The DC-7 was developed in response to an American Airlines request for an aircraft that would be superior to the 'Super Connie' used by TWA. Douglas decided to use a lengthened DC-6B to develop the DC-7. The DC-6B was stretched 3 ft. 4 in. to allow an additional row of seats on the DC-7. The DC-7 was equipped with much more powerful engines that enabled the gross weight to be increased by 15,200 pounds. The DC-7B and DC-7C mainly improved fuel capacity and range; however, the DC-7C was stretched another 3 feet 4 inches. The DC-7 is remembered as one of the airplanes that represented the pinnacle of piston-powered commercial transports.
June 29,1946 (original DC-6 model from which the DC-7 was developed)
Four 3,400 horsepower Wright R-3350-18EA-1 Turbo-Compound radial engines
Max speed: 406 mph
Economical cruise: 355 mph
Maximum range: 4,605 miles (with max payload)
Empty: 72,763 lbs.
Maximum takeoff: 143,000 lbs.
Wing span: 127 feet 6 inches
Length: 112 feet 3 inches
Height: 31 feet 10 inches