Douglas DC-6

Updated: October 2026 – Four twin-row radial engines, a pressurized cabin and room for almost 90 passengers: the Douglas DC-6 is one of the aircraft that made travel across continents and oceans an everyday matter after World War II. Between 1946 and 1958, 704 examples were built. Today it has become rare – but not extinct. In Alaska it still hauls freight to remote places, and in Salzburg the former VIP aircraft of Josip Broz Tito shines as the DC-6B of the Flying Bulls. Here you read how the DC-6 came about, which versions exist, how to tell it from the DC-4, DC-7 and Constellation and where you can still see it today.

What is the Douglas DC-6?

The DC-6 is a four-engine piston airliner from the Douglas Aircraft Company of Santa Monica. Technically it is the logical development of the Douglas DC-4: the same basic concept with a low wing, nosewheel landing gear and four radial engines, but with a pressurized cabin, a longer fuselage and significantly more power. The pressurized cabin was the real advance – it made it possible to fly at higher altitude above the weather, smoother and faster than the unpressurized DC-4.

The DC-6 is powered by four Pratt & Whitney R-2800 Double Wasps, 18-cylinder twin-row radial engines with water injection and about 2,400 hp per engine. Late DC-6Bs used versions with about 2,500 hp. Cruising speed is around 500 km/h. Compared with jets that sounds modest, but in the late 1940s it was top class.

Origins: how the C-54 became the DC-6

The DC-6 began as a military project. Still during World War II, in 1944 the US Army Air Forces ordered a lengthened, pressurized version of the C-54 Skymaster with more powerful engines. That became the prototype XC-112A, which first flew on February 15, 1946. When the war was over, the military was initially less interested in the type – Douglas turned it into a civil airliner.

The civil DC-6 first flew on June 29, 1946. Its fuselage was lengthened by a good two meters compared with the DC-4. On November 24, 1946, the first aircraft went to American Airlines and United Airlines, and regular scheduled service began in spring 1947. That put the DC-6 in direct competition with the Lockheed Constellation, which also offered a pressurized cabin – more on that in the article Lockheed Constellation.

The versions at a glance

Over twelve years of production a whole family came about. For spotters, three civil versions and the military offshoots matter most.

Version	First flight	Features	Note
DC-6	June 29, 1946	first production version, shorter fuselage (about 30.7 m)	Passenger aircraft, typically 48 to 68 seats
DC-6A	September 29, 1949	Slightly lengthened fuselage, reinforced floor, large cargo doors on the left	Freighter and combi; first airline use in 1951 with Slick Airways
DC-6B	February 2, 1951	long fuselage of the DC-6A, but without cargo doors	pure passenger version, the most-built with 288 examples
DC-6C	–	like the DC-6A, convertible between cargo and passengers	Convertible version
C-118A Liftmaster	–	Military version of the DC-6A for the US Air Force	101 built
R6D-1	–	US Navy version (later C-118B)	65 built

The DC-6B is still considered the most successful version. It was economical, reliable and usable on short and long routes alike. Pan Am used it from 1952 for tourist-class flights across the North Atlantic and thereby made flying affordable for more people. Some DC-6Bs were later converted into freighters, including a handful with a swing tail for bulky cargo – a conversion that goes back to Sabena.

You often run into the military versions without noticing: some DC-6s that still fly as freighters today are former US Air Force C-118As. If you want to place old serial numbers, the article US military serials helps.

The DC-6 with airlines in Europe and the world

From the late 1940s the DC-6 spread quickly. As early as 1949, KLM, SAS and Sabena were flying it across the Atlantic. According to the literature, operators in Europe also included Swissair, Alitalia, Olympic Airways, France’s UAT and Yugoslavia’s JAT. The German armed forces’ Flugbereitschaft (air transport wing) also used a few DC-6s in the 1960s.

Its end as an airliner came with the jets. Douglas itself still pushed out a faster development with the DC-7, but from the late 1950s jets like the Douglas DC-8 took over long-haul routes. The DC-6 moved on to charter and cargo companies, to firefighting and to smaller operators worldwide – a second career that lasted decades for some aircraft. The Douglas tradition was later continued by McDonnell Douglas.

The Flying Bulls’ DC-6B in Salzburg

For spotters in German-speaking countries, one DC-6 is very special: the DC-6B OE-LDM of the Flying Bulls. The aircraft was built in Santa Monica in 1958 and is thus among the very last DC-6s. Its story reads like a novel:

In the restoration, according to the Flying Bulls, the aircraft received a completely new cabin, four new engines and modern equipment. At first it flew with the US registration N996DM; only about 13 years after its arrival did it receive the Austrian registration OE-LDM. According to the operators it is the first DC-6B ever to receive an Austrian registration. How Austrian registrations are structured is explained in the article OE registrations.

The DC-6B is at home in the glass Hangar-7 on the east side of Salzburg Airport, where it is among the largest exhibits in the collection. The aircraft are serviced in the neighboring Hangar-8, which is not public. You find practical visiting tips at Hangar-7 at Salzburg Airport. If you want to see it in motion, the observation deck at Salzburg Airport is the first address: from there you look across the runway to Hangar-7.

At flying shows the DC-6B is a crowd magnet. At the AIRPOWER in Zeltweg the Flying Bulls are regularly part of the program, and the DC-6B also appears at other events. Which dates it flies in a season is often only set at short notice – an overview of the big events is in Airshows in Europe.

The workhorses in Alaska

While the Flying Bulls aircraft is polished and cared for, DC-6s in Alaska still earn their keep. Everts Air Cargo of Fairbanks flies cargo and fuel with DC-6s and former C-118As to places without road access and is among the last operators worldwide still using the type regularly. The robust aircraft cope with short, unpaved runways – an area of operation where modern jets reach their limits.

How many DC-6s fly there at the moment fluctuates: part of the fleet is in storage or serves as a parts depot. Your best chances are in Fairbanks; occasionally the freighters also turn up in Anchorage. How to spot there is explained in Plane spotting in Anchorage; a proven location is Point Woronzof at Anchorage Airport.

How to recognize the DC-6

DC-6, DC-4, DC-7 or Constellation?

Four-engine postwar piston aircraft are easy to confuse. The finder narrows down the possibilities.

The DC-4 and its military version, the C-54 Skymaster, are the closest relatives. The DC-7 builds directly on the DC-6. You recognize the Lockheed L-1049 Super Constellation by its triple tail, the Boeing 377 Stratocruiser by its bulbous fuselage. A mix-up with the twin-engine DC-3 or the tailwheel DC-2 is hardly possible. A broader introduction is offered by Recognizing vintage aircraft in the sky.

Where you see the DC-6 today

Austria. The OE-LDM in Hangar-7 is your surest chance in central Europe – sometimes on the ground in the hall, sometimes in the air over Salzburg or at flying shows.

USA. In Alaska the Everts freighters fly, and in Dayton the Independence stands. The Pima Air & Space Museum in Tucson shows a VC-118A.

Other places. Static DC-6Bs stand at Ljubljana Airport and in the aviation museum in Sola (Norway), among other places. In Bad Laer in Lower Saxony a former DC-6 stands on a company’s grounds. You should check the condition of such exhibits before a visit.

Photo tips for the DC-6

A DC-6 is a feast for the camera: bare metal, four radial engines and, on startup, smoke and flames from the exhaust stacks.

You can judge how special your sighting is with Judging the rarity of a sighting.

Conclusion

The Douglas DC-6 brought the pressurized cabin into everyday long-distance travel and, with 704 examples, was one of the big successes of the piston era. The DC-6B became the favorite of many airlines, presidents traveled in it, and after the end of its airline career it found new tasks as a freighter and special-purpose aircraft. That you can still see it fly today is thanks to operators in Alaska – and to the Flying Bulls in Salzburg, who made Tito’s former DC-6B shine again.