radial engines were also upgraded to 3,250 hp (2,424 kW) Pratt & Whitney R-4360-49 engines. The aircraft was 31 feet longer than the C-54 Skymaster, and would be 24 feet longer than the proposed C-118 Liftmaster. The second built, 42-65403, c/n 13914, crashed during flight testing on 5 August 1946 at Torrance, California, when it lost a wing during an overload dive test. All four crew bailed out successfully. The fourth aircraft was diverted to a static test article at Wright Field, Ohio, up and virtually every component was tested to destruction between August 1946 and November 1948. This was done in order to determine the individual components' ability to withstand design loads. The fifth C-74 built was modified to be a prototype for the C-124 Globemaster II, which used the same wing as the C-74, but used a much larger fuselage. This newer aircraft quickly superseded the C-74 in service. Douglas had every intention to adapt the aircraft into a civil airliner once the war ended. Pan American World Airways began negotiations in 1944. Their civilian model would be dubbed a DC-7 by Douglas (Model 415A) and the 'Clipper Type 9' by Pan American. Pan American intended to use the 108-passenger aircraft for international travel between New York, Rio de Janeiro, and other cities. The major difference between the military cargo aircraft and the civil airliner was the non-pressurized fuselage of the military C-74 and the pressurized DC-7. The passenger compartment was to be outfitted with a lounge bar, dining area and sleeping cabins for night flights. In June 1945, an order was placed for 26 DC-7 aircraft. With the need for military aircraft greatly reduced by the end of World War II, the order for 50 military aircraft was canceled in January 1946 after production of only 14 aircraft. This cancellation also ended plans to build an airliner version of the C-74 for the civilian market, as the limited military production run increased the cost per civilian aircraft to over $1,412,000 and Pan American canceled its order. Douglas then canceled the DC-7 designation. The DC-7 designation was later used for a completely different civilian airliner project in the early 1950s, having no relationship to the C-74. Operational history Of the 14 Globemasters built, 11 actually saw operational service. All were used by the United States Army Air Forces Air Transport Command (ATC), and later by the United States