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Aviation History
1954
1954 - 2160.PDF
IT. ".£1,6 •jol.4 U ^"*"">« CENTS/200 LB MILE/ 1 V i DOLLARS/MiLE . 1 J FLIGHT, 30 July 1954 147 § 1000 2000 RANGE (st.miles 3000 4000 Direct operating cost and payload/ »S range characteristics, assuming 1,800 § b.h.p. per engine at 23,S0Oft, 58- Q passenger version. DOUGLAS DC-7 sometimes it could be seen gently flexing. Small white spot lights shone from the fuselage on to the outer nacelles. American towns look extremely colourful from the air at night. This is partly due to the clear atmosphere, but mainly it is because more and brighter red and green all-night neon signs are used than in other countries. Because the front row or two of seats between the engines are in a rather noisy area, even more soundproofing has been added and the noise level is now acceptable. There is no com parison with turboprop types but the Seven is as good as, or better than, anything else in its class. Centrally there is very little noise or vibration; well aft, air noises and some buzzing type of vibration can again be felt. The highest point of our flight was in the region of Denver, when we reached nearly 20,000ft. Later a long let-down brought us over Los Angeles in position for the straight-in approach and landing practised widely in America. This seems to be a big improvement on the tortuous cross-country often needed to get ALTERNATIVE AIR Diagrammatic sketch of the carburettor air intake, described on p. 145. into London Airport. The actual time in the air was only 5 hr 45 min and the cruising speed was 310 m.p.h. Formalities on landing after 5f hr in the air (and two hours back on the clock in changing from Central Time, through Mountain to Pacific Standard, were negligible. The luggage was quickly produced, but the walk from aircraft to terminal was long and the wait for the hourly bus even longer. I thought about the alternative $4 taxi to the hotel, and decided that the London coach system was perhaps better as well as cheaper, though the American coaches or limousines do call at hotels instead of at a city terminal, and this is more convenient for most long-distance passengers—particularly for early morning departures. It is not surprising that so many Americans travel by air. The internal services are usually quick and efficiently run and the fares are, as a percentage of average salaries, relatively cheap— though tips to porters add up to a substantial figure. This long non-stop DC-7 service—and there are similar ones coast-to- coast—was both luxurious and rapid. For an American, it costs the equivalent of about £15 if one converts from dollars and allows for the triple-salary figure with a cost of living very Mtle higher than in this country. CALCULATED ROUTE-PERFORMANCE It Et K< G- U N Ass Mo ar (P £l« 0 1000 2000 RANGE fjf.m PERFORMANCE At gross weight of Maximum speed (m.p.h.) Critical altitude (ft) Cruising speed (m.p.h.) Critical altitude (ft) Rate of climb (max. contin. power) at sea level (ft/min) ... at 20,000ft (ft/min) Take-off distance (sea level) (ft) Take-off distance (5,000ft) Absolute range:— At 15,000ft (5,512 gall fuel) At 23.500ft (5,512 gall fuel) 95,000 lb 410 22,000 370 24,500 1,810 1,030 3,400 4,350 3000 Its) 105,000 lb 404 22,100 356 24,200 1,535 800 4.400 5,750 4000 122,200 lb 393 21,550 327 14,800 1,155 480 6,380 * 4,420 st, miles 3,900 st. miles •Maximum take-off weight at 5,000ft is 116,000 lb, and corresponding take-off distance 7,250 ft. Dimensions and weights: Span ... Length Height Wing area ... Take-off power Max. contin. power Max. cruise power.. ... 117ft 6in ... 108ft 11in 28ft 7in ... 1.463 sq ft 3,250 b.h.p, each 2,650 b.h.p. each 1,800 b.h.p. each Max. take-off weight Max. landing weight Operational empty weight (domestic) Operational empty weight (over water) ... Fue Icapacity 122,200 lb 95,000 lb 69,626 lb 71,025 lb 5,526 gall Route couver-Edmonton ^ago-New York w Orleans-Mexico City "" York-Miami iias-New York ... m-Rio de Janeiro Angeles-Chicago onton-Montreal fe-Dakar der-London Angeles-Honolulu • York-Shannon Distance (st. mi) 636 724 912 1,100 1,381 1,608 1,751 1,838 1,986 2,344 2,607 3,072 Payload (lb) 17,795 17,795 17,225 17,795 17,795 17,225 17,795 17,795 17,225 17,225 17,225 17,225 Cruise (m.p.h.) 364 364 363 363 361 360 360 359 358 356 354 353 Block Time (hr min) 2.07 2.23 2.55 3.25 4.12 4.55 5.17 5.31 6.00 7.03 7.48 8.48 Direct Operating Costs ($/mile) 1.04 1.02 1.12 0.95 0.93 1.05 0.92 0.91 1.04 1.03 1.03 0.97 (cents/200 lb- mile) 1.17 1.15 1.30 1.07 1.05 1.22 1.03 1.02 1.20 1.20 1.20 1.13 options: Maximum cruise power (1,800 b.h.p. per engine) at 23,500ft cruise altitude; flight crew, 5 estic); 6 (over-water flights, indicated by reduced payload figure); 3-hr fuel reserve; manoeuvre time uel, and operating costs calculated on A.T.A. formulae; zero wind conditions, except New York-Shannon "ailing eastbound summer wind data). Main factors in the operational and economic performance of the DC-7 are indicated in the diagrams and tables above and below on this page. The machine's performance over typical routes (from 600 to 3,000 mile stage-lengths) shows favourable block-times, at least when compared with those of other piston- engine types, and low unit costs. The Seven is certainly an efficient all-round airliner in the long-range category, and will only be surpassed in speed and economy during the next few years by machines such as the Comet 3, Boeing 707 and Britannia. The DC-7 was introduced into commercial service in the U.S.A. by American Airlines on November 29th last, since when it has broken a number of inter-city transport records on the American continent. Following American's order for 25 machines came further orders for DC-7s and 7Bs from United Air Lines (25), Eastern (12), Delta C and S (10), Panagra (5), National (4), and Pan American (7). The DC-7B.—Aerodynamic flight-testing of the DC-7B, long- range "intercontinental" version of the Seven, has recently been taking place over the Californian desert, and final C.A.A. certifi cation tests are to begin in September. The most significant change is the use of a new flap-linkage system together with a re-positioning of the flap itself to give improved airflow charac teristics. Another development is the provision of extra fuel capacity by the addition of "saddle" tanks forming part of the enlarged engine nacelles, and the optional increased capacity of the centre-wing trailing-edge tanks. The resultant total fuel capacity of the DC-7B is 6,400 gall, and the gross weight of the new aircraft has been increased from 122,200 lb to 125,000 lb. Its engines are the DA4 versions of the Turbo-Compound, which give a power increase over the earlier DA2s of 100 h.p. under all conditions except take-off. Alternative cabin lay out will cater for 40 passengers in the luxury version, or up to 95 for tourist services. Using a 52-seat layout, and allowing for cargo, baggage and mail, the DC-7B (it is reported) will be able to fly 4,000 miles non-stop, with a fuel reserve of almost 1,000 gall. Non-stop London-New York services are a possibility. Conclusion—From the DC-2 to the DC-7, the 20-year record which Donald Douglas can look back on, is unique in the air-transport business. The Seven, like its forerunners, should continue to trans port passengers regularly, efficiently—and profitably—for its operators during a good number of years to come.
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