Editing Curtiss C-46 Commando (section)

==Design and development==
The prototype for what would become the C-46, the Curtiss CW-20, was designed in 1937 by George A. Page Jr., the chief aircraft designer at [[Curtiss-Wright]].<ref name= "Time">[https://web.archive.org/web/20100324172852/http://www.time.com/time/magazine/article/0,9171,849869,00.html "Air Freighter."] ''Time'' magazine, 18 May 1942.</ref> The CW-20 was a private venture intended to compete with the four-engined [[Douglas DC-4]] and [[Boeing 307 Stratoliner]] by the introduction of a new standard in [[Cabin pressurization|pressurized]] airliners.<ref name="jdc24">Carter 1958, p. 24</ref> The CW-20 had a patented fuselage conventionally referred to as a "figure-eight" (or "double-bubble"), which enabled it to better withstand the pressure differential at high altitudes.<ref name= "Johnson p. 45">Johnson 2007, p. 45.</ref> The sides of the fuselage creased at the level of the floor that separated the two portions and shared in the stress of each, rather than 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.<ref name= "Johnson p. 45"/> A decision to use a twin-engine design instead of a four-engines was considered viable if sufficiently powerful engines were available, allowing for lower operating costs and a less complex structure.<ref name= "Johnson p. 44">Johnson 2007, p. 44.</ref>

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, aerodynamically "sleek" airliner, incorporating the cockpit in a streamlined glazed "dome". The engines featured a unique nacelle tunnel cowl where air was induced and expelled through the bottom of the cowl, reducing turbulent airflow and induced drag across the upper wing surface.<ref name= "Johnson p. 45"/> 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]].<ref name= "Love p. 4">Love 2003, p. 4.</ref>

The company approached many airlines to obtain their requirements for an advanced airliner. No firm orders resulted, although 25 letters of intent were received, sufficient to begin production.<ref name= "Love p. 4"/> The design of a 24–34 passenger airliner proceeded to the prototype stage as the CW-20 at the St. Louis, Missouri facility with the initial configuration featuring twin vertical tail surfaces. Powered by two {{cvt|1700|hp|lk=on}} R-2600-C14-BA2 [[Wright R-2600|Wright Twin Cyclones]], the prototype, [[Aircraft registration|registered]] ''NX-19436'' flew for the first time on 26 March 1940 with [[test pilot]] [[Edmund T. "Eddie" Allen]] at the controls. After testing, modifications, including the fitting of a large single tail to improve stability at low speeds were made.<ref name="Bowers p451-2">Bowers 1979, pp. 451–452.</ref><ref name="AE34 p27">Green and Swanborough ''Air Enthusiast'' September–December 1987, p. 27.</ref>

The first prototype was purchased by the [[United States Army Air Forces]] (USAAF) to serve as a master for the series and was named C-55. After military evaluation, the sole example was returned to Curtiss-Wright and subsequently re-sold to the [[British Overseas Airways Corporation]] (BOAC).<ref name= "Love p. 4"/> During testing, General [[Henry H. Arnold|Henry H. "Hap" Arnold]] became interested in the potential of the airliner as a military cargo transport and on 13 September 1940, ordered 46 modified CW-20As as the ''C-46-CU Commando''; the last 21 aircraft in this order were delivered as Model CW-20Bs, called C-46A-1-CU. None of the C-46s purchased by the U.S. military were pressurized and the first 30 delivered to the AAF were sent back to the factory for 53 immediate modifications.<ref name="jdc24"/><ref>Lucariny, J.R. [http://www.jrlucariny.com/site2008/c46clh/c46clh.html "Curtis C-46 Commando."] {{webarchive|url=https://web.archive.org/web/20090106010934/http://www.jrlucariny.com/Site2008/c46clh/c46clh.html |date=2009-01-06 }} ''jrlucariny.com''. Retrieved: 12 April 2012.</ref><ref name= "Johnson p. 47">Johnson 2007, p. 47.</ref> The design was then modified to the C-46A, receiving enlarged cargo doors, a strengthened load floor and a convertible cabin that speeded changes in carrying freight and troops. The C-46 was introduced to the public at a ceremony in May 1942, attended by its designer, George A. Page Jr.<ref name= "Time"/>

A total of 200 C-46As in two batches were ordered in 1940, although only two were actually delivered by 7 December 1941.<ref name="jdc24"/><ref name= "Davis p.11"/> An important change was made: more powerful {{cvt|2000|hp|kW}}c [[Pratt & Whitney R-2800]] ''Double Wasp'' engines replaced the Twin Cyclones. By November 1943, 721 modifications had been made to production models, although many were minor, such as fuel system changes and a reduction in cabin windows.<ref name= "Mondey p. 72">Mondey 2006, p. 72.</ref> Subsequent military contracts for the C-46A extended the production run to 1,454 examples, 40 of which were destined for the U.S. Marine Corps, to be called '''R5C-1'''. The military model was fitted with double cargo doors, a strengthened floor and a hydraulically operated cargo handling winch; 40 folding seats were the sole passenger accommodation for what was essentially a cargo hauler.<ref name= "Mondey p. 72"/> Two C-46 were delivered from [[Higgins Industries]] [[Michoud Assembly Facility|Michoud Factory Field]] in 1942.<ref>{{cite web |url=https://www.airfieldsfreeman.com/LA/Airfields_LA_NewOrleans_E.htm |title=Abandoned & Little-Known Airfields: Louisiana: Eastern New Orleans area |website=[[Abandoned & Little-Known Airfields]] |access-date=11 January 2022 |archive-url=https://web.archive.org/web/20140910085351/http://www.airfields-freeman.com/LA/Airfields_LA_NewOrleans_E.html |archive-date=10 September 2014 |url-status=live}}</ref>

The final large production-run '''C-46D''' arrived in 1944–45 and featured single doors to facilitate paratroop drops. Production totaled 1,430 aircraft.<ref name= "Mondey p. 72"/> Although a one-off '''XC-46B''' experimented with a stepped windscreen and more powerful engines, a small run of 17 '''C-46E'''s 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-46F'''s reverted to the earlier cockpit shape but introduced square wing tips. A sole '''C-46G''' had the stepped windscreen and square wing tips but the end of the war resulted in the cancellation of any additional orders for the type.<ref name= "Johnson p. 47"/>