C-46 Commando
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| C-46 Commando | |
|---|---|
 Wartime photo, USAAF |
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| Type | Military transport aircraft |
| Manufacturer | Curtiss-Wright |
| Designed by | George A. Page |
| Maiden flight | 26 March 1940 |
| Introduced | 1941 |
| Status | Still in use |
| Primary users | United States Army Air Forces United States Marine Corps United States Navy |
| Produced | 1940-1945 |
| Number built | 3140 [1] |
The Curtiss-Wright C-46 Commando was an American transport aircraft originally designed for commercial use although it was primarily used during World War II by the United States Army Air Forces; the Navy/Marine Corps version was known as the R5C. Also known to the men who flew them as "The Whale," or even more irreverently as the "Curtiss Calamity," [2] the C-46 served a similar role as its counterpart, the Douglas C-47 Skytrain, but was not quite as famous or as extensively produced.
Postwar, C-46s were briefly used in their original role as passenger airliners, but the glut of surplus C-47s dominated the marketplace with the C-46 soon relegated to a secondary status. However, the C-46 was adopted as a rugged cargo aircraft for northern and remote locations with its service life extended into the 21st Century. [3]
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[edit] Design and development
The Curtiss CW-20 designed in 1937 as a private venture intended to introduce a new standard in pressurized airliners. The CW-20 had a patented fuselage conventionally referred to as a "figure of eight" (or "double-bubble"[4]) which enabled it to better withstand the pressure differential at high altitudes. This was done by having the sides of the fuselage creased at the level of the floor that not only separated the two portions but shared in the stress of each, rather than just supporting itself. The main spar of the wing could pass through the bottom section which was mainly intended for cargo without intruding on the passenger upper compartment.[4] A decision to utilize a twin-engine design instead of a four-engine configuration was considered viable if sufficiently powerful engines were available, allowing for lower operating costs and a less complex structure. [5]
Engineering work involved a three year commitment from the company and incorporated an extensive amount of wind tunnel testing at the California Institute of Technology (Caltech). The resultant design was a large but aerodynamically "sleek" airliner, incorporating the cockpit in a streamlined glazed "dome." The engines featured a unique nacelle "tunnel cowl" where air was ducted in and expelled through the bottom of the cowl, eliminating turbulent airflow and induced drag across the upper wing surface.[4] After a mock-up was constructed in 1938, Curtiss-Wright exhibited the innovative project as a display in the 1939 New York World's Fair. [6]
Although the company had approached many airlines in order to obtain their requirements for an advanced airliner, no firm orders resulted, although 25 letters of intent were received, sufficient to undertake production. [6] The design of a 24-34 passenger airliner proceeded to prototype stage at the St. Louis, Missouri facility with the initial configuration featuring twin vertical tail surfaces. Powered by two 1,700 hp Wright Cyclones, NX-19436 flew for the first time on 26 March 1940 with famed test pilot Eddie Allen at the controls. After testing, modifications included fitting a large single tail to improve stability at low-speed.
During its testing, General Henry H. "Hap" Arnold became interested in the potential of the airliner as a military cargo transport and ordered 46 modified CW-20s as the C-46 "Commando." The first prototype was purchased by the United States Army Air Force (USAAF) to serve as a master for the series and was designated C-55 but after military evaluation, the sole example, was returned to Curtiss-Wright and subsequently re-sold to the British Overseas Airways Corporation (BOAC).[6]
A total of 200 C-46s in two initial batches were ordered. [2] After the first 25 C-46s were manufactured with the CW-20 pressurized fuselage, built essentially to the original specifications although Pratt & Whitney R-2800 engines replaced the Wright Double Cyclones as well as a number of minor changes (like fewer cabin windows) were adopted. [7]Later production models were unpressurized, but retained the figure eight fuselage configuration. [8]Further military contracts for the C-46A extended the production run to 1,454 examples, 40 of which were destined to be R5C-1s for the US Marine Corps. The military model was fitted with double cargo doors, a strengthened floor and hydraulically operated cargo handling winch; 40 folding seats were the sole passenger accommodation for essentially a cargo "hauler." [7]
The final large production run C-46D incorporated a single door to facilitate paratroop drops and was ordered throughout 1944-1945 for a total of 1,430 aircraft. [7]Although a one-off XC-46B experimented with a stepped windscreen and uprated powerplants, a small run of 17 C-46Es had many of the same features as the XC-46B along with three-bladed Hamilton-Standard propellers replacing the standard Curtiss-Electric four-bladed units. A last contract for 234 C-46Fs reverted to the earlier cockpit shape but introduced square wingtips. A sole C-46G had the stepped windscreen and square wingtips but the end of the war resulted in the cancellation of any additional orders for the type. [8]
[edit] Operational history
Most famous for its operations in the Far East, the Commando was a workhorse in "flying the The Hump" (over the Himalaya Mountains), transporting desperately needed supplies to troops in China from bases in India and Burma.[7] A variety of transports had been employed in the effort but only the C-46 was able to handle the adverse conditions with unpredictable weather, lack of radio aids and direction finders, engineering and maintenance nightmares due to a shortage of trained air and ground personnel and poorly equipped airfields often wiped out by monsoon rains.
The C-46's huge cargo capacity (twice that of the C-47) and long range also made it ideal for the vast Pacific campaign. The C-46 could carry more cargo higher than other Allied twin-engine transport aircraft and it was called upon to transport an incredible variety of cargo, including light artillery, fuel, ammunition, parts of aircraft and, on occasion, various types of livestock. Another advantage of the C-46 over C-47s is that it had single or double fuselage doors, allowing paratroopers to exit the aircraft quicker. The Marines used the Commando in the Pacific island-hopping campaigns, flying supplies in and wounded soldiers out of numerous island landing strips.
Though not built in the same quantities as its more famous wartime compatriot, the C-47, nonetheless, the Commando played a vital role in the Pacific. It wasn't until March 1945 that the C-46 saw duty in Europe, joining the USAAF in time to drop paratroopers in the push for the Rhine. The C-46 proved inadequate for combat. Due to a poorly designed fuel system, gasoline leaked out of the lines and pooled in the fuselage at the wing root and was easily ignited by ground fire. So many C-46s were lost in the drop during the crossing of the Rhine that airborne leaders forbade the airplane's use in future airborne operations. Fortunately, the war ended soon afterward and no further airborne missions were flown.
Despite its success as a wartime military transport, postwar operations revolved around the more plentiful C-47 series with the result that the Commando reverted back to its original civilian role, at first being considered as a commercial airliner by Eastern Airlines. One of its major drawbacks compared to the C-47 was that it had a much higher (up to 50% greater) operating cost, mainly due to its prodigious fuel consumption.[7] Surplus C-46s were sought after, however, for their cargo-carrying capacity and Capitol, Flying Tigers and World Airways were among the first of many air carriers that operated the type on scheduled and non-scheduled routes. The C-46 also became a common sight in South America, widely used in Bolivia, Peru, Brazil, Argentina and Chile where ground transport is hindered by the harsh terrain: Amazon jungle, the Andes and vast swamplands.
C-46 Commandos were also to go back to war albeit under a strange new operator, the Central Intelligence Agency (CIA). The transport played a supporting role in many clandestine operations including the "Bay of Pigs" fiasco. Under cover as Southern Air Transport in the early 1960s, the CIA ended up owning its own airline: Civil Air Transport (CAT) renamed Air America in 1959. Air America eventually operated more than 150 planes and 8,000 employees, playing a significant role in the Vietnam War.
Although their numbers gradually began to dwindle, C-46s continued to operate in many of the remote and northern locations, valued for their workhorse capabilities. In the late 1970s and early 1980s, the Canadian airline Lamb Air operated several C-46s from their bases in Thompson and Churchill, Manitoba. One of the largest operators was Air Manitoba whose fleet of C-46 Commandos featured gaudy color schemes for individual aircraft. In the 1990s, these aircraft were divested to other owner/operators.
Between 1993 and 1995, Relief Air Transport operated three Canadian registered C-46s on Operation Lifeline Sudan from Lokichoggio, Kenya. These aircraft also transported humanitarian supplies to Goma, Zaire and Mogadishu, Somalia from their base in Nairobi, Kenya. Two C-46s of different vintages still operate as "freighters" for First Nations Transportation in Gimli, Manitoba. Buffalo Airways also owns and operates two C-46s, primarily used in Canada's Arctic.
[edit] Variants
- CW-20
- Original passenger airliner design
- C-55
- Original CW-20 prototype and later prototype military cargo transport, also designated XC-46
- C-46A
- CX-46B
- XC-46C
- C-46D
- C-46E
- C-46F
- C-46G
- C-46H
- C-46J
- AC-46K
- Unbuilt version.
- XC-46K
- XC-46L
- XC-113
- Engine change. General Electric T-31 turboprop in place of right hand side R-2800. The aircraft handled so poorly on the ground that it was never flown.
- R5C-1
- Military transport version for the US Marine Corps.
[edit] Operators
[edit] Military Operators
!["Buffalo Joe"'s C-46 in northern Canada, c. 2005](../../../../images/local/thumb/e/e0/C-46_"Buffalo_Airways".jpg/180px-C-46_"Buffalo_Airways".jpg)
- Haitian Air Corps
- Soviet Air Force - One aircraft only.[9]
[edit] Civil Operators
- SADIA
- Varig
- Air Manitoba
- Buffalo Airways
- Lambair
- First Nations Transportation
- Pacific Western Airlines
- Irish International Airlines (Seaboard & Western Airlines)
- Capitol Air (Capitol International Airways)
- Civil Air Transport (later became Air America)
- Delta Air Lines
- Resort Airlines
- Riddle Airlines
- LACSA (Líneas Aéreas Costaricenses S.A. / Costa Rica)
[edit] Specifications (C-46)
General characteristics
- Crew: 4
- Capacity: 50 passengers
- Length: 76 ft 4 in (23.27 m)
- Wingspan: 108 ft 1 in (32.9 m)
- Height: 21 ft 9 in (6.63 m)
- Wing area: 1,360 ft² (126.8 m²)
- Empty weight: 32,400 lb (14,700 kg)
- Max takeoff weight: 48,000 lb (22,000 kg)
- Powerplant: 2× Pratt & Whitney R-2800-51 two-row 18-cylinder radial engines, 2,000 hp (1,500 kW) each
Performance
- Maximum speed: 269 mph (234 knots, 433 km/h)
- Cruise speed: 173 mph (278 km/h)
- Range: 2,950 mi (2,560 nm, 4,750 km)
- Service ceiling 27,600 ft (8,410 m)
- Rate of climb: 1,300 ft/min (6.6 m/s)
- Max wing loading: 35 lb/ft² (170 kg/m²)
- Minimum power/mass: 0.083 hp/lb (140 W/kg)
[edit] See also
Comparable aircraft
Related lists
- List of military aircraft of the United States
- List of military aircraft of the United States (naval)
[edit] References
[edit] Notes
[edit] Bibliography
- Bowers, Peter M. Curtiss Aircraft, 1907-1947. London: Putnam & Company Ltd., 1979. ISBN 0-370-10029-8.
- Davis, John M., Martin, Harold G. and Whittle, John A. The Curtiss C-46 Commando. Tonbridge, Kent, UK: Air-Britain (Historians) Ltd., 1978. ISBN 0-85130-065-0.
- Hardesty, Von. Red Phoenix: The Rise of Soviet Air Power 1941-1945. Washington, D.C.: Smithsonian Institution, First edition 1982, 1991. ISBN 0-87474-510-1.
- Johnson, E.R. "The Airliner that Went to War." Aviation History Vol. 18, no. 1, September 2007.
- Love, Terry. C-46 Commando in action. Carrollton, Texas: Squadron/Signal Publications, 2003. ISBN 0-89747-452-X.
- Mondey, David. The Hamlyn Concise Guide to American Aircraft of World War II. New York: Bounty Books, 2006. ISBN 978-0-7537-1461-4.
[edit] External links
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