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Aviation History
1954
1954 - 1090.PDF
490 PLIGHT, 16 April 1954 AIRLINER OPERATION —from the Engineer s Point of View: A Recent Paper by Mr. B. S. Shenstone BEFORE the Belfast branch of the Royal Aeronautical Society on April 6th, a paper entitled Engineering Problems of Aircraft Operation was presented by Mr. B. S. Shenstone, M.A.Sc, F.R.Ae.S., chief engineer of B.E.A. The lecture was originally to have been given on February 9th, but bad flying weather prevented the lecturer reaching Belfast, and a postponement to a later date became necessary in order to fit in with the arrangements of both the Belfast Branch and Mr. Shenstone. Here follows a summary of the paper, which was phrased in the author's characteristi cally forthright style. The lecturer began by describing his object: to put the problems of the aircraft operator before an audience of designers and manufacturers, and to outline what the operator did about these problems. The airline engineering job was basically simple, for it was to keep the fleet flying and to bring new aircraft along to replace the existing ones. Dealing first with the problem of new aircraft, Mr. Shenstone said that, although the operator did not want to do the manu facturer's design work, the airline would have gathered experience applicable to its new aircraft. Instances in which airline advice was essential included the size and position of the passenger door; location of freight holds; cabin width; seat spacing; galley size; electric power requirements; size of luggage racks; relative need for accessibility of certain items; and many other items. Many of these must be worked out in detail by the design staff and the airline experts in these matters, but these experts should never do the design: that was the designer's job. The operator did not want to have to change his requirements continuously, but his job was complex and the resulting aircraft requirement was a solution to the problems of traffic, routes and politics. Seating capacity or size of the new aircraft was deter mined by the amount of traffic, but this traffic depended on the future level of fares, competitors' aircraft, the travel allowance, the optimum frequency and the politics of the countries on the routes. Many of these factors were changeable and the airline must change with them. The routes, also, were influenced by outside elements. The technical side of new aircraft was sometimes easier than the contract side. The airline always wanted guaranteed deliveries tied up with liquidated damages, and required performance guarantees with damages attached [this rather esoteric phrasing can be broadly explained by saying that, should deliveries or performance fall short of their target, the customer expects com pensation.—Ed.]. Finally, the airline expected the manufacturer to stand up to his design faults: if an aircraft had to be modified because of faulty design, why should the airline pay for it? To feed the designer, the airline must have a technical staff which kept abreast of the experience of its own company and that of other airlines. Such staffs of major companies ranged in size from 100 to 250 people. These people, and many others, came into action when the new aircraft was delivered. Proof of the Pudding "Any new thing is imperfect," Mr. Shenstone's paper continued, "and you never really know an aeroplane until you have tried it on the public. It will have flown hundreds of hours and passed all C. of A. and other tests and still be a headache as soon as it gets into service. The cabin is hot and the cockpit is cold, or vice versa. The water or the doors freeze. Automatic devices are not reliable. There are radio faults. Wing skins start to crack. Water condenses in the cabin. The washing water is too hot. Windscreens collect frost or mist. The starboard wing doesn't de-ice. Cabin heaters have too short a life. Wiring is found defective. These things don't all happen to one type or to aircraft of one nationality but they are all possible." In introducing a new type, there was always the chance of a major defect which might result in grounding it. Most new aircraft types had been grounded and there was always plenty of scope for it. These were the problems of the new aircraft; now for the problems of keeping them flying for ten years. Ten years was a long time, but there were DC-3s which had flown more than 40,000 hours—about 15 years' work. A 10,000- hour civil transport was a young one. In the U.K., it was well to remember that the old H.P.42 never flew more than 13,500 hours, and the Short Empire boats no more than 16,000 hours. The B.E.A. Vikings were only now, after seven years, topping 10,000 hours. During that time they had had over 700 modifica tions, including replacement of a number of major structural members; one grounding due to airframe difficulties; and another caused by airscrew difficulties. But the Vikings had done a good job and, because of their constant development and improvement, they were now better than ever before. A major airline must have good facilities if it was to do a good job. After seven years, B.E.A. were just getting such facilities, in the form of the new base at London Airport. In one U-shaped building were located hangars for minor and major maintenance, overhaul workshops, stores, base offices, supplies and project and development offices—-in short, the whole engineering department. The total floor area was about half a million square feet, including about 200,000 sq ft of hangar area, and the total cost of the building and integral equipment was about Z2\ million. Even with the right factory, there were many engineering prob lems which differed from those encountered in manufacture. B.E.A. had two bases and over 60 stations, all requiring various numbers of engineers. If one included the two London stations, the Corporation had a line engineering staff of 850 and a base staff of 1,750. The staffing of outstations abroad was an interesting problem: "We can staff such stations by sending out people from home; we can get the local airline to do our turn-rounds and minor maintenance for use; or we can employ local engineers. There is no doubt that the most expensive way of doing it is to send our own people out. If we had a stable degree of operation, probably the cheapest way would be to train natives of the country served. If our operation is variable, probably the cheapest way is to get a local airline, if such exists, to do the job. At present, practically all the work at out-stations is done by licensed engineers from home, assisted by local non-licensed labour." When new aircraft were introduced, said the lecturer, re-train ing of engineers was obviously necessary, so that they could cope with the new machines. B.E.A. had set up a school in which the training both of engineers and of flight crews was carried out. Spares and "Mods" The stores problem of an airline was different from that of a manufacturer. Shortly after a new type of aircraft had been acquired, a large proportion of the stores bought might prove to be the wrong spares, and there might be an insufficient number of the right spares. A constant re-examination of the spares require ment took place for the first two or three years of operation of a new type of aircraft, and in this period many parts became obsolete due to modifications. One of the most difficult problems was the time taken for delivery of spares from contractors, which often caused the airlines to over-stock. Another problem was the proportion of the man-hours required between routine and non-routine work. The latter in many cases became equal in amount to the routine work; this was serious, because non-routine work could obviously not be planned ahead in detail. Mr. Shenstone's paper continued: "As manufacturers, you are fully familiar with the terrible problem of modification from one side. The other side is equally difficult, and it is no easy job to work the modifications into our routine maintenance. When the whole fleet is used for operation and there is no aircraft for trial installation, you can, of course, imagine how difficult it is to modify a fleet of, say, 50 aircraft within a reasonable time. Not only must we modify the aircraft, but we must modify all the spares apper taining to the modification, both at bases and at outstations." Budgeting was important, said the lecturer. In the coming year the B.E.A. engineering department would cost about £3,700,000. About a third of this would consist of work done outside the Corporation, e.g., the overhaul of equipment and engines, and other contractual work of an engineering nature. The engineering part of B.E.A.'s total expenditure amounted to about 25 per cent-. In conclusion, the lecturer stated, the job facing airline engineers was rather like having a very long production run extending over a number of years, with each aircraft going down the line many times. Each time it left the base after an overhaul it was different in detail, because of modifications and improvements. Only by these improvements and modifications and by good maintenance techniques could the engineering costs be reduced. If no development were ever put into aircraft, improvements would be very slow. If development effort were limited to that of the original manufacturer, the improvements in economy would still be insufficient. To improve an aircraft to any extent, it required a flexible and willing manufacturer plus an active development department in the airline.
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