Douglas DC-6

The prototype Douglas XC-112A which first flew on 15 February 1946, converted to DC-6 standard in 1956 and flown by TASSA of Spain from 1963 until 1965

The United States Army Air Forces commissioned the DC-6 project as the XC-112 in 1944. The Army Air Forces wanted a lengthened, pressurized version of the DC-4-based C-54 Skymaster transport with more powerful engines. By the time the prototype XC-112A flew on 15 February 1946, the war was over, the USAAF had rescinded its requirement, and the aircraft was converted to YC-112A, being sold in 1955.[1]

Douglas Aircraft modified the design into a civil transport 80 in (200 cm) longer than the DC-4. The civil DC-6 first flew on 29 June 1946, being retained by Douglas for testing. The first airline deliveries were to American Airlines and United Airlines on 24 November 1946.[1] A series of inflight fires (including the fatal crash of United Airlines Flight 608) grounded the DC-6 fleet in 1947. The cause was found to be a fuel vent next to the cabin cooling turbine intake; all DC-6s were modified, and the fleet was flying again after four months on the ground.

Passengers alighting from an SAS DC-6: Note the upper row of windows, indicating this was built as the optional sleeper variant of the original-length DC-6

In April 1949, United, American, Delta, National, and Braniff were flying DC-6s in the United States. United flew them to Hawaii, Braniff flew them to Rio de Janeiro, and Panagra flew Miami-Buenos Aires; KLM, SAS, and Sabena flew DC-6s across the Atlantic. BCPA DC-6s flew Sydney to Vancouver, and Philippine flew Manila to London and Manila to San Francisco.

Pan Am used DC-6Bs to start transatlantic tourist-class flights in 1952. These were the first DC-6Bs that could gross 107,000 lb (49,000 kg), with CB-17 engines rated at 2,500 hp (1,900 kW) on 108/135 octane fuel. Several European airlines followed with transatlantic services. The DC-6B and C subtypes could often fly nonstop from the eastern US to Europe but needed to refuel in Goose Bay, Labrador, or Gander, Newfoundland, when flying westbound into prevailing westerly winds.[2]

Douglas designed four variants of the DC-6: the basic DC-6, and the longer-fuselage (60 in (150 cm)) higher-gross-weight, longer-range versions—the DC-6A with cargo doors forward and aft of the wing on the left side, with a cargo floor; the DC-6B for passenger work, with passenger doors only and a lighter floor; and the DC-6C convertible, with the two cargo doors and removable passenger seats.

The DC-6B, originally powered by Double Wasp 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.[3]

Similar to the DC-6A, the military version was the USAF C-118 Liftmaster; the USN R6D version used the more powerful R-2800-CB-17 engines. These were later used on the commercial DC-6B to allow international flights.[4] The R6D Navy version (in the late 1950s and early 1960s) had Curtiss Electric constant-speed reversing propellers.

The USAF and USN renewed their interest in the DC-6 during the Korean War and ordered 167 C-118/R6D aircraft, some of which later found their way to civil airlines. Harry Truman's first presidential aircraft was an Air Force short-fuselage DC-6 which was designated VC-118, and named The Independence. It is preserved in the National Museum of the United States Air Force at Dayton, Ohio.

Total production of the DC-6 series was 704, including military versions.[5]

In the 1960s two DC-6s were used as transmitter platforms for educational television, based at Purdue University, in a program called the Midwest Program on Airborne Television Instruction.[6]

Many older DC-6s were replaced in airline passenger service from the mid-1950s by the Douglas DC-7, but the simpler, more economical engines in the DC-6 have meant the type has outlived the DC-7, particularly for cargo operations. DC-6/7s surviving into the jet age were replaced in frontline intercontinental passenger service by the Boeing 707 and Douglas DC-8.

Basic prices of a new DC-6 in 1946–47 were around £210,000–£230,000 and had risen to £310,000 by 1951. By 1960, used prices were around £175,000 per aircraft.[7] Prices for the DC-6A in 1957–58 were £460,000–£480,000. By 1960, used prices were around £296,000.[7] Equivalent prices for the DC-6B in 1958 were around £500,000. Used prices in 1960 were around £227,000.[7]

From 1977 to 1990, five yellow-painted Douglas DC-6Bs were used as water bombers in France by the Sécurité Civile. They were registered F-ZBAC, F-ZBAD, F-ZBAE, F-ZBAP, and F-ZBBU.[8]

United Airlines DC-6 at Stapleton Airport, Denver, in September 1966

Northern Air Cargo operated one of only two DC-6s that had been converted to swing-tail configuration

Pan Am DC-6B at London Heathrow in September 1954 on a transatlantic tourist flight

A cross section of the VC-118A showing interior arrangements

XC-112A

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

DC-6

Initial production variant produced in two versions.

DC-6-1156 a 53- to 68-seat domestic variant with 2,400 hp (1,800 kW) R-2800-CA15 engines

DC-6-1159 a 48- to 64-seat trans-ocean variant with extra crew, increased fuel capacity to 4,722 US gallons (17,870 L), increased takeoff weight to 97,200 lb (44,100 kg) and 2,400 hp (1,800 kW) R-2800-CB16 engines.

DC-6A

Freighter variant; fuselage slightly lengthened from DC-6; fitted with cargo door; some retained cabin windows, while others had windows Precluded. Originally called "Liftmaster" as USAF models. The rear cargo door came standard with a built in 4,000 lb (1,800 kg) lift elevator and a Jeep. The Jeep was a public relations stunt and shortly after, was dropped.[9] Slick Airways was the first airline to operate the freighter variant in April 1951.[10]

DC-6B

All-passenger variant of DC-6A, without cargo door.

DC-6B-1198A a 60- to 89-seat domestic variant with 2,400 hp (1,800 kW) R-2800-CB16 engines

DC-6B-1225A a 42- to 89-seat trans-ocean variant with an increased fuel capacity to 5,512 US gal (20,870 L), increased takeoff weight to 107,000 lb (49,000 kg) and 2,500 hp (1,900 kW) R-2800-CB17 engines.

DC-6B-ST

Swing tail freighter conversion to the DC-6B done by Sabena. Two converted, only one survives currently stored with Buffalo Airways[11]

DC-6C

Convertible cargo/passenger variant.

VC-118

United States military designation for one DC-6 bought as a presidential transport with special 25-seat interior and 12 beds.[12]

C-118A

Designation of DC-6As for the United States Air Force, 101 built.

VC-118A

C-118As converted as staff transports.

C-118B

R6D-1s redesignated.

VC-118B

R6D-1Zs redesignated.

R6D-1

United States Navy designation for the DC-6A, 65 built.

R6D-1Z

Four R6D-1s converted as staff transports.

As of 2014, 147 DC-6s survived, of which 47 were airworthy; several were preserved in museums.

VC-118

On Display

Harry Truman's VC-118, The Independence

• S/N 46-0505 Independence is on display in the Presidential Hangar at the National Museum of the United States Air Force, at Wright-Patterson Air Force Base in Dayton, Ohio. This aircraft served as President Harry S. Truman's personal aircraft until he left office in 1953. It later served as a VIP aircraft for other air force personnel before retiring to the museum in 1965.[21]

VC-118A

On Display

• S/N 53-3240 is on display at the Pima Air and Space Museum in Tucson, Arizona. This aircraft served as President John F. Kennedy's Air Force One until 1962 when it was replaced as the primary presidential aircraft by VC-137C SAM 26000 and relegated to use as the backup presidential aircraft. It was the last propeller-driven aircraft to serve in the presidential fleet.[22]

VC-118B

On Display

• C/N 43207, built in 1951, is on display at the National Naval Aviation Museum aboard Naval Air Station Pensacola in Pensacola, Florida

C-118A

On Display

• S/N 53-3255 is on display at Joint Base McGuire-Dix-Lakehurst, New Jersey. Elvis Presley returned to the United States in this aircraft after serving in the US Army in Germany. As of October 2009, it was being restored. Starting in 2010, this Liftmaster is showcased at the Museum of the United States Air Force at Wright-Patterson Air Force Base, 6 miles northeast of Dayton, Ohio.[23]
• S/N 51-17651 is on display at the Jimmy Doolittle Air & Space Museum, located at Travis Air Force Base in Fairfield, California. This aircraft served first in the US Air Force and was later transferred to the US Navy as Bureau Number 131602.[24]

Flying

• C/N 45563 is currently flying with the Flying Bulls, owner Dietrich Mateschitz, out of Salzburg, Austria.[25] This aircraft was once the private luxury transport of Yugoslav President Josip Broz Tito.[25]

On Display

• C/N 45550 is displayed at Coventry Airport at Baginton, United Kingdom. Built in September 1958, this aircraft spent most of its life in Southeast Asia, and after serving with the CIA and Royal Air Lao, Air Atlantique Group bought it in 1987. Its last commercial flight was on 26 October 2004. It was featured in the 2006 James Bond film Casino Royale. No longer flying, it was converted into a static restaurant at Coventry airport, the "DC-6 Diner".[26]

In Storage

• Two DC-6s that belonged to Aerosur, a defunct Colombian airline, are abandoned and parked in Alfonso Bonilla Aragón International Airport of Cali, Colombia.[27]

On Display

• Everts Air Cargo retired the DC-6A N6174C "Good Grief" on 2 October 2016, after it made the final flight from Anchorage to Chena Hot Springs, concluding its 62-year flight career.
• A Republic of China Air Force DC-6B 18351 "Chung Mei" served as presidential aircraft from 1949 to December 1972 and army general aircraft until retired in December 1978, is parked at Republic of China Air Force Museum.

Related development

• Canadair North Star
• Douglas DC-4
• Douglas DC-7

Aircraft of comparable role, configuration, and era

• Boeing 377 Stratocruiser
• Handley Page Hermes
• Lockheed Constellation
• Lockheed L-049 Constellation
• Lockheed L-1049 Super Constellation
• Lockheed L-1649 Starliner

Related lists

• List of military aircraft of the United States
• List of United States Navy aircraft designations (pre-1962)

Wikimedia Commons has media related to Douglas DC-6.

• Boeing: Historical Snapshot: DC-6/C-118A Liftmaster Transport
• DC-6 Images
• Airliners.net on the DC-6
• Oldprops.com Many Images