in the 1930s and 1940s. Its lasting effect on the airline industry and World War II makes it one of the most significant transport aircraft ever made.

The DC-3 was a twin-engine metal monoplane, developed as a larger, improved 14-bed sleeper version of the Douglas DC-2. It had many exceptional qualities compared to previous aircraft. It was fast, had a good range and could operate from short runways. Its construction was all-metal. It was reliable and easy to maintain and carried passengers in greater comfort. Before the war it pioneered many air travel routes. It was able to cross the continental United States, making transcontinental flights and worldwide flights possible, and is considered the first airliner that could make money by carrying passengers alone.

Civil DC-3 production ended in 1942 with 607 aircraft being produced. However, together with its military derivative, the C-47 Skytrain (designated the Dakota in British Royal Air Force (RAF) service), and with Russian- and Japanese-built versions, over 16,000 were built. Following the Second World War, the airliner market was flooded with surplus C-47s and other ex-military transport aircraft, and Douglas' attempts to produce an upgraded DC-3 were a failure due to cost.

While the DC-3 was soon made redundant on main routes by more advanced types such as the Douglas DC-6 and Lockheed Constellation, the design continued to prove exceptionally adaptable and useful. Large numbers continue to see service in a wide variety of niche roles well into the 21st century. In 2013 it was estimated that approximately 2,000 DC-3s and military derivatives were still flying, a testament to the durability of the design.

"DC" stands for "Douglas Commercial". The DC-3 was the culmination of a development effort that began after an inquiry from Transcontinental and Western Airlines (TWA) to Donald Douglas. TWA's rival in transcontinental air service, United Airlines, was starting service with the Boeing 247 and Boeing refused to sell any 247s to other airlines until United's order for 60 aircraft had been filled. TWA asked Douglas to design and build an aircraft that would allow TWA to compete with United. Douglas' design, the 1933 DC-1, was promising, and led to the DC-2 in 1934. The DC-2 was a success, but there was room for improvement.