Douglas DC-7
The Douglas DC-7 is a propeller airliner produced in the years 1953-1958 by the American Douglas Aircraft Company. It was next to the Lockheed Starliner to highlight and end point of the era of the driven piston-type internal combustion engines propeller aircraft at the transition to the jet age dar.
History
Beginning of the 1950s sought some U.S. airlines a successor to the DC-6 with extended range, so as with the competitive model Lockheed Super Constellation in both directions nonstop from one U.S. coast to be able to fly to the other. After initial hesitation on the part of Douglas ' American Airlines ordered 25 aircraft at a cost of 40 million U.S. dollars, which the development costs were covered. The prototype lifted on 18 May 1953, for its first flight in November, the first machine went into the service plan. However, the non-stop flights were due to technical problems often initially only theoretically possible.
The DC-7 was 33.24 meters long, had a wingspan of 35.81 meters and weighed 30 tons empty. Your maximum mass was about 64 tons and could carry depending on seating 82-105 passengers. At the far end of the cabin was a small lounge or bar The DC-7 was very fast for a propeller aircraft and is expected to reach a top speed of over 720 km / h. The travel speed was 555 km / h, the maximum range at 7130 km. The DC-7 was powered by four 18 -cylinder turbo-compound double star motors of the type Wright R -3350, each with 3,250 hp. Just as with the equipped with the same engines Lockheed Super Constellation attended the appended improve performance failure-prone exhaust turbines constantly for engine failures. Technically, the DC-7 is an advanced DC-6, which in turn is based in part on the DC - 4 of 1938. However, the original model sold only in the U.S., because the range for European customers was too low.
As of April 1955, there was the Model DC -7B, the decreed over the original model has a larger range by additional saddle tanks. However, even this increase did not meet the standards of Europe; However, the B model was the North Atlantic on the route New York - cross nonstop London because of the jet stream.
In April 1956, followed with the DC -7C, known as pun too " Seven Seas ", a third variant. This model was the first airliner able to fly not only on U.S. domestic flights to the main wind direction to the west, but also the Atlantic in both directions to cross nonstop. Thus was as yet in the DC -7B no intermediate stop for refueling at Shannon Airport ( Ireland ) or the Gander airport in Newfoundland necessary. For the necessary fuel capacity of 30,000 liters and the higher maximum take-off mass of 65,000 kg, the wing of the DC-4 used to DC -7B no longer sufficed. So in each case a 1.5 meter section was inserted between the inner engines and the fuselage, which increased the wingspan to 38.80 meters. This created a positive side effect to reduce noise levels in the cabin because the engines were now further out. Due to bigger propellers and lower speeds, the vibrations were reduced. The engine power of the C- model was increased to 3,400 hp each and extended the hull to 34.23 meters. The range of the DC -7C was almost 10,000 km. This version was used on the first ultra - long-haul, so on the route San Francisco - London or Amsterdam - Anchorage - Tokyo. KLM led by a non-stop flight from Long Beach to Paris in May 1957 - the flight time was 21 hours and 35 minutes. BOAC faced by competition from Pan Am and forced their DC -7C to order this type, instead of waiting for a revised Bristol Britannia. Another direct competitor was the Lockheed Starliner; However, this was not commercially successful because of its later launch and close the jet age.
Finally, Douglas was planning nor the DC - 7D, for the Rolls- Royce Tyne turboprop engines, each with 4,273 kW ( 5,800 hp) were provided. This was, however, also because of the approaching jet age, not in series.
After her time as a passenger aircraft, many DC-7 were used as cargo or transport aircraft, now called DC -7F here.
A total of 338 DC-7 were built, of which 121 7C models. In 2007, in the U.S. some 70 aircraft of this type registered 74 planes were lost through accidents.
Name
Douglas Aircraft Company planned Already in 1944 an aircraft with the designation DC-7, which should be developed from the C -74, but was not realized.
Military user
- France France
- Colombia Colombia
- Mexico Mexico
- Rhodesia Rhodesia
- United States United States