Douglas DC-3

The Douglas DC-3 is a fixed-wing propeller-driven airliner. Its speed and range revolutionized air transport in the 1930s and 1940s. Its lasting impact on the airline industry and World War II makes it one of the most significant transport aircraft ever made.

The major military version was designated the C-47 Skytrain, of which more than 10,000 were produced.

Many DC-3s and converted C-47s are still used in all parts of the world.

Design and development
The designation "DC" stands for "Douglas Commercial". The DC-3 was the culmination of a development effort that originated out of an inquiry from Transcontinental and Western Airlines (TWA) to Donald Douglas. TWA's rival in transcontinental air service, United Airlines, was inaugurating 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 enable TWA to compete with United. Douglas' resulting design, the 1933 DC-1, was promising, and led to the DC-2 in 1934. While the DC-2 was a success, there was still room for improvement.

The DC-3 was the result of a marathon telephone call from American Airlines CEO C. R. Smith to Donald Douglas, during which Smith persuaded a reluctant Douglas to design a sleeper aircraft based on the DC-2 to replace American's Curtiss Condor II biplanes. 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 (for Douglas Sleeper Transport) first flew on December 17, 1935 (the 32nd anniversary of the Wright Brothers' flight at Kitty Hawk, North Carolina). A version with 21 passenger seats instead of the sleeping berths of the DST was also designed and 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.

The amenities of the DC-3 and DST popularized air travel in the United States. With only three refueling stops, eastbound transcontinental flights crossing the U.S. in approximately 15 hours became possible. Westbound trips took 17$1/2$ hours due to prevailing headwinds—still a significant improvement over the competing Boeing 247. During an earlier era, such a trip would entail short hops in slower and shorter-range aircraft during the day, coupled with train travel overnight.

A variety of radial engines were available for the DC-3 throughout the course of its development. 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 offered better high-altitude and single engine performance. Three DC-3S Super DC-3s with Pratt & Whitney R-2000 Twin Wasps were built in the late 1940s.

Production
Total production of all derivatives was 16,079. More than 400 remained in commercial service in 1998. Production was as follows:
 * 607 civil variants of the DC-3.
 * 10,048 military C-47 derivatives were built at Santa Monica, California, Long Beach, California, and Oklahoma City.
 * 4,937 were built under license in Soviet Union as the Lisunov Li-2 (NATO reporting name: Cab).
 * 487 Mitsubishi Kinsei-engined aircraft were built by Showa and Nakajima in Japan, as the L2D2–L2D5 Type 0 transport (Allied codename Tabby).

Production of civil DC-3s ceased in 1942; military versions were produced until the end of the war in 1945. In 1949, a larger, more powerful Super DC-3 was launched to positive reviews. However, the civilian market was flooded with second-hand C-47s, many of which were converted to passenger and cargo versions. As a result only three Super DC-3s were built and delivered for commercial use the following year. The prototype Super DC-3 served the US Navy with the designation YC-129 alongside 100 R4Ds that had been upgraded to the Super DC-3 specification.

Turboprop conversions


From the early 1950s, some DC-3s were modified to use Rolls-Royce Dart engines, as in the Conroy Turbo Three. Other conversions featured Armstrong Siddeley Mamba and Pratt & Whitney PT6A turbines.

The Dodson International Turbo Dakota DC-3 is a conversion with an extended fuselage and with Pratt & Whitney Canada PT6A-65AR engines fitted.

The Basler BT-67 is a conversion of the DC-3/C-47. Basler refurbishes C-47s and DC-3s at Oshkosh, Wisconsin, fitting them with Pratt & Whitney Canada PT6A-67R turboprop engines, lengthening the fuselage by 40 in with a fuselage plug ahead of the wing and strengthening the airframe in selected areas.

Braddick Specialised Air Services International PTY Ltd in South Africa is another company able to perform a Pratt & Whitney PT6 turboprop conversion of DC-3s. Over 50 DC-3/C-47s / 65ARTP / 67RTP / 67FTPs have been modified.

Conroy Aircraft also made a three engine conversion with Pratt & Whitney Canada PT6 called the Conroy Tri-Turbo-Three.

Operational history
American Airlines inaugurated passenger service on June 26, 1936, with simultaneous flights from Newark, N.J. and Chicago, IL. Early U.S. airlines like American, United, TWA and Eastern ordered over 400 DC-3s. These fleets paved the way for the modern American air travel industry, quickly replacing trains as the favored means of long-distance travel across the United States. A nonprofit group, Flagship Detroit Foundation, continues to operate the only original American Airlines Flagship DC-3 with air show and airport visits throughout the U.S.

In 1936, KLM Royal Dutch Airlines received their first DC-3, which replaced the DC-2 in service from Amsterdam via Batavia (now Jakarta) to Sydney, by far the longest scheduled route in the world at the time.

The first airline in Latin America to use DC-3s was Cubana de Aviación, initially placing them in service on domestic routes, and then using them to start their first scheduled international service from Havana to Miami in 1945. This was the first scheduled service to Miami by a Latin American airline. Cubana used DC-3s on some domestic routes well into the 1960s.

Piedmont Airlines operated DC-3/C-47s from 1948 to 1963. A DC-3 painted in the representative markings of Piedmont, operated by the Carolinas Aviation Museum, was retired from flight in March 2011. Both Delta Air Lines and Continental Airlines once operated commemorative DC-3s wearing period markings.

During World War II, many civilian DC-3s were drafted for the war effort and just over 10,000 US 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 Showa L2D (487 aircraft) and in the USSR 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 front line 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, jump-started the worldwide post-war air transport industry. While aviation in pre-war Continental Europe had used the metric system, the overwhelming dominance of C-47s and other US war-surplus types cemented the use of nautical miles, knots and feet in post-war 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 their 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.

Douglas DC-3 today
There are still small operators with DC-3s in revenue service and as cargo aircraft. The common saying among aviation buffs and pilots is that "the only replacement for a DC-3 is another DC-3". The aircraft's legendary ruggedness is enshrined in the lighthearted description of the DC-3 as "a collection of parts flying in loose formation." Its ability to take off and land on grass or dirt runways makes it popular in developing countries, where runways are not always paved.

Some uses of the DC-3 include aerial spraying, freight transport, passenger service, military transport, missionary flying, and sport skydiving shuttling and sightseeing.

Perhaps unique among prewar aircraft, the DC-3 is in daily use. The very large number of civil and military operators of the DC-3/C-47s and related types, means that a listing of all the airlines, air forces and other current operators is impractical. As of 2012, DC-3 #10 is still used daily for flights in Colombia. Buffalo Airways, based in Canada's Northwest Territories, operates scheduled DC-3 passenger service between their main base in Yellowknife and Hay River, plus some passenger charter operations, using DC-3s. Some DC-3s are also used by the airline for cargo operations.

The oldest surviving DST is N133D, the sixth Douglas Sleeper Transport built in 1936. This aircraft was delivered to American Airlines on July 12, 1936 as NC16005. The aircraft is at Shell Creek Airport (F13), Punta Gorda, Florida, where it is undergoing restoration. The aircraft will be restored back to Douglas Sleeper Transport standards, and full airworthiness.

The oldest DC-3 still flying is the original American Airlines Flagship Detroit (c/n 1920, #34 off the Santa Monica production line), which can be seen at airshows around the United States and is owned and operated by the nonprofit Flagship Detroit Foundation.

Basic price of a new DC-3 in 1936 was around £18-23,000 and by 1960 used examples were available for £25,000.

A 1943 DC-3 was installed as a major design element atop architectural renovations at The Roasterie in Kansas City, Missouri.

Variants

 * DST
 * Douglas Sleeper Transport, the initial variant, 24 passengers during day and fitted out with 16 sleeper accommodation in the cabin for night.


 * DC-3
 * Variant of DST with 21 passenger seats.


 * DC-3A
 * Improved DC-3 with two 1,200 hp (895 kW) Pratt & Whitney R-1830-21 radial piston engines.


 * DC-3B
 * Improved DC-3 with two Wright R-1820 Cyclone engines.


 * DC-3C
 * Designation for ex-military C-47, C-53 and R4D aircraft rebuilt by Douglas Aircraft in 1946, given new manufacturers numbers and sold on the civil market.


 * DC-3D
 * Designation for 28 new aircraft completed by Douglas in 1946 using unused components from USAAF C-117s.


 * DC-3S
 * Super DC-3, improved DC-3 with a new wing and tail, and fitted with two Pratt & Whitney R-2000 engines of increased horsepower. Five completed by Douglas for civil use using existing surplus secondhand airframes. Designation also used for examples of the 100 US Navy R4Ds that had been converted by Douglas to this standard as R4D-8s (later C-117Ds), that entered civil use after retirement from the military.


 * LXD1
 * A single DC-3 supplied for evaluation by the Imperial Japanese Navy Air Service.


 * C-41A
 * A single DC-3A (40-070) modified as a VIP transport, powered by two 1,200 hp (895 kW) Pratt & Whitney R-1830-21 radial piston engines, used to fly the Secretary of War. (The Douglas C-41 was not a DC-3 derivative but a modification of a Douglas C-33.)


 * C-48
 * One former United Air Lines DC-3A impressed.


 * C-48A
 * Three impressed DC-3As with 18-seat interiors.


 * C-48B
 * Sixteen impressed former United Air Lines DST-As with 16-berth interior used as air ambulances.


 * C-48C
 * Sixteen impressed DC-3As with 21-seat interiors.


 * C-49
 * Various DC-3 and DST models, 138 impressed into service as C-49, C-49A, C-49B, C-49C, C-49D, C-49E, C-49F, C-49G, C-49H, C-49J, and C-49K.


 * C-50
 * Various DC-3 models, 14 impressed as C-50, C-50A, C-50B, C-50C and C-50D.


 * C-51
 * One aircraft ordered by Canadian Colonial Airlines impressed into service, had starboard-side door.


 * C-52
 * DC-3A aircraft with R-1830 engines, five impressed as C-52, C-52A, C-52B, C-52C and C-52D.


 * C-68
 * Two DC-3As impressed with 21-seat interiors.


 * C-84
 * One impressed DC-3B aircraft.


 * R4D-2
 * Two Eastern Air Lines DC-3s impressed into USN service as VIP transports, later designated R4D-2F and later R4D-2Z.


 * R4D-4
 * Ten impressed DC-3s for the US Navy


 * R4D-4R
 * Seven impressed DC-3s as staff transports for the US Navy.


 * R4D-4Q
 * Radar countermeasures version of R4D-4 for the US Navy.


 * Dakota II
 * RAF designation for impressed DC-3s

Conversions

 * Airtech DC-3/2000
 * DC-3/C-47 engine conversion done by Airtech Canada, first offered in 1987. Powered by two PZL ASz-62IT radial engines.


 * Basler BT-67
 * DC-3/C-47 conversion with a stretched fuselage, strengthened structure, modern avionics, and powered by two Pratt & Whitney Canada PT-6A-67R.


 * BSAS C-47TP Turbo Dakota
 * A South African C-47 conversion for the South African Air Force by Braddick Specialised Air Services, with two Pratt & Whitney Canada PT6A-65R turboprop engines, revised systems, stretched fuselage and modern avionics


 * Conroy Turbo Three
 * One DC-3/C-47 converted by Conroy Aircraft with two Rolls-Royce Dart Mk. 510 turboprop engines.


 * Conroy Super-Turbo-Three
 * Same as the Turbo Three but converted from a Super DC-3. One converted.


 * Conroy Tri-Turbo-Three
 * One DC-3/C-47 converted by Conroy Aircraft with three Pratt & Whitney Canada PT-6A turboprops.


 * Dodson International Turbo Dakota DC-3
 * DC-3/C-47 conversion with a stretched fuselage, strengthened wing center section and updated systems; and powered by two Pratt & Whitney Canada PT6A-65AR turboprop engines


 * TS-62
 * Douglas-built airframe fitted with Russian Shvetsov ASh-62IR radial engines after World War II due to shortage of American engines in the Soviet Union


 * TS-82
 * Similar to TS-62, but with Shvetsov ASh-82FN radial engines of 1,650 hp


 * USAC DC-3 Turbo Express
 * A turboprop conversion by the United States Aircraft Corporation, fitting Pratt & Whitney Canada PT6A-45R turboprop engines with an extended forward fuselage to maintain center of gravity. First flight of the prototype conversion, (N300TX), was on July 29, 1982.

Military and foreign derivatives

 * Douglas C-47
 * Production military DC-3A variant.


 * Showa/Nakajima L2D
 * 487 License built DC-3s and derivatives for the IJNAS.


 * Lisunov Li-2 / PS-84
 * 4,937 DC-3 derivatives license-built in the USSR.