FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1960
1960 - 3052.PDF
984 FLIGHT, 23 December 1960 THE DC-3 IS TWENTY-FIVE... a project for a twin-engined low-wing monoplane specificallyintended to beat the Boeing 247, some details of which were reaching Santa Monica from the Boeing plant at Seattle, 1,000miles away to the north. The project is said to have been com- pleted in five days and final details were worked out in the trainby Harry Wentzel and Raymond on their way from Los Angeles to New York, where their proposals were submitted to TWA. On the strength of TWA's expression of interest, Douglasundertook the design and manufacture of the DC-1 prototype. Manufacture started early in 1933 and construction went aheadso rapidly that the aircraft was completed inside six months. It was an all-metal monoplane which employed the stressed-skin"multi-cellular" form of wing construction which had previously been pioneered by John K. Northrop in a successful series ofsingle-engined transport aircraft, starting with the Alpha of 1930. Northrop's company had been acquired by Douglas as a sub-sidiary in January 1932 and the latter firm had built 38 Northrop Gammas employing this form of construction, so it was naturalthat they should apply it to the new design. The important characteristic of the wing was three spanwiseplate webs to take the vertical shear loads and, in conjunction with the stiffened skin, act as the main structural member. Otherfeatures of the DC-1 handed down from Northrop were split flaps on the thin NACA 2215/2209-section wing and long-chordNACA engine cowlings. The DC-1 had a span of 85ft (compared with 74ft of the Boeing 247), a wing area of 942 sq ft (Boeing:836 sq ft) and a length of 60ft. The design gross weight was 17,8001b—considerably more than the 12,6501b of the 247, in spiteof the fact that the Douglas was designed to carry 12 passengers, only two more than the Boeing. The larger size of the DC-1resulted from the type's greater design range and it dictated larger engines than the 550 h.p. Pratt & Whitney Wasps in the 247.Wright R-1820-F Cyclones of 710 h.p. were selected. It is interest- ing that (according to Raymond) the structure weight of the DC-1came out no less than 30 per cent above the design estimates. This and the aircraft's size convinced TWA that the passengercapacity should be increased; so the DC-2 production version, 20 of which the airline ordered on September 4, 1933, had its fuselagestretched by two feet to accommodate 14 passengers. Fitting of variable-pitch propellers, instead of the fixed-pitch type originallyprojected, enabled the gross weight to be increased to 18,0801b and thus improved the percentage structural weight. Before this, on July 1, the DC-1 prototype (X223Y) had madeits first flight at Douglas's Clover Field at Santa Monica. Piloted by the manufacturer's chief test pilot, Carl Cover, the DC-1 hadan eventful first flight. A fault in the fuel system caused the engines to cut whenever the nose was lifted into a steep climb;but, by careful handling, Cover managed to get the aircraft back on to the ground without damage. The fault was easily cured andthe DC-1 was soon being put through an intensive flight-test programme which quickly established its outstanding qualities.Particularly notable was the single-engine performance, which was superior to that of any contemporary. The aircraft was delivered to TWA in December 1933 (asNC223Y) and thereafter was used for proving and experimental flying and for testing various alternative engine installations,equipment and navigational aids. In 1936 Howard Hughes, TWA's chief shareholder, acquired the DC-1 and contemplatedusing it for a round-the-world flight—which, however, he even- tually made in a Lockheed 14. In 1938 the DC-1 was sold toViscount Forbes and shipped to England, where it was registered G-AFIF. Shortly afterwards it was sold to Spain and operatedby the Republican Government airline LAPE during the Civil War. After the war ended, the DC-1 was taken over by theNationalist airline SAETA (later to become Iberia), which put it into scheduled service as EC-AAE on the Spanish domestic routesin May 1939. This famous aeroplane ended its career in December 1940 when it suffered engine failure while taking offfrom Malaga on a scheduled service. The pilot, Capt Rudolfo Bay, managed to land straight ahead without injuring any of theoccupants, but the aeroplane itself was damaged beyond repair. The first DC-2 (NC13301), with its lengthened fuselage, flewfor the first time on May 11, 1934, and made its initial flight with TWA between Columbus, Newark and Pittsburgh only a weeklater, on May 18. It went into regular service in July. This first DC-2, which became known in TWA as "Old 301," gave five yearsof faithful service with the airline during which it flew about 15,000 hours until, in 1941, it was bought with several otherDC-2s by the British Purchasing Commission and shipped to India. There it did good work as a military transport for abouttwo more years before going unserviceable and being cannibalized for spares at Juhu Airport, Bombay. By the time the first DC-2s were in service TWA had increasedits order to 26 and other airlines were also negotiating orders. The DC-2 had the same wing as the DC-1, but its loaded weightwas increased ultimately to 18,5601b. The accommodation for 14 passengers was in single 19in-wide seats at a pitch of 40in, arrangedon each side of a central 16in aisle. The cabin had a maximum width of 5ft 6in and a maximum height of 6ft 3in. A total of 220DC-2s were built, the hundredth being delivered to American Airlines on June 5, 1935, less than 13 months after the first aircrafthad been delivered to TWA. From the end of 1934 ten DC-2s a month were in fact being produced, and 160 had been built forthe airlines by the time production was completed in 1936. Considerable numbers were exported, the first to arrive in Europebeing for KLM; they were landed from the s.s. Statendam on September 11, 1934. Others for Swissair followed soon after-wards. Seven other foreign airlines bought DC-2s. Proved in a Race Impressive evidence of the DC-2's capabilities was provided bythe famous MacRobertson Race, flown from Mildenhall, Suffolk, to Melbourne in October 1934. A KLM DC-2 flown by two ofthe airline's senior pilots, Parmentier and Moll, and carrying a load of special fare-paying passengers, came second in the race,taking three-and-three-quarter days to cover the 12,000 miles; it was beaten only by a de Havilland Comet racer, which took justunder three days. The DC-2 was used by KLM to operate, among other services, its long-distance trunk route betweenHolland and the Dutch East Indies (now Indonesia). Initial development of the DC-1/2 is said to have cost Douglasrather more than $300,000 (£60,000) and production aircraft were sold for $65,000 (£13,000) each. Break-even is believed tohave been reached after 75 had been built. The economic and competitive success of the DC-2 was pheno-menal. The type proved to be significantly cheaper to operate per seat-mile than the Boeing 247, which itself had a specificoperating cost about 20 per cent lower than that of the Ford Tri-Motor which had preceded it. At the same time, the DC-2was about 10 m.p.h. faster than the improved 247D and, with its much larger cabin, had very much more passenger appeal. Manyof the United States domestic carriers soon realized this; five were forced by competitive factors to follow TWA's lead and alsobuy DC-2s. Although DC-2s remained in American service in significant numbers only up to 1941, the type did survive in airlineuse abroad well into the 1950s and a few are probably still flying today. One DC-2 with Australian National Airways had flown DC-3 FLYING COSTS For a Typical UK Independent Operator in 1960 Cost Item Cost per Hour (£) Fuel 10.0 Oil 0.5 Landing fees ... ... ... 2.0 Landing charges* ... ... ... ... ... ... ... ... 2.5 Passenger services ... ... ... ... ... ... ... ... 5.4 Aircrew costs ... ... ... ... ... ... ... ... ... 8.0 Engineering ... ... ... ... ... ... ... ... ... 12.0 Overhead 10.0 Total £50.4 Block speed 150 m.p.h. Passenger seating ... ... ... ... ... 36 32 Total cost per seat mile . ... 2.2 pence 2.5 pence * Appropriate to inclusive-tour-type operations into the Mediterranean area.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
