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Aviation History
1958
1958 - 0616.PDF
Left, "Imperials also sought tenders in 1934 for ... a large new landplane. This became the Armst ang-Whitworth A.W.27 Ensign." Right, "In 1935 the de Havilland Company . . . started work on their D.H.91 Albatross, aerodynamically a remarkably advanced design." Origins of the Modern Airliner PART 3: IN ENGLAND AND GERMANY, 1934-39 By PETER W. BROOKS, B.Sc, A.C.G.I., A.F.R.Ae.S IN 1934, particularly after the DC-2's striking performance inthe MacRobertson Race, the Board of the British "choseninstrument" airline, Imperial Airways, Ltd., came under con- siderable public pressure to adopt faster aircraft. Until this timeBritish air transport and transport aircraft had held a strong posi- tion internationally, but this was now clearly being underminedby the new American aircraft and by the development of the foreign airline industries which they were making possible. Imperial Airways' main pre-occupation at this time was with theopening-up of the "Empire routes" to the Commonwealth countries, routes which were singularly lacking in good aerodromesand other ground facilities. In planning their new equipment Imperials took the view that the faster British aircraft which theyrequired should be flying-boats, which would not be dependent on the poor Empire-route aerodromes. They accordingly soughttenders in September 1934 for two prototypes of what later be- came the famous Short Empire flying-boat. A fleet of 28 of theseaircraft was eventually ordered, plus further numbers of developed versions. The Empire boat did great work in Imperial Airwaysservice but, in practice, proved economically uncompetitive with the American landplanes and therefore unattractive to airlinesgenerally. It would appear that the direct operating cost per seat- mile of the Empire boat carrying 24 passengers was nearly doublethat of the 21-passenger DC-3. A comparison of total costs would be even more unfavourable to the flying-boat, because of thehigher overheads associated with marine-aircraft operations. The poor competitive showing of the Empire boats and their develop-ments—in spite of their outstanding qualities as aircraft of their type—serves to confirm that, for civil air transport, flying-boatssuffer unacceptable economic and operating drawbacks which, when adequate aerodromes are available, cannot be tolerated. To cover their less pressing landplane commitments, Imperialsalso sought tenders in<1934 for two prototypes of a large new land- plane. This became the Armstrong-Whitworth A.W.27 Ensign,a very large four-engined 40-passenger all-metal cantilever high- wing monoplane, 14 of which were ordered in 1935. Because ofserious delays in development, due in part to the manufacturer's pre-occupation with his military commitments, the Ensign didnot make its first flight until January 24, 1938. It was a very large aircraft for its time, with a wing/area of 2,443 sq ft and agross weight of 48,500 lb. Unfortunately, it proved to be seriously under-powered (13.8 lb/h.p. with a wing loading of 19.9 Ib/sq ft)and, although introduced into service on October 24, 1938, was withdrawn from use after two months to have its 880 h.p. Arm-strong-Siddeley Tiger IX engines re-rated to 935 h.p. The Ensigns returned to service in mid-1939 and did good work during thewar, particularly after they had been re-engined with still more powerful (1,100 h.p.) American Wright R-1820s. Well before the Ensign made its long-delayed first flight, othermore significant four-engined transports were to be developed in Europe. Before this, however, there was another important eventin the United States. On July 28, 1935, Boeing flew the proto- type of the famous B-17, "Flying Fortress" bomber and thus onceagain set a fashion which was to endure. The B-17 was the first four-engined all-metal low-wing monoplane in the "modern"style Its configuration was to be adopted for civil transports by European manufacturers before the Americans did the same.Also in 1935 the de Haviliand Company in this country started work on their D.H.91 Albatross, aerodynamically a remarkablyadvanced design for a four-engined transport aeroplane of rather more than DC-3 capacity but the same seating accommodation.The prototype flew for the first time on May 20, 1937, and the type was produced thereafter in small numbers; but it lacked theingredients for full success because it was of wooden construction. Not only did this make it heavy but operators had begun toappreciate the advantages of a durable all-metal airframe. In Germany, in 1936, two advanced all-metal four-engineddesigns were projected for Lufthansa. Construction of prototypes of the Junkers Ju 90 and Focke-Wulf Fw 200 Condor started soonafter and both types flew for the first time in mid-1937. They were then put into production. Small numbers went into airlineand military service in 1938 and a development of the Condor was extensively used by the Luftwaffe during the War on long-range anti-shjpping work. The Condor was used in limited num- bers by airlines in Germany, and abroad—notably in SouthAmerica. A few remained in service until after the war. However, neither the Ju 90 nor the Fw 200 achieved the widespread successin its designed role which it might have had but for the War. Also in 1938, the British Air Ministry issued the 14/38 and15/38 specifications for two new large transport aircraft, the former roughly in the category of the Ju 90 (whose wing area was1,980 sq ft) and the latter in that of the Fw 200 (wing area: 1,291 sq ft). Soon after, orders were placed to these require-ments for three prototypes of the Short S.32 and for 14 produc- tion Fairey F.C.ls—the first "modern-type" British transports.Both contracts were later cancelled because of the outbreak of war, but it is interesting that these two four-engine, pressurized,all-metal designs—which had wing areas of 2,040 sq ft and 1,300 sq ft respectively—bracketed the size range which was laterto be so successfully exploited by the Americans with their con- temporary DC-4 and Constellation. The S.32 was a mid-wing monoplane with four Bristol Herculesradials. This configuration involved a massive—and no doubt heavy—centre-section frame to carry the spar loads round thecabin and would probably have proved a drawback because of the difficulties of making economical use of the fuselage volume.Furthermore, the design had a tailwheel undercarriage, partly be- cause of the anticipated difficulty of retracting a nosewheel intothe pressurized fuselage. The F.C.I, on the other hand, which had four Bristol Taurus radials, was of conventional low-winglayout with a tricycle undercarriage and a circular-section fuselage with freight hold below the floor. The internal fuselage diameterwas 122in, which compares with the 118in of the DC-4. The wing was a two-spar structure and it was to have been of thenew N.A.C.A. 23-series section which had been developed at Langley Field in 1934. It was 18 per cent thick at the root and10 per cent at the tip and had area-increasing Youngman flaps of advanced design. The F.C.I had a triple tail, rather in thestyle which was later to become familiar on the Constellation, whereas the S.32 had end-plate fins and rudders on the tailplane. The F.C.I would have required some "stretching" to make itfully competitive in developed form with the DC-4 and Constella- tion series, but die design held great promise. It had the addeddistinction of being the first transport aeroplane in the world to be ordered into production which incorporated all the majorfeatures which were later to characterize the DC-4 generation. If the F.C.I and S.32—together with the Ju 90 and Fw 200—had had their chance, American long-range transport aircraft might not have had such a clear field in the years after the war. (To be continued) "In Germany, in 1936, two advanced four-engined designs were pro- jected for Lufthansa. Construction of the Junkers Ju 90 [below] and Focke-Wulf Fw 200 Condor started soon after."
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