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Aviation History
1959
1959 - 1276.PDF
FLIGHT, 1 May 1959 AIR COMMERCE 623 WHY T.A.A. BOUGHT THE FRIENDSHIP BY JOHN L. WATKINS, DIRECTOR OF ENGINEERING, T.A.A. SUMMARIZED here is an article by one of the airline industry's mostrespected engineers. It -will be of interest especially to those concerned with the elusive DC-3 replacement. T.A.A. are now taking delivery oftheir 12 Fokker Friendships, and services will begin this month. IT is not always practicable to go on increasing frequencieswhere the traffic demands instead of going in for bigger air-craft. Such a principle has much to recommend it, because the more frequencies operated the better is the public served inchoice of the most convenient service for its specific needs, and the greater is the degree of flexibility for the operator to tailor capacityoffered, route by route, to meet changing volumes of business offering. There are two main considerations which outweigh theseadvantages. Firstly, the specific economy (that is, the direct operating cost per ton-mile of transport performed) of aircrafttends to follow a curve which falls quite appreciably as the size of unit increases, e.g. as the size is reduced below the 25-30 seat(or say 6,000-7,000 lb payload) class, the cost per ton-mile or per seat-mile rises sharply. But one type of equipment alone will not -deal effectively withall aspects of the job. For example, in the Melbourne - Sydney services scheduled today we see one of the world's most notableexamples of high density air traffic, in relation to population, and to other forms of transport. There are over 25 flights a day eachway, representing nearly 1,400 seats. These are filled to an average year round load factor of around 75 per cent. This meansthat jar more people fly between Melbourne and Sydney than travel by all other means of transport combined. Secondly, T.A.A.'s "development" Channel and Gulf Countryservices in Western Queensland and northern South Australia, are serviced by five long routes, covering altogether about 50 portsof call. These are operated once a fortnight with a 21-seat DC-3, giving one and a half seats a day—and a pretty low passenger loadfactor. This means a disparity of at least 1,000 to 1 in the pas- senger traffic volume on different services in the T.A.A. routenetwork. The DC-3. The Douglas DC-3 was the first really successfulairliner to go into widespread use. It represented in its day the ultimate in development of the aeroplane for commercial trans-port. It was costly by the standards of 1935 when it first appeared —24 years ago—at about $100,000, but it was efficient. It had astructure that was safe, robust, and designed for practical main- tenance and long life. It had engines that were dependable, andwhen flown at the weight at which it was designed to operate, ability to carry on, or get back, in the event that one engine failed.It was faster than most commercial aircraft of that era—with its cruising speed of 170 m.p.h. It was comfortable, with cabin heat-ing, individual fresh air outlets, wide adjustable seats, good visibility from the cabin windows, and it was one of the first aircraftto have a comfortable, well-equipped flight deck with a wide field of vision for the crew, effective windshield wipers, and a simpleand efficient hydraulic autopilot. All over the world many airline people, and aircraft manu-facturers, say that there will never be a DC-3 replacement; but their arguments always show they are thinking of the war-surplusC-47 at its disposal price. In some applications the low capital investment needed to put a fleet of C-47s in the air has made pos-sible worthwhile developments in air transport that would not otherwise have taken place. But air transport economics whichbreak down if an adequate allocation from earnings is made for fleet obsolescence are not likely to lead to any permanent orvaluable growth of the industry. In Australia at least, the need for a DC-3 replacement does exist.Actually T.A.A. is still making each week as many flights with DC-3 as with DC-4, Convair and Viscount combined. Of the totalpassenger-miles flown by the whole of the T.A.A. fleet in 1956, 27 per cent were contributed by DC-3. This fell to 18 per cent ofour passenger-miles in 1957 and in 1958 went to 15 per cent of the total. The DC-3 is no longer sufficiently fast to provide an acceptable speed as compared with the vastly improved standards now offered on the main Australian heavy traffic routes. The DC-3 block speed The delivery ceremony at Schiphol on April 6 on outback services is, at the best, 140 m.p.h. This is now morethan 100 m.p.h. less than the standard block speeds represented by the normal inter-capital Viscount and Electra schedules. Thisis a very different situation from that which obtained when T.A.A. started operations. The standard of service being offered to thosecommunities in the more remote parts of our country in respect of what is, after all, the main commodity air transport has to sell,namely speed, is deteriorating badly in comparison with what the city dweller is now offered. Further, the DC-3 is no longer sufficiently comfortable to beaccepted as the normal standard for inland flying. Consistent heat turbulence makes low level operation unpleasant over much ofthe continent for most of the year. The solution is a fast climbing, fast descending, pressurized aeroplane such as is now available forthe passenger on all main coastal services. Finally, the DC-3 is no longer sufficiently economical to beregarded, as it has been for so long, as the best vehicle for use where traffic densities are low. On such routes, the desirability of main-taining a reasonably good frequency of service, apart from any other consideration, makes the application of a large capacity air-craft impracticable. Manufacturers in many parts of the world have invested bigsums in design and even building prototypes during the past 10 or 12 years in the attempt to develop a new small airliner that wouldtap some of the huge potential market for a DC-3 replacement. Vickers tried with the Viking and sold about 100, but they havepractically faded out and the DC-3 is still going strong. Lockheed tried, with the Saturn, and built two prototypes. Beech tried withthe very interesting four-engined Model 34, or Twin Quad, and flew a prototype. Boeing tried with the Model 418. Northrop triedwith the Pioneer, and built a small batch for the U.S.A.F. Hurel- Dubois in France are trying with the very high aspect ratio HD-32,and a few are being built, but no airline has adopted it. Canadair tried with the CL-32 design. Saab in Sweden tried with theScandia, and sold 12. Douglas themselves tried, with the Super DC-3, but failed to arouse airline interest. Handley Page triedwith the four-engined version of the Herald; and so on. T.A.A. carefully analysed at least a dozen proposals in this class, and wereunable to find justification for ordering any of them. They were all piston-engined aircraft and, while all this workwas being done, T.A.A. had entered the turbine age of air transport —the biggest change in 50 years of flight. The Rolls-Royce Dartengine has proved itself, most handsomely, as an economical, thoroughly reliable airline engine. In April 1951 we received a letter from the reconstructedFokker company in Amsterdam asking if we were interested in their idea of a DC-3 replacement powered with two Darts. Wewere impressed with the fact that Fokker, as the result of their preliminary analysis, had come up with a design illustrating ourown conclusions very closely. It had an unusually high aspect ratio, was of very clean aerodynamic design, and altogether lookedrather like a scaled-down Convair. There was only one notable difference—the Fokker wing was ontop of the fuselage and ours was beneath. We prefer the low wing, but Fokker were able to convince us that, in the small airlinerclass, particularly where it is desirable to keep the air intakes well up out of the gravel, the low wing layout leads to a more ungainlyresult than the high wing. Our first Viscounts went into service in December 1954, andfrom the outset our experience with the "revolutionary" new powerplant exceeded our expectations. Its dependability, sim-plicity of control, and economy were better than what we had become accustomed to, even in the best of our piston engineswhich had years of airline experience behind them. This early practical operating experience with the Dart enabled us to putthe necessary realism into our economic and performance analyses of the Friendship. The results satisfied us that here at last was theDC-3 replacement we had been looking for—more speed, more comfort, more economy. The Friendship, according to ourestimates, will cost about 10 per cent less than the DC-3 per ton-mile on a typical inter-city stage. ...
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