C–54 and C–69

The Liberator transport served a useful purpose, but its original design as a bomber did not make it fully compatible with the growing list of wartime personnel transport and cargo needs. In any case, the continuing demand for bombers argued for a different set of production lines to supply a four-engine transport. Fortunately, a new Douglas airliner, the DC–4, seemed to fit the ATC’s requirements. Like the B–24, and unlike the “tail draggers” of the day, the DC–4 mounted tricycle landing gear, giving it a horizontal attitude on the flight line. Original specifications for the DC–4 originated with a proposal funded by f ive separate airlines in the United States. A prototype made test flights in 1938, but only United and American Airlines pushed development that led to the DC–4, which first flew in 1942.

An unpressurized airliner, the C–54 military type appeared in many variants. Early models carried only twenty-six passengers, but the manufacturer quickly introduced stretched versions to carry between forty and eighty people. The C–54B, for example, typically seated fifty medical evacuees or twenty-six stretcher cases. The C–54A represented a heavy-lift type, equipped with an oversized cargo door and capable of loading fourteen thousand pounds or more, including vehicles like trucks and road-building equipment. Later versions of the C–54 carried more than twice the payload and could fly missions of more than forty-four hundred miles at a cruising speed of 220 mph; the airplane boasted a top speed of about 285 mph. Wartime production totaled 953 aircraft, the largest transport to be mass-produced during World War II. A number of executive modifications appeared, though none so well known as the “Sacred Cow,” equipped for the personal use of President Franklin D. Roosevelt. Like the C–47, dozens of C–54 transports soldiered on into the postwar era at Air Force and allied bases on every continent.

Toward the end of the war, C–54 transports were joined by a different four-engine civil airliner equipped with tricycle landing gear and built by Lockheed. In its prewar development as the Lockheed Model 49, the Constellation emerged as a large pressurized aircraft, a feature that permitted flights at higher altitudes where there were fewer weather problems and where lower atmospheric drag conditions allowed for higher speeds. From the start, the Constellation represented outstanding performance, being capable of cruising at 300 mph, carrying more than thirty-two thousand pounds of cargo, and transporting sixty-four passengers over intercontinental distances. Military versions of the C–69 saw limited service, with just twenty-two produced for the AAF and only a few available for operations by the end of the war. But the C–69 heralded the kind of speeds and operating altitudes that became commonplace after the war. Dozens of Constellation variants joined the service through the following years, remaining on active duty into the Vietnam War era in a variety of roles, including electronic surveillance and countermeasures.