Por qué las aerolíneas abandonaron rápidamente el DC-7
Video from the channel Flight Zone about Douglas DC-7, linked on its Above Ten Thousand entry. Duration: 10:29. Language: English. Video type: Documentary.
What it's about
English-language documentary explaining why airlines retired the Douglas DC-7 so quickly, Douglas's last major piston-engine commercial airliner.
Historical context
On November 29, 1953, American Airlines inaugurated the first scheduled nonstop coast-to-coast service in the United States with the DC-7, fitted within the 8-hour crew duty limit. Derived from the DC-6, with a fuselage 40 inches longer than the DC-6B's, it was fitted with four turbo-compound Wright R-3350 Duplex Cyclone engines because Pratt & Whitney did not offer a suitable engine. Run at high power to meet published schedules, their power-recovery turbines overheated and failed, and diversions were common. Riddle Airlines found, following Swissair's example, that with more careful engine management the aircraft could be reliable.
Highlights
The DC-7B added some power and optional tanks in the nacelles, and Pan Am flew it across the Atlantic in the summer of 1955. The DC-7C added two 5-foot sections at the wing root plus another 40-inch stretch, reaching 112 feet 3 inches in length, with 3,400-horsepower engines, a top speed of 406 mph, and a recommended cruise of 346 mph; from 1956 it allowed nonstop westbound Atlantic crossings, and BOAC and SAS adopted it. The arrival of the Boeing 707 and the DC-8 made it obsolete within about two years: 338 units were built, from 1959 many were converted into DC-7F freighters, and the DC-6 kept flying for considerably longer.