<p>Curtiss' capable C-46 has always had to live in the shadow of the C-47. Sharing the latter's airliner origins, it was larger, heavier and more expensive, factors which counted against it in wartime. It made a name for itself in the Far East and Pacific theaters and, after the war, went on to see action again over Korea and even Vietnam.
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<p>Development of the Curtiss-Wright CW-20, later to become the C-46 and at the time the costliest project ever undertaken by its well-known builder, began in 1936 under chief designer George A. Page. A new generation of airliners was due to replace the Curtiss Condor and other biplane types. Although the Douglas DC-3 was entering service with American Airlines and other carriers, the CW-20 seemed to offer promise as a larger, longer-range commercial ship, powered by two 1,650-hp (1,230-kW) Pratt & Whitney R-2800-17 Double Wasp 18-cylinder radial engines. For maximum internal stowage, the CW-20 was designed with a cross-section of two circular segments, or lobes, intersecting at a common chord line, giving the mistaken impression of a 'double decker'.
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<p>Construction of the CW-20 was begun, in advance of actual airline contracts, at Curtiss's St Louis, Missouri plant. The CW-20T prototype, NX19436, or c/n 101, powered by two 1,600-hp (1,193-kW) Wright R-2600 Cyclone engines and distinguished by a cumbersome twin-fin empennage, was first flown on 26 March 1940 by Edmund T. (Eddie) Allen. Curtiss revealed the existence of the new aircraft on 11 April 1940 and made one of history's forgotten gestures by giving the CW-20 the name Substratosphere Transport. For Americans, the aircraft's real potential was not obvious until 7 December 1941, when Pearl Harbor sidetracked the CW-20's airline career and took it into uniform.
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<p>The aircraft was a conventional, cantilever low/mid-wing monoplane transport with semi-monocoque fuselage, fully retractable landing gear, and cabin windscreen flush with its fuselage contour. The crew numbered four. Fairing plates on the prototype CW-20 which had smoothed over the indentation at the double-lobe fuselage intersection were discarded on subsequent machines, it having been found that the fairing provided no reduction in aerodynamic drag. The CW-20 prototype soon acquired, as the CW-20A, the cantilever single fin rudder and tail unit which characterized every machine to follow, the twin-tail configuration having proven inadequate in tests.
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<p>Although shown to airline executives and noted flying as a 'civilian' in natural metal over New York City, the prototype was impressed into USAAF service on 20 June 1941 as the sole C-55 (41-21041) and, three months later, was sold to British Overseas Airways Corporation (BOAC) with the registration G-AGDI, and named 'St Louis'. Alarmed by its deficiencies in air transport (the word airlift was not used then), the US Army Air Forces (USAAF) was attracted by the cavernous double-bubble fuselage of the Curtiss design. The main compartment could accommodate (in addition to general cargo) 40 fully-equipped troops, up to 33 stretchers, five Wright R-3350 engines or their equivalent tonnage in other freight. In September 1940, the USAAF ordered 200 C-46s, company designation CW-20B. The basic design was fixed and plans to pressurize the aircraft were dropped. A wing fuel-leak problem was resolved through field modification only much later.
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<p>Production was shifted to Curtiss's Buffalo, New York, plant where the first C-46 (41-5159) was delivered to the USAAF on 12 July 1942. Further orders followed. The C-46A (CW-20B) model, from the 26th production airframe onward, introduced a large cargo-loading door, a cargo floor, and fold-down seats along the cabin wall; 1,491 were built by Curtiss at Buffalo, St Louis and Louisville, Kentucky. The USAAF planned to use a second manufacturer, Higgins Industries, Inc., of New Orleans, Louisiana, to build 500 C-46As plus 500 Curtiss C-76 Caravans, the latter a mostly wood design intended to benefit from its lack of reliance on strategic materials. When it became clear that sufficient steel would be available, the latter machine failed to reach production and in the end Higgins built only two C-46A airframes, the first (43-43339) being delivered 1 October 1944.
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<p>The XC-46B (43-46953) was a conversion (CW-20B-1) of a Louisville-built C-46A with 2,100-hp (1,566-kW) Pratt & Whitney R-2800-34W engines and a 'stepped' windshield which broke the clean flush lines of the fuselage. No clear historical detail has survived regarding the C-46C, which may have been another experimental C-46A conversion fitted with rocket-assisted take-off gear. The flush windshield was retained in the C-46D (CW-20B-2), which had double loading doors; 1,410 of the machines were built at Buffalo.
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<p>The stepped windshield, the only true distinguishing feature among all C-46 models, was reintroduced with the C-46E (CW-20B-3), which was powered by R-2800-75 engines and employed the three-bladed Hamilton Standard propeller rather than the four-bladed Curtiss Electric propeller used in most C-46 models. In later years the two propeller types would be virtually interchangeable, with operators preferring the slightly less efficient three-bladed type because of its greater reliability. Only 17 examples of the distinctive, stepped-windshield C-46E were built.
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<p>The Buffalo-manufactured C-46F (CW-20B-4) reverted to the original windshield profile and cargo doors. The sole C-46G (4478945), company designation CW-20B-5, was powered by R-2800-34Y engines and was later modified as the sole XC-113 to test the Curtiss-Wright TG-100 gas turbine, although it is unclear whether this testbed ever actually flew. Variants of the Curtiss Commando which were never built at all include the C-46H, intended to have twin tailwheels, the C-46J, with stepped windscreen, and the XC-46K, to have been powered by Wright R-3350 engines. Three XC-46L conversions with R-3350s were built and flown.
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<p>In 1942, the USAAF began to employ C-46s on South Atlantic ferry operations. Lawrence Rogers, a wartime ATC sergeant, recalls the aircraft arriving and departing Accra being "an impressive sight", although Rogers is less cheerful about the machine he saw explode in mid-air moments after lift-off: "That was impressive in a different way." USAAF Troop Carrier Command (separate from ATC) took delivery of C-46s in 1943 at Baer Field, Fort Wayne, Indiana. Because of its range and durability the C-46, although used in airborne operations in Europe, went primarily to the Asian and Pacific theaters.
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<p>The Curtiss C-46 Commando is best known as the mainstay of the massive air transport supply effort undertaken from the Assam region of India to supply friendly forces in southwest China. Flying the 'Hump', as this treacherous crossing of the Himalayan massif became known, was a task fraught with peril for the men and C-46s of Colonel Edward H. Alexander's India-China Wing of ATC. The aircraft were loaded and flown under the most primitive conditions, their fuel pumped by hand from drums, the Assam airfields largely unpaved and transformed into quagmire by monsoons which poured down half the year. On the 500-mile (805-km) Assam-Chunking route, C-46s had to haul cargo over ridgelines looming at 12,000 to 14,000 ft (3,660 to 4,265 m), even though ice began to form on the wings at 10,000 ft (3,050 m). In August 1942, using a few C-47s, the USAAF had been able to transport only 170,000 lb (77,110 kg) of cargo over the India-China route; by December 1943, with many C-46s, the figure rose to 25.18 million lb (11.42 million kg). Short on spare parts, flying in unbearable wet and cold with minimal navigation aids, taking off at maximum overload weight, the C-46 crews were a lifeline to Chiang Kai-shek's Chinese forces and General Claire Chennault's 14th Air Force at a time when the Japanese were active all around. During one of these flights Captain Wally A. Gayda shot down at close range a Japanese fighter, apparently a Nakajima Ki-43, by firing a Browning Automatic Rifle through his C-46 front cabin window and killing the pilot.
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<p>About 40 C-46As were assigned USAAF serials but were completed with BuAer numbers, as R5C-1s for the US Marine Corps, serving at first with MAG-35 in the southwest Pacific. A few remained in service with the USMC during the 1950-53 Korean conflict. Contrary to most accounts, a few R5C-1s were ultimately transferred from the US Marines to the US Navy, at least one becoming an R5C-1T trainer at NAS Memphis, Tennessee in about 1954.
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<p>C-46s continued in widespread USAAF service after VJ-Day, especially with Troop Carrier Command. Some were employed in tests of glider-towing techniques, including 'hard' tows with the gliders coupled close behind the tug. The C-46 is not thought to have been a factor in the Berlin Airlift, but was widely used by the newly independent US Air Force (USAF) well past the late 1940s. The C-46E was declared obsolete in 1953, apparently as a result of its paucity and lack of commonality with flush-windscreen models, but C-46A, C-46D and C-46F airframes continued with USAF Reserve squadrons. TC-46D trainers served with USAF Air Training Command as late as 1955.
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<p>Long-lasting airframes continued in USAF markings well past the 1950s. In addition, the USAF employed private operator Civil Air Transport (CAT) to fly civil-registered C-46s on military charter flights, an example being Taiwan-registered B-858, originally a C-46D (44-78405). A counter-insurgency (COIN) version of the C-46 was developed in the early 1960s for USAF's 1st Air Commando Wing for combat operations in South Vietnam, although little actual modification of the airframe appears to have taken place and, unlike the 'gunship' C-47, it was unarmed. These were diverted to the Panama Canal Zone where they served as late as June 1968, the apparent cut-off date for American military C-46s.
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<hi style=hdr1>Specification</hi>
<hi style=hdr2>Curtiss—C-46 Commando</hi>
<list style=aflst>
<item><hi format=bold>Type:</hi> medium-range passenger/cargo transport
<item><hi format=bold>Powerplant:</hi> two 2,100-hp (1,566-kW) Pratt & Whitney R-2800-34 Double Wasp 18-cylinder radial piston engines driving three-bladed Hamilton Standard propellers
<item><hi format=bold>Performance:</hi> maximum speed 270 mph (435 km/h) at 10,000 ft (3,048 m); cruising speed 235 mph (378 km/h) at 9,000 ft (2,743 m); service ceiling 22,000 ft (6,706 m); range 1,800 miles (2,897 km)
<item><hi format=bold>Weights:</hi> empty 29,300 Ib (13,290 kg); maximum take-off 50,000 lb (22,680 kg)
<item><hi format=bold>Dimensions:</hi> span 108 ft 0 in (32.92 m); length 76 ft 4 in (23.27 m); height 21 ft 9 in (6.63 m); wing area 1,358 sq ft (126.16 m<su>2</su>)
