C-47 Skytrain

1. Lead

The C-47 Skytrain was the most important transport aircraft of the Second World War and one of the most successful aircraft ever built. It was the military version of the Douglas DC-3, the airliner that had revolutionised civil aviation in the 1930s, adapted for war with a reinforced floor, a large cargo door, a hoist and a strengthened fuselage.

About 10,174 C-47s were built in the United States, and they served with the United States Army Air Forces, the Royal Air Force (where they were known as the Dakota) and many other air forces. They dropped paratroopers on D-Day and at Arnhem, towed gliders, flew supplies over the Himalayas on the “Hump” route to China, evacuated wounded, and carried everything from jeeps to artillery to whole divisions.

General Dwight D. Eisenhower named the C-47 as one of the four weapons that won the war for the Allies, alongside the bazooka, the jeep and the atomic bomb — a remarkable tribute to an unarmed transport aircraft.

The C-47 was never fast or glamorous. Its maximum speed was only about 360 km/h, it carried no guns and no bombs, and it was built from the same basic design as a civilian airliner. What it offered instead was reliability, versatility and numbers: it could take off from short, rough airstrips, it could carry 28 troops or 2,700 kg of cargo, it could be maintained in the field with basic tools, and it was available in the thousands, when the Allies needed it most.

It was, in the words of one historian, the aircraft that “held the Allied armies together”, because it was the link between the factories and the front lines, between the airfields and the battlefields, and between the paratroopers and the ground they had to take.

This article explains how the C-47 was developed, how it worked, what its variants were, how it served in combat, and why it remained in service for decades after the war.

2. Key Facts

Type	Twin-engined military transport
Country of origin	United States
Manufacturer	Douglas Aircraft Company / Douglas
First flight	23 December 1941 (C-47) / 23/12/1941
Years in service	1941–1970s (US service); in service elsewhere into the 1980s–2000s
Crew / Kíp lái	3–4 (pilot, co-pilot, navigator, radio operator)
Engines	2 × Pratt & Whitney R-1830-90C Twin Wasp radial, 1,200 hp each
Length	19.43 m (63 ft 9 in) / 19,43 m
Wingspan	29.11 m (95 ft 6 in) / 29,11 m
Height	5.18 m (17 ft) / 5,18 m
Maximum speed	About 360 km/h (224 mph)
Cruising speed	About 257 km/h (160 mph)
Range	About 2,575 km (1,600 mi)
Service ceiling	About 8,050 m (26,400 ft)
Payload	About 2,700 kg (6,000 lb) of cargo; or 28 troops; or 18 stretchers with 3 medical attendants
Armament	None (unarmed transport)
Production	About 10,174 (C-47 variants)
Users	United States, United Kingdom (as the Dakota), Canada, Australia, the Soviet Union (as the Li-2) and many others

3. Background

3.1. The DC-3 and the Birth of the C-47

The C-47 was born from the Douglas DC-3, the most successful airliner of the 1930s. The DC-3, designed by Donald Douglas and first flown in 1935, was a twin-engined, low-wing monoplane that could carry 21 passengers in comfort, fly at about 300 km/h, and operate from short, unpaved airstrips.

It was the first airliner that could make a profit carrying passengers alone, without mail subsidies, and it became the standard airliner of the world, with more than 600 built before the war. When the United States entered the Second World War, the Army Air Forces needed a transport aircraft in large numbers, and the DC-3 was the obvious choice: it was already in production, it was reliable, and it could be adapted for military use with relatively small changes.

The military version, designated the C-47, was fitted with a reinforced floor, a large cargo door on the left side, a hoist for loading heavy equipment, and a strengthened fuselage, and it was first flown on 23 December 1941, only two weeks after the attack on Pearl Harbor.

3.2. The Need for Air Transport

The Second World War was the first war in which air transport was essential. Armies moved faster and further than ever before, and they needed to be supplied by air when roads and railways were cut or did not exist. Paratroopers needed aircraft to drop them behind enemy lines, glider troops needed aircraft to tow them, and wounded men needed aircraft to evacuate them to hospitals.

The C-47 was the aircraft that met all of these needs: it could carry troops, cargo, gliders and casualties, it could operate from rough airstrips close to the front, and it could be produced in the thousands. The American aircraft industry, which built more than 300,000 aircraft during the war, made the C-47 one of its priorities, and the Douglas factories in California and Oklahoma, together with plants in other states, produced C-47s at a rate of hundreds per month.

The C-47 was not the only Allied transport — the British had the Armstrong Whitworth Albemarle and the Americans had the Curtiss C-46 Commando — but it was the most numerous, the most reliable and the most versatile, and it became the standard transport of the Allied armies.

4. Design and Development

4.1. From Airliner to Military Transport

The C-47’s design was a direct adaptation of the DC-3, and its success was due to the soundness of the original design. The DC-3 was a low-wing monoplane with a semi-monocoque fuselage, a retractable tailwheel undercarriage and two Pratt & Whitney R-1830 Twin Wasp radial engines, each producing 1,200 hp.

The C-47 kept the DC-3’s wing, engines and tail, but it changed the fuselage: the floor was reinforced to carry heavy cargo, a large cargo door, 1.8 metres wide and 1.5 metres high, was cut into the left side, a hoist was fitted above the door, and the cabin was fitted with folding seats for 28 troops, or with racks for 18 stretchers.

The C-47 also had a strengthened fuselage, to withstand the stresses of paratroop drops and glider towing, and it had a navigator’s astrodome, a radio operator’s station and a cargo-loading system. The changes were practical and modest, and they turned a comfortable airliner into a rugged military transport without changing the aircraft’s basic flying qualities.

4.1.1. The Cargo Door and the Paratroop Role

The C-47’s large cargo door was its most important military feature, and it was the key to the aircraft’s versatility. The door was wide enough to load a jeep, a 75mm pack howitzer, or a pallet of supplies, and it was fitted with a hoist that could lift heavy equipment into the cabin.

The door was also the paratroopers’ exit: on D-Day and at Arnhem, paratroopers jumped from the C-47’s door, in sticks of 18 men, and the aircraft’s low speed and stable flight made the drop as safe as it could be.

The C-47’s door was on the left side of the fuselage, which meant that the paratroopers jumped into the slipstream on the left, away from the tail, and the aircraft’s jumpmaster, who stood in the door, could see the drop zone and signal the men to jump.

The cargo door was a simple feature, but it was the feature that made the C-47 a military aircraft, rather than an airliner in uniform.

4.2. Engines, Performance and Handling

The C-47 was powered by two Pratt & Whitney R-1830-90C Twin Wasp radial engines, each producing 1,200 hp, which gave the aircraft a maximum speed of about 360 km/h and a cruising speed of about 257 km/h. The engines were reliable and easy to maintain, and the C-47 could fly on one engine if the other failed, which was essential for an aircraft that often flew over enemy territory or over the sea.

The aircraft’s range was about 2,575 km, which was enough to fly from England to Normandy and back, or from India over the Himalayas to China, and its service ceiling was about 8,050 metres, which was high enough to fly over most mountains, although the “Hump” route over the Himalayas required the aircraft to fly at its ceiling, in thin air and in terrible weather.

The C-47’s handling was gentle and forgiving: it was a stable, comfortable aircraft to fly, and it could take off from short, rough airstrips, which was essential for an aircraft that often operated from forward airfields close to the front.

4.3. Variants: C-47, C-53, Dakota and Li-2

The C-47 was built in a number of variants. The C-47 was the standard cargo version, with a large cargo door and a reinforced floor. The C-53 Skytrooper was a troop-carrying version, without the cargo door, built for paratroop operations, and about 380 were built. The C-47A and C-47B were improved versions, with more powerful engines and better electrical systems, and they were the most numerous variants.

The Royal Air Force called the C-47 the Dakota, and the RAF’s Dakotas served in every theatre, from Normandy to Burma. The Soviet Union built the DC-3 under licence as the Lisunov Li-2, and about 6,000 Li-2s were built, serving as transports, bombers and paratroop aircraft.

The C-47 was also built as the R4D by the US Navy, and as the AC-47 gunship in Vietnam, where the transport was fitted with side-firing machine guns. The C-47’s family was one of the largest of any aircraft, and it shows the versatility of the original DC-3 design.

5. Technical Specifications

5.1. Performance

The C-47’s performance figures tell the story of an aircraft built for reliability rather than speed. Its maximum speed of about 360 km/h was slow for a wartime aircraft — a B-17 Flying Fortress could fly at more than 460 km/h — but the C-47’s cruising speed of about 257 km/h was economical, and at that speed it could fly for more than 10 hours.

Its range of about 2,575 km was enough for most of the missions it was asked to fly, and with overload fuel tanks it could fly further. Its service ceiling of about 8,050 metres was high for a transport, and it allowed the C-47 to fly over the Himalayas on the “Hump” route, although the route required the aircraft to fly at its ceiling, in icing conditions and in violent turbulence.

The C-47’s rate of climb was slow, and it took a long time to reach altitude, but once it was airborne it was a stable, comfortable platform, and its crew could work in shifts during a long flight. The C-47’s performance was not spectacular, but it was enough, and it was the performance that the Allies needed.

5.1.1. Flying the Hump

The “Hump” was the air route from India over the Himalayas to China, and it was one of the most dangerous air routes of the war. The C-47s that flew the Hump had to cross mountains more than 5,000 metres high, in weather that could change in minutes, with icing, turbulence and winds that could blow an aircraft off course.

The route was flown day and night, in all weathers, because China needed supplies to continue fighting Japan, and the C-47 was the aircraft that flew most of the Hump missions. The losses were heavy: more than 500 aircraft were lost on the Hump, and more than 1,500 airmen were killed, but the C-47s kept flying, and by the end of the war they had delivered more than 650,000 tons of supplies to China.

The Hump was the C-47’s hardest test, and it proved that the aircraft could fly in the worst conditions in the world and keep flying.

5.2. Load, Crew and Reliability

The C-47 could carry about 2,700 kg of cargo, or 28 fully equipped troops, or 18 stretchers with three medical attendants, and it could also tow a glider, such as the Waco CG-4A, which carried 13 troops or a jeep.

The aircraft’s crew was three to four men — a pilot, a co-pilot, a navigator and a radio operator — and they worked in a cockpit that was comfortable and well laid out, with good visibility and with instruments that were easy to read.

The C-47’s reliability was legendary: the Pratt & Whitney engines were dependable, the airframe was rugged, and the aircraft could be maintained in the field with basic tools. The C-47 could take off from short, rough airstrips, it could operate in dust, mud and snow, and it could be repaired with parts that were available anywhere in the world, because the DC-3 had been built in such large numbers.

The C-47’s reliability was its greatest asset, and it was the reason that the Allies trusted it with their most important missions.

6. Variants

6.1. The Main Production Versions

The C-47 was built in a long series of versions, from the original C-47 of 1941 to the C-47B of 1944, which had more powerful engines and a better electrical system for high-altitude operations. The C-47A, the most numerous version, was built in about 5,000 examples, and it was the standard transport of the US Army Air Forces.

The C-53 Skytrooper, built in about 380 examples, was a troop-carrying version without the cargo door, designed for paratroop operations. The R4D was the US Navy’s version, used for transport and for air-sea rescue, and the Dakota was the Royal Air Force’s name for the C-47, used in every theatre.

The Soviet Li-2, built under licence, was used as a transport, a bomber and a paratroop aircraft, and it was the most numerous Soviet transport of the war. The C-47’s production total of about 10,174, together with the DC-3’s civil production and the Li-2’s 6,000, made the DC-3 family one of the largest aircraft families in history, with more than 16,000 built in total.

6.1.1. The AC-47 Gunship in Vietnam

The C-47’s most famous post-war variant was the AC-47 gunship, developed in Vietnam in the 1960s. The AC-47, nicknamed “Puff the Magic Dragon” and “Spooky”, was a C-47 fitted with three side-firing 7.62mm Miniguns, which could fire thousands of rounds per minute at targets on the ground while the aircraft circled overhead.

The AC-47 was used to defend isolated outposts, to support ground troops at night, and to attack Viet Cong concentrations, and it was highly effective: a single AC-47 could put more firepower onto a target than a whole infantry company. The AC-47’s success led to the development of larger gunships, the AC-119 and the AC-130, which remain in service today.

The AC-47 showed the C-47’s versatility: an aircraft designed as a transport in the 1930s could be adapted, thirty years later, into a gunship, and it could still be effective in a very different war. The AC-47 was crewed by seven men, including three gunners who operated the Miniguns, and it flew at night, circling its target and firing in long bursts that could be seen for miles across the dark jungle.

6.2. The Dakota and the Li-2

The C-47’s service with the Royal Air Force, as the Dakota, and with the Soviet Union, as the Li-2, shows the aircraft’s international importance. The RAF’s Dakotas served in Normandy, where they dropped paratroopers on D-Day and towed gliders, in Burma, where they supplied the Chindits and the Fourteenth Army, and in the Berlin Airlift, where they carried supplies into the blockaded city.

The Soviet Li-2, built under licence by Lisunov, served as a transport, a bomber and a paratroop aircraft, and it was the aircraft that carried Soviet paratroopers and supplies throughout the war. The Dakota and the Li-2 were the same basic aircraft as the C-47, but they served in different air forces, in different theatres, and they show that the DC-3 design was a universal one, capable of serving any air force, in any role, in any part of the world.

7. Combat Service

7.1. D-Day, Market Garden and the Airborne Operations

The C-47’s most famous missions were the airborne operations of the Second World War. On the night of 5–6 June 1944, more than 800 C-47s dropped about 13,000 American paratroopers of the 82nd and 101st Airborne Divisions behind the beaches of Normandy, in the opening hours of D-Day.

The drops were scattered by flak and by bad weather, and many paratroopers landed far from their drop zones, but the airborne troops fought their way to their objectives and played a crucial role in the invasion. The C-47s also towed gliders carrying troops, jeeps and artillery, and they flew resupply missions to the airborne troops in the days after the landing.

In September 1944, C-47s dropped paratroopers and towed gliders in Operation Market Garden, the Allied attempt to seize the bridges over the Rhine at Arnhem, and in March 1945 they dropped paratroopers in Operation Varsity, the crossing of the Rhine.

The C-47 was the aircraft that made the Allied airborne operations possible, and its crews, who flew unarmed, at low level, through flak, were among the bravest airmen of the war.

7.1.1. The Glider Towing Role

The C-47’s role as a glider tug was almost as important as its role as a paratroop transport. The Waco CG-4A glider, which the C-47 towed, could carry 13 troops or a jeep or a 75mm howitzer, and it was used to deliver heavy equipment that paratroopers could not carry.

The C-47 towed the glider on a long rope, at about 200 km/h, and released it over the landing zone, where the glider pilot landed it on a field or a road. Glider landings were dangerous — many gliders crashed on landing, and the troops they carried were often injured — but they were the only way to deliver heavy equipment to airborne troops, and the C-47’s ability to tow gliders was essential to the airborne operations.

The C-47’s glider-towing role was a reminder of the aircraft’s versatility: it could drop paratroopers, tow gliders, carry cargo and evacuate wounded, all in the same day, and it could do so from rough airstrips close to the front.

7.2. The Hump, the Berlin Airlift and the Pacific

The C-47’s service was not limited to the airborne operations. In the China-Burma-India theatre, C-47s flew the “Hump” route over the Himalayas, delivering more than 650,000 tons of supplies to China, and they also supplied the Chindits, the British long-range penetration force in Burma, dropping supplies to troops operating behind Japanese lines.

In the Pacific, C-47s supplied the American troops who fought in New Guinea, the Philippines and Okinawa, flying from rough airstrips in the jungle and evacuating wounded. After the war, C-47s played a crucial role in the Berlin Airlift of 1948–49, when the Soviet Union blockaded Berlin and the Allies supplied the city by air.

C-47s, together with larger aircraft, flew thousands of sorties into Berlin, carrying food, fuel and medicine, and they helped to keep the city alive until the blockade was lifted. The C-47’s service in the Berlin Airlift was its last great mission, and it showed that the aircraft was still essential, even in peacetime — the Airlift itself took place after the war, in 1948–49.

8. Strengths and Weaknesses

8.1. Reliability, Versatility and Numbers

The C-47’s greatest strength was its reliability. The Pratt & Whitney engines were dependable, the airframe was rugged, and the aircraft could be maintained in the field with basic tools, which was essential for an aircraft that operated from forward airfields close to the front.

Its second strength was its versatility: the C-47 could carry troops, cargo, gliders and casualties, it could drop paratroopers, tow gliders, and fly in any weather, and it could be adapted to almost any role. Its third strength was its numbers: about 10,174 were built, more than any other Allied transport, and the C-47 was available in the thousands, when the Allies needed it most.

Its fourth strength was its ability to operate from short, rough airstrips, which allowed it to fly close to the front and to deliver supplies where they were needed most. These strengths made the C-47 the most important transport aircraft of the war, and it was the aircraft that the Allies turned to whenever they needed to move men or supplies by air.

8.2. Slow Speed, No Armament and Vulnerability

The C-47’s weaknesses were the price of its design as a transport. Its maximum speed of about 360 km/h made it an easy target for enemy fighters, and C-47s that were caught by German or Japanese fighters had little chance of escape — they were too slow to run and they carried no guns to fight back.

The aircraft was unarmed, and it relied on fighter escort and on flying at night or at low level to avoid interception. The C-47 was also vulnerable to flak, especially during paratroop drops, when it had to fly straight and level at low altitude over the drop zone, and many C-47s were lost to anti-aircraft fire on D-Day and at Arnhem.

The aircraft’s range, at about 2,575 km, was adequate for most missions, but it was not enough for the longest routes, and the C-47 needed to refuel frequently. These weaknesses did not prevent the C-47 from being an effective transport, but they meant that it had to be used with fighter protection, and that its crews accepted a high level of risk.

9. Comparison with Rivals

9.1. Against the C-46 Commando and the Ju 52

The C-47’s closest American rival was the Curtiss C-46 Commando, a larger transport that could carry more cargo and fly further than the C-47, and that was used on the “Hump” route, where its greater range and payload were valuable.

But the C-46 was more expensive, more complex and less reliable than the C-47, and it was produced in smaller numbers — about 3,100, against the C-47’s 10,174 — and it was not as versatile as the C-47, because it could not operate from as short airstrips.

The German Junkers Ju 52 was the C-47’s German counterpart: a three-engined transport that was the workhorse of the Luftwaffe, used to drop paratroopers in Crete and to supply the German army at Stalingrad. The Ju 52 was slower than the C-47, at about 290 km/h, and it carried fewer troops, but it was rugged and reliable, and it was the aircraft that the German army relied on.

The C-47’s advantage was that it was faster, carried more, and was available in far larger numbers, and it was the aircraft that the Allies had when they needed it most.

9.2. Against the Post-War Transports

The C-47 was also compared with the post-war transports that replaced it, such as the Fairchild C-119 Flying Boxcar and the Lockheed C-130 Hercules. The C-119 could carry more cargo and had a rear loading ramp, which made it easier to load, and the C-130 was faster, larger and more capable in every way.

But the C-47 remained in service long after the C-119 had been retired, and it was still flying in the 1970s and 1980s, because it was reliable, cheap to operate and easy to maintain, and because it could operate from airstrips that larger aircraft could not use.

The C-130 eventually replaced the C-47 as the standard Allied transport, but the C-47’s long career — more than thirty years in front-line service — is a testament to the soundness of its design. The C-47 was not the most capable transport, but it was the transport that was available, in the numbers needed, when it mattered most.

10. Legacy

10.1. The Aircraft That Won the War

The C-47’s most lasting legacy is Eisenhower’s tribute: that it was one of the four weapons that won the war for the Allies. The C-47 was the aircraft that dropped the paratroopers on D-Day, that flew the supplies over the Hump, that towed the gliders at Arnhem, and that supplied the armies that liberated Europe and the Pacific.

Without the C-47, the Allied airborne operations would have been impossible, the supply of China would have been impossible, and the advance of the Allied armies would have been far slower. The C-47’s legacy is therefore a strategic one: it showed that air transport was not a luxury, but a necessity, and that the army that could move men and supplies by air had a decisive advantage.

The C-47’s concept — the military transport, based on a civilian airliner, produced in large numbers — has shaped military aviation ever since, and the modern military transport, from the C-130 to the A400M, is the direct descendant of the C-47.

10.2. The DC-3 Still Flying

Today, the DC-3 and the C-47 are still flying, more than eighty years after the DC-3 first flew. About 200 DC-3s and C-47s are still in service around the world, carrying cargo in remote areas, flying tourists, and serving as warbirds at airshows.

The aircraft’s longevity is a testament to its design: the DC-3 was so well built that it has outlasted almost every other aircraft of its era, and it remains a practical, economical aircraft for operations in remote areas. The C-47 is preserved in museums around the world, from the National WWII Museum in New Orleans to the Imperial War Museum in Duxford, and it is the subject of many books, films and documentaries.

The C-47’s place in history is secure: it was not a glamorous aircraft, but it was an essential one, and it did the unglamorous, vital work of moving men and supplies, and of bringing paratroopers to the battle and wounded men home.

11. Frequently Asked Questions

What is the difference between the C-47 and the DC-3?
The C-47 was the military version of the DC-3 airliner, with a reinforced floor, a large cargo door, a hoist and a strengthened fuselage. The DC-3 was a civilian airliner; the C-47 was a military transport.

How many C-47s were built?
About 10,174 C-47 variants were built in the United States, together with about 6,000 Soviet Li-2s built under licence, making the DC-3 family one of the largest aircraft families in history.

What did the British call the C-47?
The Dakota. The Royal Air Force’s Dakotas served in Normandy, Burma and the Berlin Airlift.

Did the C-47 drop paratroopers on D-Day?
Yes. On the night of 5–6 June 1944, more than 800 C-47s dropped about 13,000 American paratroopers of the 82nd and 101st Airborne Divisions behind the Normandy beaches.

What was the Hump?
The air route from India over the Himalayas to China, flown by C-47s to deliver supplies to China. More than 650,000 tons of supplies were delivered, at the cost of more than 500 aircraft and 1,500 airmen.

Are any C-47s still flying?
Yes. About 200 DC-3s and C-47s are still flying around the world, carrying cargo in remote areas and serving as warbirds at airshows.

12. Sources

1. Wikipedia, “Douglas C-47 Skytrain” — first flight 23 December 1941, production of about 10,174, specifications (19.43 m, 29.11 m, 360 km/h, 2,575 km, 2,700 kg).
2. Wikipedia, “Douglas DC-3” — the DC-3 airliner, first flight 1935, and its adaptation as the C-47.
3. National WWII Museum, New Orleans — the C-47 on D-Day, Operation Market Garden and the Berlin Airlift.
4. Imperial War Museum, Duxford — the Dakota in RAF service, Normandy and Burma.
5. Dwight D. Eisenhower, Crusade in Europe — Eisenhower’s tribute to the C-47 as one of the four weapons that won the war.
6. Smithsonian National Air and Space Museum — the C-47, the Hump route and the Berlin Airlift.

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