Historic Aircraft: The Douglas DC-3

The Douglas DC-3 and its military counterpart, the C-47 Skytrain, hold a special place in aviation history as one of the most iconic aircraft of all time. For 32 years, Philippine Airlines had the privilege of utilizing this legendary aircraft.

The Douglas DC-3 had a lasting impact on the airline industry in the 1930s to 1940s and World War II. Developed as a larger, improved version of the DC-2, the DC-3 had exceptional qualities compared to previous aircraft. It was fast, had a good range, was more reliable, and carried passengers in greater comfort.

The low-wing metal monoplane with conventional landing gear was powered by two radial piston engines of 1,000–1,200 hp (750–890 kW). The DC-3 had a cruising speed of 207 mph (333 km/h), a capacity of 21 to 32 passengers or 6,000 lbs (2,700 kg) of cargo, and a range of 1,500 mi (2,400 km), and could operate from short runways.

Before the war, the DC-3 pioneered many air travel routes. It was able to cross the continental United States from New York to Los Angeles in 18 hours, with only three stops. It was one of the first airliners that could profitably carry only passengers without relying on mail subsidies.

The DC-3’s design proved adaptable and useful on less commercially demanding routes, even after the war when the airliner market was flooded with surplus transport aircraft. Civilian DC-3 production ended in 1942 at 607 aircraft. Military versions, including the C-47 Skytrain (the Dakota in British RAF service), and Soviet- and Japanese-built versions, brought total production to over 16,000.

Even today, many DC-3s and military derivatives are still flying. In 2013, it was estimated that 2,000 DC-3s and military derivatives were still in use, while a 2017 article put the number at more than 300. The Douglas DC-3 will always hold a special place in aviation history for its significant contributions to the industry.

History of the DC-3

The development of the DC-3 began after an inquiry from Transcontinental and Western Airlines (TWA) to Donald Douglas, who had designed the 1933 DC-1 and the DC-2 in 1934, which was a success but had room for improvement. The DC-3 resulted from a telephone call from American Airlines CEO C. R. Smith to Donald Douglas, who persuaded a reluctant Douglas to design a sleeper aircraft based on the DC-2 to replace American’s Curtiss Condor II biplanes. The new aircraft was engineered by a team led by chief engineer Arthur E. Raymond over the next two years.

The prototype DST (Douglas Sleeper Transport) first flew on December 17, 1935, and was followed by the DC-3 built for delivery to American Airlines. The cabin of the DC-3 was 92 inches (2,300 mm) wide, and a version with 21 seats instead of the 14–16 sleeping berths of the DST was given the designation DC-3. The DC-3 and DST popularized air travel in the United States, as transcontinental flights could cross the U.S. in about 15 hours with three refueling stops.

The DC-3 had several radial engines available, with early-production civilian aircraft using either the 9-cylinder Wright R-1820 Cyclone 9 or the 14-cylinder Pratt & Whitney R-1830 Twin Wasp. The Twin Wasp was chosen for most military versions and was also used by most DC-3s converted from military service. Five DC-3S Super DC-3s with Pratt & Whitney R-2000 Twin Wasps were built in the late 1940s, three of which entered airline service.

The Douglas DC-3, with a production number of 16,079, is one of the most iconic aircraft of all time. It is a propeller-driven airliner that was manufactured by Douglas Aircraft Company in the 1930s to 1940s and World War II. Its development was a result of an inquiry from Transcontinental and Western Airlines (TWA) to Donald Douglas, who designed and built an aircraft that would allow TWA to compete with United Airlines. Its cabin was 92 in (2,300 mm) wide, and a version with 21 seats instead of the 14–16 sleeping berths of the DST was given the designation DC-3.

The DC-3 popularized air travel in the United States and played a significant role in World War II. The military variants C-47 and C-53 were built at Santa Monica, California, Long Beach, California, and Oklahoma City, and more than 10,000 of these were produced. Other variants were also built, including the Lisunov Li-2 built in the Soviet Union and the L2D Type 0 transport built in Japan. Civilian production of the DC-3 ended in early 1943, while military versions were produced until the end of the war in 1945. The Super DC-3 was later launched in 1949, but only five were built, with three delivered for commercial use.

DC-3 Variants

The DC-3 had several variants with different specifications. The initial variant was the Douglas Sleeper Transport (DST), with two 1,000–1,200-horsepower Wright R-1820 Cyclone engines and standard sleeper accommodation for up to 16 with small upper windows, convertible to carry up to 24 day passengers. The DST-A had 1,000–1,200 horsepower Pratt & Whitney R-1830 Twin Wasp engines. The initial non-sleeper variant was the DC-3, which had 21 day-passenger seats, 1,000–1,200 horsepower Wright R-1820 Cyclone engines, and no upper windows. The DC-3A had 1,000–1,200 horsepower Pratt & Whitney R-1830 Twin Wasp engines.

Another variant of the DC-3 was the DC-3B, which was a version made for TWA. It had two 1,100–1,200 horsepower Wright R-1820 Cyclone engines and a smaller convertible sleeper cabin forward with fewer upper windows than DST. The DC-3C was the designation for ex-military C-47, C-53, and R4D aircraft rebuilt by Douglas Aircraft in 1946, given new manufacturer numbers, and sold on the civil market with Pratt & Whitney R-1830 engines. The DC-3D was the designation for 28 new aircraft completed by Douglas in 1946 with unused components from the cancelled USAAF C-117 production line, also with Pratt & Whitney R-1830 engines.

The DC-3S, also known as the Super DC-3, was a substantially redesigned DC-3 with a fuselage lengthened by 39 inches and outer wings of a different shape with squared-off wingtips and shorter span. It had a distinctive taller rectangular tail and was fitted with more powerful Pratt & Whitney R-2000 or 1,475 horsepower Wright R-1820 Cyclone engines. Five of these were completed by Douglas for civil use using existing surplus secondhand airframes, while three Super DC-3s were operated by Capital Airlines from 1950 to 1952. The designation was also used for examples of the 100 R4Ds that had been converted by Douglas to this standard for the U.S. Navy as R4D-8s (later designated C-117Ds), all fitted with more powerful Wright R-1820 Cyclone engines, some of which entered civil use after retirement from military service.

Common Specs of the DC-3

• Crew: two
• Capacity: 21–32 passengers
• Length: 64 ft 8 in (19.7 m)
• Wingspan: 95 ft 2 in (29.0 m)
• Height: 16 ft 11 in (5.16 m)
• Wing area: 987 sq ft (91.7 m2)
• Aspect ratio: 9.17
• Airfoil: NACA2215 / NACA2206
• Empty weight: 16,865 lb (7,650 kg)
• Gross weight: 25,200 lb (11,431 kg)
• Fuel capacity: 822 gal. (3736 L)
• Powerplant: 2 × Pratt & Whitney R-1830-S1C3G Twin Wasp 14-cyl. air-cooled two-row radial piston engine, 1,200 hp (890 kW) each
• Propellers: 3-bladed Hamilton Standard 23E50 series, 11 ft 6 in (3.5 m) diameter hydraulically controlled constant speed, feathering
• Maximum speed: 200 kn (230 mph, 370 km/h) at 8,500 ft (2,590 m)
• Cruise speed: 180 kn (207 mph, 333 km/h)
• Stall speed: 68.0 kn (78.2 mph, 125.9 km/h)
• Range: 1,370 nmi (1,580 mi, 2,540 km) (maximum fuel, 3500 lb payload)
• Service ceiling: 23,200 ft (7,100 m)
• Rate of climb: 1,130 ft/min (5.7 m/s)
• Wing loading: 25.5 lb/sq ft (125 kg/m2)
• Power/mass: 0.0952 hp/lb (156.5 W/kg)

The Douglas DC-3 is undoubtedly one of the most iconic aircraft of all time. Its impact on the airline industry during the 1930s and 1940s is still felt to this day. Its success in carrying passengers across the United States was a turning point in air travel, as it demonstrated the viability of air travel as a mode of transportation. The DC-3’s versatility and adaptability made it a beloved aircraft not just for airlines, but also for military use. Its role in World War II helped it become a symbol of American ingenuity and technological prowess. The DC-3 was a pioneer in many ways, and its impact on aviation history cannot be overstated.

Despite being an aircraft that was developed over 80 years ago, the DC-3’s legacy endures. Its classic design and distinctive appearance continue to captivate aviation enthusiasts and casual observers alike. Many restored DC-3s are still in operation, with some being used for commercial passenger service, while others are preserved in museums around the world. The DC-3 remains an enduring symbol of aviation’s golden age, and its significance in the history of air travel will never be forgotten.