Two main types of transport aircraft were used during the war: large multiengine, land-based aircraft or flying boats designed to move many troops or supplies (some of these also served in bombing and reconnaissance roles); and assault or transport gliders designed to be towed, then released, so they could glide silently to a landing behind enemy lines.
The following are the most significant aircraft employed primarily for transport by both sides during World War II.
Designed originally in 1930 as a three-engine passenger carrier for Deutsche Lufthansa, the Junkers Ju-52/3m served as the primary transport aircraft of the German army in World War II. Including the approximately 200 civil models constructed prior to the war, a total of 4,800 Ju-52/3ms were built by the end of 1944. It made its military debut as a bomber and troop transport during the Spanish Civil War. Successive versions of the Ju-52/3m incorporated more-powerful engines that provided greater load capacity (approximately twice its empty weight of 12,600–14,300 lb) and interchangeable wheel, ski, or float landing gear that allowed it to operate in a variety of conditions. In addition to its transport duties, it served as a bomber, air ambulance, glider tug, and paratrooper transport.
Intended as a replacement for the Ju-52/3m, the Junkers Ju-252 Herkules relied on the same three-engine configuration as the Ju-52/3m but featured improved interior and exterior designs and more powerful engines, which not only made it faster and capable of bearing heavier loads but also gave it a range as much as twice that of the Ju-52/3m. Unfortunately for Germany, shortages of resources and manpower forced the Luftwaffe to limit production of the all-metal Ju-252 to just 15 aircraft. A mixed-wood and tube-steel version, the Ju-352 entered service in 1944, but it came too late in the war to make a difference. Just 45 of the Ju-352s were constructed.
Originally designed for Deutsche Lufthansa to serve as a trans-Atlantic flying boat, the six-engine Blohm und Voss Bv-222 Viking was the largest flying boat, and the largest aircraft of any kind, to serve in World War II. Although only 13 were produced, the Bv-222, which could carry up to 110 troops in addition to its 11-man crew, played an important role in transporting troops in the Mediterranean and North African Campaigns.
Germany employed three types of gliders as transports during World War II: the DFS-230, the Gotha Go-242, and the Messerschmitt Me-321 Gigant. Entering service in 1938, the DFS 230 could carry 8 airborne troops and proved to be the standard assault glider used by the Germany army during the war, with approximately 1,500 being constructed. Introduced in late 1941, the Gotha Go-242 could carry up to 23 airborne troops or the equivalent weight in supplies. As one of the largest aircraft of the war, the Messerschmitt Me-321 Gigant was capable of carrying up to 120 troops, 21,500 lb of freight, or 60 wounded soldiers. The Go-242 and Me-321 served primarily on the Eastern Front to bring food and supplies to German soldiers. Powered versions, the Go-244 and Me-323, were also developed for transport service.
Although the twin-engine Bristol Bombay was designed as a troop transport carrier in 1931, the economic conditions of the Great Depression delayed production until early 1939. While only 51 were produced, the Bristol Bombay, which was capable of carrying up to 24 troops or a payload of 7,200 lb, saw significant action for the Royal Air Force (RAF) during the first half of the war, ferrying troops and supplies across the English Channel in 1940, evacuating British forces from Crete in 1941, and dropping paratroopers behind enemy lines in North Africa.
Originally intended as a bomber, the Armstrong Whitworth Albemarle was instead converted to transport service. A total of 310 were used as transports for special operations, such as dropping paratroopers behind enemy lines. An additional 247 served as the standard tug for the Airspeed Horsa assault glider, seeing action in the invasion of Sicily in 1943 and the D day landings in June 1944. At least 10 were shipped to the Soviet Union.
Great Britain produced two primary transport gliders during the war: the Airspeed Horsa and the General Aircraft Hamilcar. The Horsa came in two varieties: the Mk.1, which was configured for carrying up to 25 troops; and the Mk.2, which could carry up to 7,000 lb of freight and featured a hinged nose section for easier loading and unloading. Approximately 3,800 of the Horsa gliders were constructed. The Hamilcar was the largest Allied glider of the war and was capable of carrying a payload of 17,500 lb. It first saw action in the D day landings and proved immensely significant because it could provide heavy equipment, such as the British Tetrarch Mk.IV tank, to airborne troops operating behind enemy lines.
Other British aircraft used in a transport role included those that also served as bombers or reconnaissance aircraft, such as the Handley Page Halifax, the Short Stirling, and Vickers Warwick.
Although Italy relied on several aircraft for transport duties, such as the Caproni CA 309-316, the Piaggio P.108, and the Savoia-Marchetti S.M.81 Pipistrello, their primary role was as bombers or reconnaissance aircraft. The Savoia-Marchetti S.M.75 and the Savoia-Marchetti S.M.82 Canguru were exceptions. The S.M.75 had originally been designed for passenger service for Ala Littoria in 1937. Requisitioned for military service when Italy entered the war in June 1940, the S.M.75 could carry up to 30 troops and saw action throughout the Mediterranean until the end of the war. A total of 98 were constructed. The three-engine S.M.82 proved to be one of the best heavy transports available to the Axis powers. It was capable of carrying up to 40 fully equipped troops or almost 9,000 lb of freight. Of approximately 400 S.M.82s constructed between 1941 and 1943, at least 50 entered service with the Luftwaffe in the Baltic area of the Eastern Front. Those that survived the war continued in service with the Italian air force into the 1950s.
Although Japan employed a variety of multipurpose aircraft, such as the Nakajima G5N Shinzan and the Tachikawa Ki-54, for transporting troops and supplies, it relied primarily on four main transport aircraft during World War II: the Kawanishi H6K flying boat, the Kawanishi H8K flying boat, the Kawasaki Ki-56, and the Mitsubishi Ki-57.
When Japan entered the war, the four-engine Kawanishi H6K served as the navy's primary long-range flying boat. Although used at first primarily for long-range reconnaissance, it was soon relegated to transport duty because of its vulnerability to Allied fighters. Capable of carrying up to 18 troops in addition to its crew, the H6K remained in production until 1943. Of the 217 constructed, 139 were designed exclusively for transport.
The four-engine Kawanishi H8K entered service in early 1942 and gradually replaced the Kawanishi H6K. While it also served in a variety of roles, its transport version, the H8K2-L, of which 36 were built, could carry up to 64 passengers. With a cruising speed of 185 mph and a range of up to 4,460 miles, it was well-suited for the Pacific Theater, and its heavy armament afforded better protection than the H6K.
Ironically, Japan's primary light transport aircraft, the twin-engine Kawasaki Ki-56, was a military version of a license-built American plane, the Lockheed 14 Electra. It was capable of carrying a payload of up to 5,290 lb or 14 passengers and had a range of approximately 3,300 miles. A total of 121 were constructed between 1941 and 1943.
Originally intended for passenger service with Nippon Koku KK, the twin-engine Mitsubishi Ki-57 was quickly adapted for service with both the Japanese army and navy beginning in 1940. After Japan entered the war, the original production series, of which 101 were built, was modified by adding more powerful engines. Between 1942 and early 1945, 406 of the new version (Ki-57-II) were constructed. These were capable of carrying a crew of 4 and up to 11 passengers or a cargo of approximately 7,000 lb to a range of up to 1,835 miles.
While the Soviet Union relied heavily on American aircraft, such as license-built Douglas C-47 Skytrains, for transport purposes, the four-engine Tupolev TB-3 (ANT-6), originally designed in the early 1930s as a heavy bomber, had been converted primarily for troop and freight transport by the time the Soviet Union entered World War II. Later versions fitted with four 1,200 hp engines were capable of carrying more than 12,000 lb of cargo. In addition to carrying airborne troops and supplies, it also served as a glider tug. Some were even modified to carry a tank or truck between their undercarriage legs.
Of all the powers in World War II, the United States had by far the largest number and variety of transport aircraft, in part because it was conducting simultaneous campaigns in the European and Pacific Theaters.
Without question, the twin-engine Douglas C-47 Skytrain was the most famous transport aircraft of World War II. As the DC-3, it had revolutionized civil air travel before the war. Once the United States entered the war, the Skytrain went into full-scale military production; 10,665 were produced by war's end, including 4,878 in 1944 alone. Of its variants, the C-47 Skytrain (known as the Dakota in British service), accounted for more than 9,000 of the total produced, approximately 1,800 of which were loaned to Great Britain through Lend-Lease. An additional 2,500 were constructed on license by the Soviet Union as the Lisunov Li-2. Even the Japanese built 485 as the Nakajima L2D through a 1938 license. With a range of 1,500 miles and capable of carrying 28 troops or a cargo of 10,000 lb, it saw service in every theater of the war.
The four-engine Consolidated Liberator Transport C-87 was a transport version of the Consolidated B-24 Liberator bomber. A total of 287 C-87s were produced and served with the U.S. Army Air Forces (USAAF) and the RAF as a transport and a tanker. As a transport, it was capable of carrying up to 25 passengers and up to 10,000 lb of freight. As a tanker, it could carry up to 2,400 gallons of fuel, which proved useful in a variety of theaters, but especially in support of Boeing B-29 Superfortresses operating in China.
Originally designed in 1936 as the CW-20 (a 36-passenger pressured airliner), the twin-engine Curtiss C-46 Commando entered service in 1942 after undergoing extensive modifications for military service. These included the installation of a large cargo door, a strengthened floor, and folding troop seats. It was capable of carrying up to 50 troops, 33 wounded soldiers, and up to 10,000 lb of cargo. These characteristics, combined with its excellent climbing ability, made it ideally suited for flying over the Himalayas ("the Hump") from India to China. A total of 3,341 were produced.
As with the Douglas C-47 Skytrain, the Douglas C-54 Skymaster was originally designed for passenger airliner service as the DC-4. After Pearl Harbor, the U.S. military quickly adopted it, with the first C-54 Skymaster entering service in February 1942. With a maximum range of 3,900 miles, Skymasters flew almost 80,000 trans-Atlantic flights during the course of the war with a loss of just three aircraft. It was capable of carrying 50 troops or 28,000 lb of cargo. It would remain in service until 1974 and is famous for its role in the Berlin Airlift of 1948.
The Waco CG-4A Hadrian proved to be one of the most effective transport gliders produced in the war. Designed for mass production, the Hadrian featured fabric-covered wooden wings and a steel tube fuselage, which was easily replicated by the 15 firms involved in constructing the 13,910 Hadrians produced during the war. Its most notable feature was a hinged nose section that raised upward and allowed cargo to be loaded directly into the cabin. It was capable of carrying 15 troops or 3,800 lb of cargo, which could include a jeep or 75 mm howitzer and its crew. It proved effective in landings in Sicily, the D day invasion, and the Rhine crossings, and it would have been an integral part of an Allied invasion of the Japanese mainland had the atomic bomb not ended the war.
Other successful U.S. transport aircraft of the war included the following three aircraft: the twin-engine Lockheed Lodestar, of which 625 were produced, was a military version of the civil Lockheed Model 14 Super Electra; the twin-engine Beechcraft C-45 Expeditor, of which 1,391 were built, was a military version of the civil Beechcraft Model 18 light transport; and the Martin PBM Mariner Flying Boat, of which 1,405 were produced, served in a variety of roles besides transport, including antisubmarine warfare, air-sea rescue, and maritime patrol. Justin D. Murphy
Jarrett, Philip, ed. Aircraft of the Second World War. London: Putnam, 1997.; Munson, Kenneth. Bombers, Patrol, and Transport Aircraft, 1939–45. Poole, UK: Blandford Press, 1975.; Wilson, Stewart. Aircraft of WWII. Fyshwick, Australia: Aerospace Publications, 1998.
Justin D. Murphy