<p>The word 'ubiquitous' has been associated with a number of aircraft in widescale use during World War II, but the most ubiquitous of all has to be the Douglas C-47/C-53/R4D/Skytrain/Skytrooper Dakota/'Gooney Bird'. Use any name you like for this superlative wartime transport aircraft, produced in greater numbers than any other in this category, with almost 11,000 manufactured by the time production ended in 1945. Whatever name you choose, it can be spelled 'dependable', for this was the secret of the type's greatness and enduring service life.
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<p>Its design originated from the DC-2/DST/DC-3 family of commercial transports that followed in the wake of the DC-1 prototype that flew for the first time on 1 July 1933. The US Army had gained early experience of the basic aircraft after the acquisition of production DC-2s in 1936, followed by more specialized conversions for use as cargo and personnel transports. In August 1936 the improved DC-3 began to enter service with US domestic airlines, its larger capacity and enhanced performance making it an even more attractive proposition to the US Army, which very soon advised Douglas of the changes in configuration which were considered desirable to make it suited for operation in a variety of military roles. These included the provision of more powerful engines, a strengthened rear fuselage to cater for the inclusion of large cargo doors, and reinforcement of the cabin floor to make it suitable for heavy cargo loads. Much of the basic design work had already been completed by Douglas, for a C-41 cargo prototype had been developed by the installation of 1,200-hp (895-kW) Pratt & Whitney Twin Wasp engines in a C-39 (DC-2) fuselage. In 1940, when the US Army began to issue contracts for the supply of these new transport aircraft under the designation C-47, the company was well prepared to meet the requirements and to get production under way . The only serious problem was lack of productive capacity at Santa Monica, where European demands for the DB-7 light bomber had already filled the factory floor, resulting in the C-47 being built in a new plant at Long Beach, California.
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<p>Initial production version was the C-47, of which 953 were built at Long Beach, and since the basic structural design remained virtually unchanged throughout the entire production run, this version will serve for a description of the structure and powerplant. Of all-metal light alloy construction, the cantilever monoplane wing was set low on the fuselage, and was provided with hydraulically operated split-type trailing-edge flaps; the ailerons comprised light alloy frames with fabric covering. The fuselage was almost circular in cross-section. The tail unit was conventional but, like the ailerons, the rudder and elevators were fabric-covered. Pneumatic de-icing boots were provided on the leading edges of wings, fin and tailplane. Landing gear comprised semi-retractable main units which were raised forward and upward to be housed in the upper half of the engine nacelles, with almost half of the main wheels exposed. The powerplant of the C-47 comprised two Pratt & Whitney R-1830-92 Twin Wasp engines, supercharged to provide an output of 1,050 hp (783 kW) at 7,500 ft (2,285 m), and each driving a three-bladed constant-speed metal propeller. The crew consisted of a pilot and co-pilot/navigator situated in a forward compartment, with the third member, the radio operator, in a separate compartment.
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<p>The all-important cabin could be equipped for a variety of roles. For the basic cargo configuration, with a maximum load of 6,000 lb (2,722 kg), pulley blocks were provided for cargo handling and tie-down rings to secure it in flight. Alternative layouts could provide for the transport of 28 fully-armed paratroops, accommodated in folding bucket-type seats along the sides of the cabin, or for 18 stretchers and a medical team of three. Racks and release mechanism for up to six parachute pack containers could be mounted beneath the fuselage, and there were also underfuselage mountings for the transport of two three-bladed propellers.
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<p>The first C-47s began to equip the USAAF in 1941, but initially these were received only slowly and in small numbers, as a result of the establishment of the new production line at Long Beach which, like any other, needed time to settle down to routine manufacture. With US involvement in World War II in December 1941, attempts were made to boost production, but in order to increase the number of aircraft in service as quickly as possible DC-3s already operating with US airlines, or well advanced in construction for delivery to operators, were impressed for service with the USAAF.
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<p>As Douglas began to accumulate contracts calling for production of C-47s in thousands, it was soon obvious that the production line at Long Beach would be quite incapable of meeting requirements on such a large scale, so a second production line was established at Tulsa, Oklahoma. The first model to be built at Tulsa was the second production version, the C-47A, which differed from the C-47 primarily by the provision of a 24-volt, in place of a 12-volt, electrical system. Tulsa was to build 2,099 and Long Beach 2,832 of the type, 962 of them being delivered to the RAF which designated them Dakota IIIs. Last of the major production variants was the C-47B, which was provided with R-1830-90 or -90B engines that had two-stage superchargers to offer high-altitude military ratings of 1,050 hp (783 kW) at 13,100 ft (3,990 m) or 900 hp (671 kW) at 17,400 ft (5,305 m), respectively. These were required for operation in the China-Burma-India (CBI) theater, in particular for the 'Hump' operations over the 16,500-ft (5,030-m) high Himalayan peaks, carrying desperately needed supplies from bases in India to China. Long Beach built only 300 of the model, but Tulsa provided 2,808 C-47Bs plus 133 TC-47Bs which were equipped for service as navigational trainers. The UK received a total of 896 C-47Bs, which in RAF service were designated Dakota IV.
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<p>The availability of such large numbers, in both US and British service, meant that it was possible to begin to utilize the C-47s on a far more extensive basis. The formation in mid-1942 of the USAAF's Air Transport Command saw the C-47s' wide-scale deployment as cargo transports, carrying an almost unbelievable variety of supplies into airfields and airstrips which would have been complimented by the description 'primitive'. Not only were the C-47s carrying in men and materials, but they were soon involved in a two-way traffic, serving in a casualty-evacuation role as they returned to their bases. These were the three primary missions for which these aircraft had been intended when first procured: cargo, casualty evacuation, and personnel transports.
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<p>However, their employment by the USAAF's Troop Carrier Command from mid-1942, and the RAF's Transport Command, was to provide two new roles, arguably the most important of their deployment in World War II, as carriers of airborne troops. The first major usage in this capacity came with the invasion of Sicily in July 1943, when C-47s dropped something approaching 4,000 paratroops. RAF Dakotas of Nos 31 and 194 Squadrons were highly active in the support of Brigadier Orde Wingate's Chindits, who infiltrated the Japanese lines in Burma in an effort to halt their advance during the winter of 1942-43, their only means of supply being from the air. Wingate (by then a major general) died on 24 March 1944 when a Dakota in which he was a passenger crashed into cloud-camouflaged jungle-clad mountains.
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<p>The other important role originated with the C-53 Skytrooper version, built in comparatively small numbers as the C-53B/-53C/-53D; seven C-53s supplied to the RAF were redesignated Dakota II. These were more nearly akin to the original DC-3 civil transport, without a reinforced floor or double door for cargo, and the majority had fixed metal seats to accommodate 28 fully-equipped paratroops. More importantly, they were provided with a towing cleat so that they could serve as a glider tug, a feature soon to become standard with all C-47s, and it is in this capacity that they served conspicuously in both USAAF and RAF service during such operations as the first airborne invasion of Burma on 5 March 1944 and the D-Day invasion of Normandy some three months later. In this latter operation more than 1,000 Allied C-47s were involved, carrying paratroops and towing gliders laden with paratroops and supplies. In the initial stage of this invasion 17,262 US paratroops of the 82nd and 101st Airborne Divisions and 7,162 men of the British 6th Airborne Division were carried across the English Channel in the greatest airlift of assault forces up to that time. Not all, of course, were carried in or towed by C-47s, but these aircraft played a very significant role in helping to secure this first vital foothold on European soil: in fewer than 60 hours, C-47s alone airlifted more than 60,000 paratroops and their equipment to Normandy.
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<p>Other C-47 variants of World War II included the XC-47C, prototype of a projected version to be equipped as a floatplane or, as was the prototype, with convertible amphibious floats. Of all-metal construction, these single-step Edo floats each had two retractable wheels, and housed a 300-US gal (1,136-liter) fuel tank. While this version was not built as such by Douglas, a small number of similar conversions were made by USAAF maintenance units for service in the Pacific. Douglas was also contracted to build 131 staff transports under the designation C-117, these having the airline-standard cabin equipment of a commercial DC-3, plus the improvements which were current on the C-47. Their numbers, however, had reached only 17 (one C-117B built at Long Beach and 16 C-117As from Tulsa) when VJ-Day brought contract cancellation. The requirement for a large-capacity high-speed transport glider, to be towed by a C-54, resulted in experimental conversion of a C-47 to serve in this role under the designation XCG-17. Early tests had been conducted with a C-47 making unpowered approaches and landings to confirm the feasibility of the project, followed by a series of flights in which one C-47 was towed by another: for take-off the towed aircraft used some power, but shut down its engines when airborne. Conversion of a C-47 to XCG-17 configuration began after completion of these tests, with engines, propellers and all unnecessary equipment removed, and the forward end of the engine nacelles faired over. This was undoubtedly aerodynamically inefficient, and contributed to a reduction in performance of the XCG-17, but it was a USAAF requirement that any production aircraft should be capable of easy reconversion to powered C-47s. Despite any inefficiency, the embryo cargo glider had a successful test program, demonstrating a towed speed of 290 mph (467 km/h), stalling speed of only 35 mph (56 km/h) and a glide ratio of 14:1. Payload was 14,000 lb (6,350 kg), permitting the transport of 40 armed paratroops. No production aircraft were built, however, as a result of changing requirements.
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<p>In addition to the C-47s which served with the USAAF and RAF, approximately 600 were used by the US Navy. These comprised the R4D-1 (C-47), R4D-3 (C-53), R4D-4 (C-53C), R4D-5 (C-47A), R4D-6 (C-47B) and R4D-7 (TC-47B). US Navy and US Marine Corps requirements resulted in several conversions with designations which include the R4D-5E/-6E with special-purpose electronic equipment; the winterized and usually ski-equipped R4D-5L/-6L; the R4D-4Q/-SQ/-6Q for radar countermeasures; cargo versions reequipped for passenger carrying as the R4D-5R/-6R; the air-sea warfare training R4D-5S/-6S; the navigational training R4D-5T/-6T; and the VIP-carrying R4D-5Z/-6Z. R4Ds were used initially by the Naval Air Transport Service that was established within five days of the attack on Pearl Harbor, equipping its VR-1, VR-2 and VR-3 squadrons, and soon after this by the South Pacific Combat Air Transport Service which provided essential supplies to US Marine Corps units as they forced the Japanese to vacate islands which stretched across the seas and led like stepping stones to that nation's home islands.
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<p>In addition to US production, the type was built in the USSR as the Lisunov Li-2 (2,000 examples or more) and in Japan as the Showa (Nakajima) L2D (485 examples).
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<p>C-47s had been involved from the beginning to the end of World War II, and that is but a small portion of their history in both military and civil service. Since VJ-Day, military C-47s have supported the Berlin Airlift, Korean and Vietnam Wars. In the latter the type performed special missions in the form of the AC-47D gunship, with three Miniguns mounted in the port side of the rear fuselage, and the EC-47 for psychological warfare and electronic reconnaissance.
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<hi style=hdr1>Specification</hi>
<list style=aflst>
<item><hi format=bold>Type:</hi> military transport and glider tug
<item><hi format=bold>Powerplant (C-47A):</hi> two 1,200-hp (895-kW) Pratt & Whitney R-1830-93 Twin Wasp radial piston engines
<item><hi format=bold>Performance:</hi> maximum speed 229 mph (369 km/h) at 7,500 ft (2,285 m); cruising speed 185 mph (298 km/h) at 10,000 ft (3,050 m); service ceiling 23,200 ft (7,070 m); range 1,500 miles (2,414 km)
<item><hi format=bold>Weights:</hi> empty 16,970 lb (7,698 kg); maximum take-off 26,000 lb (11,793 kg)
<item><hi format=bold>Dimensions:</hi> span 95 ft 0 in (28.96 m); length 64 ft 2 in (19.57 m); height 16 ft 11 in (5.16 m); wing area 987 sq ft (91.69 m<su>2</su>)
