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Aviation History
1953
1953 - 0283.PDF
6 March 1953 281 From LOUIS BREGUET, Managing Director and Chief Engineer, Societe Anonyme a* THE characteristics of a commercial aeroplane must be so selected as to ensure transport with safety for the passengers or cargo at a remunera tive price and adequate speed. The cost price per passenger-kilometre per aircraft metric ton, which is rather high for aircraft of small weight, decreases quickly with increasing tonnage. From a weight of forty tons upwards, this decrease becomes slower, but is still appreciable. It seems, therefore, that the transport aircraft of tomorrow will be a machine of over 140,000 lb take-off weight with big freight holds, and which can carry 100 passengers or more in comfort over distances up to 1,250 miles— although, of course, an aircraft of half that tonnage is justified on secondary routes. From the point of view of economy in operation, it seems that it is not expedient at the present stage of technical development to exceed cruising speeds of 500 m.p.h. Both the structure of the aeroplane and the power of its engines depend on these considera tions. For an aircraft of 140,000 lb, the fuselage capacity for cargo and des Ateliers d"Aviation Louis Breguet passengers is such as to require a two-deck arrangement to give the necessary floor space. It is for these reasons that I first evolved the idea of my double-decker aircraft 763, of 112,500 lb weight. I then designed the Super Deux-Ponts, widened, length ened and pressurized, and fitted with compounded piston engines of 3,500 h.p. pending the development of sufficiently powerful gas turbines either fitted with airscrews or of the ducted-fan type. With these gas turbines and with cruising speeds in the region of 400 to 435 m.p.h., the best form of propulsion still seems to be the variable-pitch airscrew, though with the correct by-pass units greater speeds can be justified (but not without some increase in fuel consumption). The figure is half way between those for pure jets and turboprops. With turboprops and /•> 1 speeds of 435 m.p.h. at f) n K. heights of about 30,000 ft, j^ /( Ti specific consumptions 40 A ' *^ ' per cent below those of V/J ^-^ turbojets are possible. \^ X From TRYGGVE HOLM, President, Svenska Aeroplan Aktienbolaget. FLYING is, after all, business. It must imply economical advantages both for the passenger and for the airline operator. An airline passenger nowadays does not enter a plane just for "the lure of flying" or for the pleasure of spending some hours in a comfortable chair partaking of pleasant-tasting refreshments; and nobody in vests money in an airline company for purely idealistic reasons or just for the pleasure of seeing his money "fly away." For the passenger, flying must be a rational method of utilizing his time, and for the shareholder a way of getting a reasonable dividend on the money he has invested. To realize this, aviation cannot only apply to a well-to-do minority of people, but must become available to everybody. Therefore, I regard the introduction of the tourist-class services as one of the most important milestones in the history of aviation. Tourist- class operation has now been going on for about a year and has given such good results that we are justified in foretelling a renascence in air transport. The first condition for complete success of the tourist-class idea is, however, that adequate flying equipment is available. Within this range I think much still remains to be done, which is easily understandable : the tourist-class idea is so new that there does not today exist any aircraft type specially designed on the basis of its principles. The types now being used are all more or less accept able modifications of aircraft types designed for "luxury" traffic. And, when determining the specifications for these aircraft, the designers have, in my opinion, been aiming too much at the best possible, as regards equipment, service arrangements and comfort (not to say luxury) items, without, at the same time, giving sufficient consideration to the economical viewpoints involved. Immediately after the end of the war, Saab was fortunate enough to have intact production facilities at its disposal for the construc tion of civil aircraft, which resulted in our Scandia transport being turned out as one of the first post-war planes of its class. It flew as early as in 1946. The leading principle from the very start of the project was to build a simple, rugged, low-cost aircraft for medium- range services with a relatively moderate cruising speed, since, for the purpose of bringing about a real reduction of the block time over the short ranges in question, it would be necessary to increase flight speed quite considerably—which, however, would have a very unfavourable effect on the operating economy. Increase of air speed by the introduction of turboprop and turbojet civil transport aircraft is already under way, but there will still be a need of aircraft in the Scandia's class. The Scandia was, accordingly, designed to be an economical successor to the popular pre-war aircraft but with "post-war performance"; and it has also been proved to meet ,the requirements for an economical tourist-class aircraft, as fully evidenced by more than two years of airline service. Unfortunately, however, from the purely civil viewpoint, when the large-scale marketing of the Scandia was about to start our production capacity had to be reserved for military aircraft. This difficulty, however, has now been overcome by the technical co-operation we have started with the Fokker works in Holland, and we are now again in a \\ *—~^^ A ft position to offer the ^ l^jrfcciv^?^ \(>JvX-X_*.—~g Scandia at favourable *JnMfcA» delivery rates. From G. R. EDWARDS, Director, Vickers-Armstrongs, Ltd., and Chief Engineer, THERE has been a sustained increase in air travel during recent years and the forward estimates of the world's leading airlines indicate that it is likely to continue in the years ahead. The recent introduction of tourist fares may well bring into the air many thousands of people who have previously used surface transport or may even, due to time and expense, not have travelled at all. This could produce a much sharper increase than that already expected. The effect on surface transport is already making itself felt. The B.E.A. internal services to the North of England and Scotland have proved serious competitors to the railways. Business journeys over long distances, such as the Atlantic, are being made increasingly by air rather than by ship. It may be a pointer that one of our most important customers in the shipbuilding side of our business has ordered a fleet of cargo ships with provision for a very small number of luxury berths. The time may be approaching when ship travel is undertaken mainly for health and pleasure reasons; hard-pressed executives will fly. 1 his is likely to be more so in the new generation brought Aircraft Division. up to regard flying as a normal, as distinct from a slightly dangerous means of transport. Our aircraft division has worked closely with B.E.A. in produc ing the Viscounts 700 and 800, in order to meet the Corporation's conditions of operation. We expect to sell many of both types to the operators of the world, as indeed we are already doing. 1 hey will effectively provide a replacement for the twin-engine aircraft now in use. A longer-range version of the Viscount will probably be the replacement for the four-engined aircraft used on internal services. In the V.C.7 we believe we have a long-range four-jet transport capable of economic operation on both transatlantic and trans-continental routes. I believe that by virtue of our lead in turbine-powered aircraft and by the lead which our Corporations will gain by operating them, Britain has an opportunity to be come a great air Power. <-J2^a<t
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