Douglas DC-6

Douglas DC-6
Douglas DC-6B of Swiss airline Balair in 1976
Role	Airliner/transport aircraft
Manufacturer	Douglas Aircraft Company
First flight	15 February 1946
Introduced	March 1947
Status	49 fully active
Primary users	United States Air Force United States Navy
Produced	1946-1959
Number built	>700
Developed from	Douglas DC-4
Variants	Douglas DC-7

The Douglas DC-6 is a piston-powered airliner and transport aircraft built by the Douglas Aircraft Company from 1946 to 1959. Originally intended as a military transport near the end of World War II, it was reworked after the war to compete with the Lockheed Constellation in the long-range transport market. More than 700 were built, and many still fly today in cargo, military, and wildfire control roles.

The DC-6 was known as the C-118 Liftmaster in United States Air Force service, and as the R6D in United States Navy service.

Design and development

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 By the time the XC-112 flew, the war was over, and the USAAF had rescinded its requirement.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.

Operational history

Passengers deplaning 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

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.

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).^[1]

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.

Variants

XC-112

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

Main production variant

DC-6A

Fitted with cargo door.

DC-6B

Passenger only variant.

DC-6C

Convertible cargo/passenger variant.

VC-118

One DC-6 bought as a presidential transport with special 25 seat interior and 12 beds.

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 re-designated.

VC-118B

R6D-1Zs re-designated.

R6D-1

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

R6D-1Z

Four R6D-1s converted as staff transports.

Operators

Main article: Douglas DC-6 operators

G-APSA in British Eagle scheme

G-APSA displaying at Hamburg

The Red Bull DC-6B landing at Salzburg

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.^[2]
• 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.

Civil operators

•  New Zealand
  • TEAL
•  United Kingdom
  • Air Atlantique, a former cargo carrier based in Coventry, England.
•  United States
  • Air Cargo Express
  • Everts Air Fuel
  • Northern Air Cargo

Military operators

•  Argentina
•  Belgium
•  Bolivia
•  Brazil
•  Chile
•  Denmark
•  Republic of China
•  Colombia
•  Ecuador
•  El Salvador
•  France
•  Germany
•  Guatemala
•  Honduras
•  Italy
•  South Korea
•  Mexico
•  New Zealand
•  Paraguay
•  Peru
•  Portugal
•  Republic of China
•  United States
•  South Vietnam
•  Yugoslavia
•  Zambia

Notable incidents and accidents

• On 29 November 1949, American Airlines Flight 157 crashed while attempting a 3 engine landing in Dallas Texas, killing 28 people.
• 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, USA.

Survivors

Harry Truman's C-118, The Independence

Several DC-6s are preserved in museums.

• The most well-known is President Harry S. Truman's VC-118B Independence (s/n 46-505), which is preserved at the National Museum of the United States Air Force, Wright-Patterson Air Force Base in Dayton, Ohio. It was retired to the Museum in 1965.^[3] In 1977-1978 museum personnel restored "Independence" to its former presidential markings and eagle-like paint scheme. The aircraft is on display in the Museum's Presidential Hanger.

Specifications (DC-6B)

Data from Airliners.net^[4]

General characteristics

• Crew: 3: captain, copilot, flight engineer, plus attendants appropriate to number of passengers
• Capacity: 54-102 passengers
• Length: 105 ft 7 in (32.18 m)
• Wingspan: 117 ft 6 in (35.81 m)
• Height: 28 ft 5 in (8.66 m)
• Wing area: 1,463 ft (135.9 m)
• Empty weight: 55,357 lb (25,110 kg)
• Max takeoff weight: 107,000 lb (48,500 kg)
• Powerplant: 4× Pratt & Whitney R-2800 CB17 "Double Wasp" radial engine, 2,500 hp (1,700 kW) with water injection each
• Propellers: Hamilton Standard 43E60 "Hydromatic" constant speed props with autofeather and reverse thrust

Performance

• Cruise speed: 274 knots (315 mph, 507 km/h)
• Range: 2,610 nm (3,010 mi, 4,840 km)
• Service ceiling 25,000 ft (7,600 m)
• Rate of climb: 1,070 ft/min (5.44 m/s)

See also

Related development

• Douglas DC-4
• Douglas DC-7
  

Comparable aircraft

• Lockheed Constellation
• Boeing 377
  

Related lists

• List of military aircraft of the United States
• List of military aircraft of the United States (naval)
  

References

Notes

Bibliography

External links

• DC-6 Images
• Airliners.net on the DC-6
• Images of an Australian DC-6
• Oldprops.com Many Images
• The Six