The DC-7 was
Douglas's last
piston-propelled airliner. It was designed for
American Airlines to compete with
TWA's
Lockheed Constellations on transcontinental routes. At the time, the venerable Connie was the only passenger plane that could go from coast to coast without stopping for fuel, although TWA had its planes stop en route until American offered nonstop service.
At first, Douglas was reluctant to make the investment in the DC-7 program. AA had to pony up $40 million for a 25-aircraft order in order to get Douglas going. Eventually, 105 were sold: 57 went to United, American bought 34, Delta bought 10, and National Airlines bought four. Overseas airlines didn't buy the DC-7 because its increased range over the Douglas DC-6 was not enough to matter on transoceanic routes.
The finished product was basically an extended DC-6 with bigger fuel tanks and upgraded engines. It entered service in 1953 and stayed in production until 1958. When Douglas saw the lackluster response to the original DC-7, they added more fuel to the aircraft and called the resulting model the DC-7B. 112 were sold, but the B still had trouble over long distances, especially if there was a headwind, so Douglas improved upon it again and created the DC-7C, nicknamed "Seven Seas." 120 Seven Seas were sold, and foreign operators such as BOAC and Alitalia were among the customers.
It was ultimately the rise of the Boeing 707 that ended the DC-7's heyday. A few DC-7s still fly today, mostly as freighters and aerial testbeds.
Stats
Powerplant: Four Wright R-3350 radial piston engines (3,400 hp each)
Max speed: 406 mph (650 kph)
Cruise speed: 355 mph (570 kph)
Range: 4,605 mi (7400 km) in -A model; 5,635 mi (9,016 km) in -C model
Empty weight: 72,763 lb (33,050 kg)
Max weight: 143,000 lb (65,000 kg)
Wingspan: 127'6" (42 m)
Length: 112'3" (37 m)
Height: 31'10" (10.5 m)
Passengers: 74 to 110, depending on configuration