One of the world's truly outstanding aeroplanes, the DC-3 resulted from American Airlines' requirement for a sleeper aircraft for its US transcontinental route. The DC-2 fuselage was too small for this, so, reluctantly, in the autumn of 1934 Douglas agreed to build the DST (Douglas Sleeper Transport) as an enlarged DC-2, with lengthened fuselage, increased span and, most important, an increase of 66cm in fuselage width - allowing up to 28 seats or 14 sleeping berths.

The prototype DST, with 633.4-745kW Wright Cyclone SGR-1820 engines, made its first flight on 17 December 1935 (not inappropriately the 32nd anniversary of the first powered flight by the Wright Brothers). The type entered service with American Airlines on 25 June 1936 over the New York-Chicago route, with transcontinental sleeper services starting on 18 September. The DC-3/DST soon proved itself and orders grew rapidly, with KLM becoming the first operator outside the US. Including 40 DST, 430 DC-3 had been delivered when the USA entered the war - one flew more than 84,000 hours.

The aircraft had such enormous potential that it was ordered in very large numbers by the US armed forces and when production ceased in 1947 Douglas had built 10,654 examples of all civil and military variants; Nakajima and Showa in Japan had built 485 (L2D) and about 2,000 had been built in the USSR as PS-84, but later redesignated Lisunov Li-2 with 742kW Shvetsov engines.

The DC-3 was built in numerous versions and with a wide range of Wright Cyclone and Pratt & Whitney Twin Wasp engines ranging in power from 742 to 894kW. The aircraft were operated on wheels and skis - one even had floats (the XC-47G-DL) - and there was the XCG-17 experimental troop-carrying glider version. Original US military contracts covered 10,047 aircraft of which more than 9,500 were versions of the C-47 Skytrain with reinforced floor and double doors, and 380 G-53 Skytroopers. The US Navy ordered the DC-3 as the R4D. A wide range of military designations was given to civil aircraft impressed by the services before delivery including G-48, C-49, C-50, C-51, G-52, G-68 and C-84. Many military DC-3 were supplied to the US's allies and the 1,900 plus supplied to the RAF were given the name Dakota - a name which has been widely used in place of the correct DC-3 designation.

C-47 made such an important contribution to the US war effort that General Eisenhower considered them to be one of the four most significant weapons of World War II. In the China-Burma-India theatre they 'humped' supplies over the Himalayas from India to China and carried airborne troops on all major invasions. Post-war they contributed to the Berlin Airlift, carried supplies and troops into and wounded men out of Korea, and even fought as heavily armed gun-ships in Vietnam.

After World War II very large numbers of military DC-3 became surplus and were acquired by most of the world's airlines. In the early post-war years they formed the backbone of most airline fleets, initially with austere interiors but later brought up to much higher standards. Some were equipped to carry as many as 36 passengers but 21-28 was standard. Many others were used for cargo and mail.