The Douglas C-47 Skytrain or Dakota (RAF designation) is a military transport aircraft developed from the civilian Douglas DC-3 airliner. It was used extensively by the Allies during World War II and remained in front line service with various military operators to the present day.
The C-47 differed from the civilian DC-3 in numerous modifications, including being fitted with a cargo door and strengthened floor, along with a shortened tail cone for glider-towing shackles, and an astrodome in the cabin roof.
During World War II, the armed forces of many countries used the C-47 and modified DC-3s for the transport of troops, cargo, and wounded. The U.S. Naval designation was R4D. More than 10,000 aircraft were produced in Long Beach and Santa Monica, California and Oklahoma City, Oklahoma. Between March 1943 and August 1945 the Oklahoma City plant produced 5,354 C-47s.
The C-47 was vital to the success of many Allied campaigns, in particular those at Guadalcanal and in the jungles of New Guinea and Burma, where the C-47 (and its naval version, the R4D) made it possible for Allied troops to counter the mobility of the light-traveling Japanese army. Additionally, C-47s were used to airlift supplies to the embattled American forces during the Battle of Bastogne. Possibly its most influential role in military aviation, however, was flying "The Hump" from India into China. The expertise gained flying "The Hump" was later be used in the Berlin Airlift, in which the C-47 played a major role, until the aircraft were replaced by Douglas C-54 Skymasters.
A C-47 flown by the China National Airways Corporation (CNAC) pilot Moon Chin, who had previously flown "The Hump" in the aircraft, had a role in the Doolittle Raid. Moon Chin was tasked with flying from Chungking to Myitkyina, a military base in Burma. His aircraft was "jumped" by Japanese fighters and, after landing at a small hidden airstrip to wait for his pursuers to give up the game, he planned to resume his flight to Myitkyina. One of his passengers, "an unshaven, balding, bedraggled American" who was dressed in a combination of civilian clothing and an Army uniform, suggested that he fly to a field in India since the American had heard that Myitkyina had fallen to the Japanese. When Chin's DC-3 arrived at Myitkyina, he found that the base had, indeed, been severely bombed by the Japanese and hundreds of people were milling around the airdrome. Eventually, Chin would carry sixty-eight passengers and a crew of four (including eight stowaways in the aft compartment he did not know about) on the final leg to India. After arriving in India, the tattered American approached Captain Chin and thanked him for the ride. "Believe me, Chin," he began, "if I had had any idea that you were going to jam that many people into this old crate I would have gone home the way I came." Chin inquired as to how that might have been and the American replied "I flew in, by way of Tokyo." The short, balding, bedraggled American was none other than Lt Col Jimmy Doolittle returning from the historic raid on Tokyo. 
In Europe, the C-47 and a specialized paratroop variant, the C-53 Skytrooper, were used in vast numbers in the later stages of the war, particularly to tow gliders and drop paratroops. In the Pacific, with careful use of the island landing strips of the Pacific Ocean, C-47s were even used for ferrying soldiers serving in the Pacific theater back to the United States.
C-47s (about 2,000 received under lend-lease) in British and Commonwealth service took the name Dakota, possibly inspired by the acronym "DACoTA" for Douglas Aircraft Company Transport Aircraft. The C-47 also earned the informal nickname "Gooney Bird" in the European theater of operations.
Other sources attribute this name to the first aircraft, a USMC R2D—the military version of the DC-2—being the first aircraft to land on Midway Island, previously home to the native long-winged albatross known as the gooney bird, which was native to Midway.
Several C-47 variations were used in the Vietnam War by the United States Air Force, including three advanced electronic warfare variations, which sometimes were called "Electric Gooneys" designated EC-47N, EC-47P, or EC-47Q depending on the engine used. EC-47s were also operated by the Vietnamese, Laotian, and Cambodian Air Forces. A gunship variation, using three 7.62 mm Miniguns, designated AC-47 "Spooky", often nicknamed "Puff the Magic Dragon", also was deployed.
Large numbers of DC-3s and surplus C-47s were in commercial use in the United States in the 1940s. In response to proposed changes to the Civil Air Regulations airworthiness requirements that would limit the continuing use of these aircraft, Douglas offered a late 1940s DC-3 conversion to improve takeoff and single-engined performance. The new model, the DC-3S or "Super DC-3", was 39 in (0.99 m) longer. It allowed 30 passengers to be carried, with increased speed to compete with newer airliners. The rearward shift in the center of gravity led to larger tail surfaces and new outer, swept-back wings. More powerful engines were installed along with shorter, jet ejection-type exhaust stacks. These were either 1,475 hp (1,100 kW) Wright R-1820 Cyclones or 1,450 hp (1,081 kW) Pratt & Whitney R-2000s in larger engine nacelles. Minor changes included wheel well doors, a partially retractable tailwheel, flush rivets, and low drag antenna. These all contributed to an increased top speed of 250 mph (400 km/h). With greater than 75% of the original DC-3/C-47 configuration changed, the modified design was virtually a new aircraft. The first DC-3S made its maiden flight on 23 June 1949.
The changes fully met the new FAR 4B airworthiness requirements, with significantly improved performance. However, little interest was expressed by commercial operators in the DC-3S. It was too expensive for the smaller operators which were its main target: only three were sold to Capital Airlines. The U.S. Navy and U.S. Marine Corps had 100 of its R4D aircraft modified to Super DC-3 standards as the R4D-8, later redesignated C-117D.
N1944A parked on ramp near a C-47 in Icelandair colors in Reykjavik, Iceland in 2011: The C-47 in Army colors is en route to the EAA AirVenture Museum in Oshkosh, Wisconsin from its previous home at Cotswold Airport.
Gunship aircraft with three side-firing .30 in (7.62 mm) Minigun machine guns
C-47D with equipment for the Electronics Calibration, of which 26 were so converted by Hayes in 1953; prior to 1962 was designated AC-47D
C-47D modified for test roles
C-47D equipped for photographic reconnaissance and ELINT missions
C-47D equipped for Search Air Rescue; redesignated HC-47D in 1962
C-47D equipped for VIP transport role
Modified cargo variant with space for 27–28 passengers or 18–24 litters
YC-129 redesignated, Super DC-3 prototype for evaluation by USAF later passed to USN as XR4D-8
C-47H/Js equipped for the support of American Legation United States Naval Attache (ALUSNA) and Military Assistance Advisory Group (MAAG) missions
C-47A and D aircraft modified for ELINT/ARDF mission, N and P differ in radio bands covered, while Q replaces analog equipment found on the N and P with a digital suite, redesigned antenna equipment and uprated engines
One C-47M modified for high altitude work, specifically for missions in Ecuador
Troop transport version of the C-47
One aircraft with full-span slotted flaps and hot-air leading edge deicing
Winterised version of C-53 with extra fuel capacity and separate navigator's station, eight built
C-53 with larger port-side door, 17 built
C-53C with 24V DC electrical system, 159 built
C-47B with 24-seat airline-type interior for staff transport use, 16 built
Three redesignated C-117s used in the VIP role
One C-117C converted for air-sea rescue
High-altitude superchargers removed, one built and conversions from C-117As all later VC-117B
USN/USMC R4D-8 redesignated
USN/USMC R4D-8L redesignated
USN/USMC R4D-8T redesignated
USN R4D-8Z redesignated
Super DC-3 prototype for evaluation by USAF redesignated C-47F and later passed to USN as XR4D-8. Wright R-1820 engines uprated to 1425 hp.
Canadian Forces designation for the C-47 (post-1970)
One C-47 tested as a 40-seat troop glider with engines removed and faired over
USN/USMC version of the C-47
Twenty C-53Cs transferred to USN
C-47A variant 24-volt electrical system replacing the 12-volt of the C-47; redesignated C-47H in 1962, 238 transferred from USAF
R4D-5 for use in Antarctica. Redesignated LC-47H in 1962. Photos of this type show the removal of underslung engine oil coolers typical of the R-1830 engine installation; apparently not needed in the cold polar regions.
R4D-5 for use as special ECM trainer. Redesignated EC-47H in 1962
R4D-5 for use as a personnel transport for 21 passengers and as a trainer aircraft; redesignated TC-47H in 1962
R4D-5 for use as a special ASW trainer; redesignated SC-47H in 1962
R4D-5 for use as a VIP transport; redesignated VC-47H in 1962
USN R4D-8 from VR-23 Codfish Airline over Mount Fuji, 1952
United States Navy R4D-8
157 C-47Bs transferred to USN; redesignated C-47J in 1962
R4D-6L, Q, R, S, and Z
Variants as the R4D-5 series; redesignated LC-47J, EC-47J, TC-47J, SC-47J, and VC-47J respectively in 1962
44 TC-47Bs transferred from USAF for use as a navigational trainer; redesignated TC-47K in 1962
R4D-5 and R4D-6 remanufactured aircraft with stretched fuselage, Wright R-1820 engines, fitted with modified wings and redesigned tail surfaces; redesignated C-117D in 1962
R4D-8 converted for Antarctic use, redesignated LC-117D in 1962
R4D-8 converted as crew trainers, redesignated TC-117D in 1962
R4D-8 converted as a staff transport, redesignated VC-117D in 1962
RAF designation for nine C-53 Skytroopers received under the lend lease scheme. Unlike the majority of RAF Dakotas, these aircraft were therefore dedicated troop transports, lacking the wide cargo doors and reinforced floor of the C-47.
^ abO'Rourke, G.G, CAPT USN. "Of Hosenoses, Stoofs, and Lefthanded Spads". United States Naval Institute Proceedings, July 1968.
^C-47/R4D Skytrain units of the Pacific and CBI, David Isby, Osprey Combat Aircraft #66, Osprey Publishing Limited, 2007
^Air International out of Miami International Airport was a military depot used by the Air Force to convert the DC-3s into military use. They came in as commercial aircraft purchased from third world airlines and were completely stripped, rebuilt, and reconditioned. Long range fuel tanks were installed with upgraded avionics and gun mounts. They left as first rate military aircraft headed for combat in Vietnam in a variety of missions. "Chronological History of the EC-47's Location by Tail Number". ec47.com. Retrieved: 7 April 2009.
^Rickard, J. "Douglas EC-47N". historyofwar.org, 12 November 2008. Retrieved: 7 April 2009.