Douglas DC-7

Why Douglas built the DC-7

The Douglas DC-7 was the last major piston-engine airliner Douglas built. It grew out of an American Airlines request for an aircraft that could cross the United States nonstop in about eight hours.

Eight hours mattered because flight crews were then limited to eight hours of flying in any 24-hour period. Douglas hesitated until American president C. R. Smith ordered 25 aircraft for $40 million, which covered the development cost.

The prototype flew on May 18, 1953, and American put the type into service in November of that year. It became the first airliner to offer nonstop transcontinental service in both directions, which pushed rival TWA to match it with Super Constellations.

How the DC-7 differs from the DC-6

The DC-7 is a stretched, more powerful DC-6. It kept the wing of the DC-6 and the DC-4 before it, and added a fuselage plug 40 inches longer than the DC-6B.

The bigger change was the engines. The DC-6 used Pratt & Whitney Double Wasp radials, while Douglas turned to Wright for four R-3350 Duplex-Cyclone Turbo-Compound engines.

Each engine produced up to 3,250 hp at takeoff. That extra power made the DC-7 the fastest piston airliner of its day, roughly 25 to 30 mph quicker than the DC-6 and the Lockheed Constellation according to the Delta Flight Museum.

Speed, range and performance explained

The full specification table for the aircraft is on this page. The notes below explain the figures that need context.

The DC-7 has a top speed of 356 kt · 410 mph · 659 km/h, a figure the Smithsonian and the Delta Flight Museum both publish. Airlines cruised well below that. Delta quotes an average cruising speed of 317 kt · 365 mph · 587 km/h.

The weight in the table is the base DC-7 at 122,000 lb · 55,500 kg. The FAA type certificate allows that class of weight only with automatic-feathering propellers, and sets a lower limit without them.

The range is a base-model figure too. The DC-7 flew coast to coast, but it could not reliably cross the Atlantic, which is why the DC-7B and DC-7C followed.

The DC-7 was pressurized, as the DC-6 was before it, and flew at around 20,000 feet, above most weather according to SFO Museum. Its flight crew was three: pilot, copilot and flight engineer.

DC-7, DC-7B and DC-7C variants

Douglas built 338 DC-7s: 105 original DC-7s, 112 DC-7Bs and 121 DC-7Cs. Production ran from 1953 to 1958.

The DC-7B added more power, a higher gross weight and optional fuel tanks in the engine nacelles. Only Pan Am and South African Airways ordered the tanks, and Pan Am began transatlantic DC-7B flights in summer 1955.

The DC-7C Seven Seas came in 1956 and was built for the North Atlantic. Two 5-foot inserts at the wing roots added fuel and moved the engines outboard, which also made the cabin quieter. A second fuselage plug brought its length to 112 ft 3 in.

Its R-3350 engines were rated at 3,400 hp. Carriers such as Pan Am, BOAC, SAS and Swissair used the DC-7C on long international routes, including SAS polar flights to North America and Asia.

A DC-7D with Rolls-Royce Tyne turboprops was proposed for BOAC but never built. From 1959, Douglas also converted DC-7s into DC-7F freighters with large cargo doors.

Why the DC-7 was retired

Jets ended it. The Boeing 707 and Douglas DC-8 entered service in 1958 to 1960, and sales collapsed.

The engines hurt the DC-7 as well. The R-3350 had reliability problems of its own, and airlines that flew the engine hard to meet fast schedules saw failures of its power recovery turbines. Carriers with both types usually replaced their DC-7s before their DC-6s, and some retired them after little more than five years.

Delta flew its last DC-7 service on February 1, 1968. The type then found second lives hauling freight and fighting wildfires.

DC-7 crashes and safety record

The Aviation Safety Network lists 97 DC-7 accidents and incidents between 1955 and 1993. Several shaped aviation history.

On June 30, 1956, United Airlines Flight 718, a DC-7, collided with TWA Flight 2 over the Grand Canyon, killing all 128 people on both aircraft. Caledonian Airways Flight 153 crashed after takeoff from Douala in 1962 and killed all 111 on board, the worst single-aircraft accident of a DC-7.

Baseball star Roberto Clemente died on December 31, 1972, when a chartered DC-7 crashed off San Juan, Puerto Rico, on a relief flight to Nicaragua.

Are any DC-7s still flying?

No DC-7 is known to be flying as of October 2026. The last airworthy member of the family appears to have been Tanker 60, a DC-7B (N838D) that finished its final firefighting season in Oregon and left Medford for Madras on October 14, 2020.

Several survive on the ground. A DC-7B sits at the Delta Flight Museum in Atlanta, and the nose section of American’s Flagship Vermont is at the Smithsonian in Washington. Other DC-7Bs are at the Pima Air & Space Museum and in Charlotte, North Carolina, and Epic Flight Academy in Florida has a former American DC-7.

One fuselage, Charlie 21, ended up as a preschool classroom in Denver.

Frequently Asked Questions

Are there any DC-7s still flying?

None is known to be flying as of October 2026. The last known working DC-7, Tanker 60 (N838D), retired from aerial firefighting in October 2020, and the surviving aircraft are in museums, storage or other static use.

Was the DC-7 pressurized?

Yes. Like the DC-6 before it, the DC-7 had a pressurized cabin and cruised around 20,000 feet, above most weather.

What is the difference between a DC-6 and a DC-7?

The DC-7 is a stretched, more powerful DC-6. It uses the same wing, a fuselage 40 inches longer than the DC-6B and Wright R-3350 Turbo-Compound engines instead of Pratt & Whitney Double Wasps, which made it about 25 to 30 mph faster.

Why was the DC-7 retired?

Jet airliners such as the Boeing 707 and Douglas DC-8 arrived in 1958 to 1960 and made the DC-7 obsolete. Its temperamental Wright engines also made it less popular than the DC-6 on the used market.

How many passengers did the DC-7 carry?

It depended on the airline. The FAA type certificate allows 70 to 99 passengers, while Delta’s early DC-7s held 69 in all first-class seating. The longer DC-7C seated up to 105 in high-density layouts.

How fast was the DC-7?

The top speed was 356 kt · 410 mph · 659 km/h. Delta quoted an average cruising speed of 317 kt · 365 mph · 587 km/h.