Design and developmentEdit
The United States Army Air Forces commissioned the DC-6 project as the XC-112 in 1944. The Air Force wanted an expanded, pressurized version of the popular C-54 Skymaster transport with improved engines. By the time the XC-112 flew, the war was over, and the USAAF had rescinded its requirement.
Douglas converted its prototype into a civil transport (redesignated YC-112A, having significant differences from subsequent production DC-6 aircraft) and delivered the first production DC-6 in March 1947. However, a series of mysterious in-flight fires (including the fatal crash of United Airlines Flight 608) grounded the DC-6 fleet later that year. The cause was found to be a fuel vent located adjacent to the cabin cooling turbine intake. All DC-6s in service were modified to correct the problem, and the fleet was flying again after just four months on the ground.
Pan Am used DC-6B aircraft to inaugurate its first trans-Atlantic tourist class flights, starting in 1952.
Douglas designed four basic variants of the DC-6: the "basic DC-6," and the longer fuselage, higher-gross-weight, longer range versions—the "DC-6A" with large cargo doors forward and aft of the wing on the port (left hand side) with a cargo floor, the "DC-6B" designed for passenger work,had passengers doors only and a lighter floor and the "DC-6C" a "convertible" aircraft built with the 2 cargo doors, but fitted with removable passenger seats. The military version, essentially similar to the DC-6A, was the USAF C-118 Liftmaster, and the USN R6D. The DC-6B, powered by Pratt & Whitney R-2800-CB-17 engines with Hamilton Standard 43E60 constant speed reversing propellers, was regarded as the ultimate piston-engine airliner from the standpoint of ruggedness, reliability, economical operation and handling qualities.[verification needed]
The USAF and USN renewed their interest in the DC-6 during the Korean War, and ordered a total of 167 C-118/R6D aircraft, some of which later found their way into civilian service. Harry Truman's first presidential aircraft was an Air Force VC-118 called The Independence.
Total production of the DC-6 Series was 702 including military versions.
In the 1960s, two DC-6s were used as transmitter platforms for educational television, based at Purdue University, in a program called MPATI (Midwest Program for Airborne Television Instruction).
Many older DC-6 aircraft were replaced in airline passenger service by the Douglas DC-7, but the simpler, more economic engines in the DC-6 has meant that this type has out-lived the more sophisticated DC-7. DC-6/7s surviving into the Jet Age were replaced in front line service by Boeing 707 and Douglas DC-8 aircraft.
2006 marked the 60th anniversary since the introduction of the DC-6.
- United States military designation of an improved version of the C-54 (DC-4); became the prototype DC-6. Eventually designated YC-112A, pressurized, P&W R-2800-83AM3 engines
- Main production variant
- Fitted with cargo door.
- Passenger only variant.
- Convertible cargo/passenger variant.
- One DC-6 bought as a presidential transport with special 25 seat interior and 12 beds.
- Designation of DC-6As for the United States Air Force, 101 built.
- C-118As converted as staff transports.
- R6D-1s re-designated.
- R6D-1Zs re-designated.
- United States Navy designation for the DC-6A, 65 built.
- Four R6D-1s converted as staff transports.
- Main article: Douglas DC-6 operators
- Current operators of the DC-6
- Today, most DC-6s in commercial use are based in Alaska. Several other DC-6s are still in operation for small carriers in South America.
- About 100 DC-6s still fly (or are potentially capable of flight).
- In 2002, 49 were fully active.
- One DC-6A, G-APSA, is in use by Air Atlantique, Coventry, UK. They also own a DC-6B, G-SIXC.
- One is in use by Red Bull in Salzburg, Austria.
- One DC-6 is in use by Namibia Commercial Aviation.
- An unknown number are in use as freighters or waterbombers in Canada and the western US.
- Air Atlantique, a former cargo carrier based in Coventry, England.
Notable incidents and accidentsEdit
- On 12 February 1955, a Sabena DC-6 crashed on mount Terminillo, near Rieti, Italy; 29 people died, including 1953 Miss Italia winner Marcella Mariani.
- On 1 November 1955, a time bomb exploded aboard United Airlines Flight 629, a DC-6, killing 44 people above Longmont, Colorado.
Several DC-6s are preserved in museums. The most well-known is President Harry S. Truman's Independence, which is preserved at the National Museum of the United States Air Force, Wright-Patterson Air Force Base in Ohio.
Aircraft of comparable role, configuration and era
- List of military aircraft of the United States
- List of military aircraft of the United States (naval)
- Pearcy, Arthur. Douglas Propliners: DC-1–DC-7. Shrewsbury, UK: Airlife Publishing, 1995. ISBN 1-85310-261-X.
- Whittle, John A. The Douglas DC-6 and DC-7 Series. Tonbridge, Kent, UK: Air Britain (Historians) Ltd., 1971. No ISBN.
- Yenne, Bill. McDonnell Douglas: A Tale of Two Giants. Greenwich, Connecticut: Bison Books, 1985. ISBN 0-517-44287-6.