Douglas DC-3 Aircraft

The Douglas DC-3 is a fixed-wing propeller-driven airliner with tailwheel-type landing gear. 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.

                                                        Scandinavian Airlines DC-3
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. 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.

Design and Development

"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.

The DC-3 resulted from a marathon telephone call from American Airlines CEO C. R. Smith to Donald Douglas, when Smith persuaded a reluctant Douglas to design a sleeper aircraft based on the DC-2 to replace American's Curtiss Condor II biplanes. (The DC-2's cabin was 66 inches (1.7 m) wide, too narrow for side-by-side berths.) Douglas agreed to go ahead with development only after Smith informed him of American's intention to purchase twenty aircraft. The new aircraft was engineered by a team led by chief engineer Arthur E. Raymond over the next two years, and the prototype DST (Douglas Sleeper Transport) first flew on December 17, 1935 (the 32nd anniversary of the Wright Brothers' flight at Kitty Hawk). Its cabin was 92 in (2.3 m) wide, and a version with 21 seats instead of the 14–16 sleeping berths of the DST was given the designation DC-3. There was no prototype DC-3; the first DC-3 built followed seven DSTs off the production line and was delivered to American Airlines.

The DC-3 and DST popularized air travel in the United States. Eastbound transcontinental flights could cross the U.S. in about 15 hours with three refueling stops; westbound trips against the wind took ​17 ¹⁄₂ hours. A few years earlier such a trip entailed short hops in slower and shorter-range aircraft during the day, coupled with train travel overnight.

A variety of radial engines was available for the DC-3. Early-production civilian aircraft used Wright R-1820 Cyclone 9s, but later aircraft (and most military versions) used the Pratt & Whitney R-1830 Twin Wasp, which gave better high-altitude and single-engine performance. Five DC-3S Super DC-3s with Pratt & Whitney R-2000 Twin Wasps were built in the late 1940s, three of which entered airline service.

Effect of the DC3 on Postwar Civilian Aviation

During World War II, many civilian DC-3s were drafted for the war effort and just over 10,000 U.S. military versions of the DC-3 were built, under the designations C-47, C-53, R4D, and Dakota. Peak production was reached in 1944, with 4,853 being delivered. The armed forces of many countries used the DC-3 and its military variants for the transport of troops, cargo, and wounded.

Licensed copies of the DC-3 were built in Japan as the Showa L2D (487 aircraft); and in the Soviet Union as the Lisunov Li-2 (4,937 aircraft).

Thousands of surplus C-47s, previously operated by several air forces, were converted for civilian use after the war and became the standard equipment of almost all the world's airlines, remaining in frontline service for many years. The ready availability of cheap, easily maintained ex-military C-47s, both large and fast by the standards of the day, jumpstarted the worldwide postwar air transport industry. While aviation in prewar Continental Europe had used the metric system, the overwhelming dominance of C-47s and other U.S. war-surplus types cemented the use of nautical miles, knots and feet in postwar aviation throughout the world.

Douglas developed an improved version, the Super DC-3, with more engine power, greater cargo capacity and a different wing, but with all the bargain-priced surplus aircraft available, they did not sell well in the civil aviation market. Only five were delivered, three of them to Capital Airlines. The U.S. Navy had 100 of its early R4Ds converted to Super DC-3 standard during the early 1950s as the R4D-8, later C-117D. The last U.S. Navy C-117 was retired July 12, 1976. The last U.S. Marine Corps C-117, serial 50835, was retired from active service during June 1982. Several remained in service with small airlines in North and South America in 2006.

A number of aircraft companies attempted to design a "DC-3 replacement" over the next three decades (including the very successful Fokker F27 Friendship), but no single type could match the versatility, rugged reliability and economy of the DC-3. It remained a significant part of air transport systems well into the 1970s.

https://en.wikipedia.org/wiki/Douglas_DC-3