Like many other aircraft built during the 1940’s, the Douglas DC-6 was intended for military service yet found its way into airliner service. The DC-6 was Douglas’ next step in the evolution of their DC line of aircraft after the widely popular DC-4.
One issue that the military had with the DC-4 was that it was not pressurized. In 1944 the U.S. Army Air Corps issued a request for an expanded and pressurized version of the C-54 Skymaster with improved engines. Douglas went to the drawing board and eventually presented the DC-6. Named the C-118 Liftmaster in the U.S. Air Force, the DC-6 was built as a pressurized, four piston-powered engine-driven transport plane. The DC-6 took its first flight on February 15, 1946 and was everything the Air Force wanted. Unfortunately, by the time Douglas had created the aircraft, the war was winding down to an end and the Air Force no longer wanted the DC-6. Douglas didn’t worry though. The DC-6 was easily converted from a military craft into a civilian transport and was introduced to airlines in March of 1947.
Pan American Airlines used the DC-6 to fly their first trans-Atlantic passenger class flights in 1952. The DC-6 quickly became the airplane of choice for many airlines since the different models were perfect for either passenger airliners with removable seats or the cargo transporter with two large cargo doors for easy access. It was also at this time that the DC-6 was regarded as the ultimate piston-engine airliner from the viewpoint of reliability, ruggedness, efficiency, and handling.
The Korean War renewed the military’s interest in the DC-6 and quickly saw the Air Force ordering 167 C-118 Liftmasters. Many of them later found a use in civilian jobs after the war. One of them remained in military service as President Harry Truman’s first presidential aircraft, the Independence. The Independence is currently on display in original state at the National Museum of the USAF.
Over the years there were 702 DC-6s built. As with most planes, the DC-6 was slowly replaced by the next big plane. While the DC-6’s durable engines could outlast most new engines, they were no match for the Jet Age. The Boeing 707 and Douglas’s DC-8 replaced the DC-6 in front line service but to this day, several DC-6s are still in active use by smaller airlines and cargo companies.