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Aviation History
1947
1947 - 2108.PDF
658 FLIGHT .DECEMBER IITH, 1947 Civil Air Operations An Appreciation of the Long-term Problems to be Faced by Airline Operators and Aircraft Designers INTRODUCING his lecture to the Royal AeronauticalSociety on December 4th, Mr. N. E. Rovve said that thesubject was one of many facets and one of no little con- tention, with widely significant variations in different parts of the globe and depending greatly on individual views of the future of air transport as a whole. He consequently limited himself to three broad main problems which covered numbers of subsidiary matters of great significance. The lecturer did not consider safety itself as a problem but as a necessity, and his problems concerned reliability, including regularity, safety in the context of economy, and economy of ' operation. Under the first heading of reliability, he placed precise navigation in all weather conditions, approach, landing and take-off in blind conditions, and air- craft flying qualities as the main problems. Under safety with economy he thought that aii traffic control, design problems and crew fatigue were the main considera- tions ; and for economy of operation he placed first of all the definition of future requirements and the problem of forecast- ing traffic, the development of new types of aircraft and methods of maintenance. To restrict himself to immediate prob- lems was not his intention since the situa- tion in this country was due largely to the aftermath of war and it would not l>e representative of civil air operation gener- ally. There could be no doubt, he said, of the future growth of air transport both of passengers and cargo, especially of the latter, and there was no indication that the rate of increase of traffic was showing any sign of slackening. Such growth had brought problems in operating speeds and hence frequencies which would steadily increase, giving rise to major air traffic control and airport problems. He also considered that the drive for economy would be greatly intensified, compelling designers as well "as operators to new solutions of existing problems; and that cargo-carrying would advance rapidly and require specialized operating organization, design and airports. There would also be a growth in helicopter operations for short stages..'It was important, he said, that the assessment of the long-term problems should be reasonably correct since the solu- tion of short-term problems might be merely palliatives instead of being the early stages in the answers to the long-term problems. Reliability and Regularity A major problem of air transport today was its unreliability, and by unreliability, Mr. Rowe explained, he did not mean susceptibility to accidents but an uncertainty that a scheduled operation would be com- pleted according to plan in all con- ditions. He quoted the cancella- tions, due to weather, of B.E.A. Continental services during the twelve months ending September, 1947, ns an average of 5.4 per cent. The average of the ratio of scheduled miles flown to miles scheduled for four major lines in the United States for the twelve months ending June, 1947 and 1946, was 94.8 per cent and 956 per t?ent respectively. These figures were not strictly com- parative as they might include irregularities due to causes other than weather. They did show, however, what had been achieved, and also the need for improvement. JLAR. N. £. Rowe, C.B.E., Vice-President of the Royal Aero- '"* nautical Society, has been Controller of Research and Long Term Development in the British European Airways Corporation since April 1945. He entered the Air Ministry in 1924, became Deputy Director (Aircraft) in 1940, Director of Technical Development in 1941, and Director General of Technical Development in the Ministry of Aircraft Production in 1944. Average cancellations in B.E.A. Continental Division for period October, 1946-September, 1947. SPRING SUMMER AUTUMN WINTER t- ATlN G CO S LU Q.O J a 0 UNI T \ DIRECT OPERATING COSTS 1 • f . /_ ,. A \ > f.Wp.Vb. c r . 79*. STAGE DISTANCE (D) f =lcad factir. Wp=f>aWood available for stage. Vb =Woek speed. Vc —cruising speed. Assuming that irregularities occurred mainly in bad weather conditions, a standard of 98 per cent regularity would seem to be reasonable. In addition to weather, unserviceability due to mechanical failure also caused irregularity, but that was a problem of design and maintenance and called for energetic action by all concerned. A palliative was to hold more aircraft in reserve, but that was uneconomical and increased the chances of failure. Referring to punctuality, he said that during a period of twelve months ending July this year, 8.9 per cent of services in B.E.A. Continental division were over two hours late, the greater proportion of which were due to weather. Data for express trains in this country showed 4.5 per cent of services to be similarly affected in September, 1947. Mr. Rowe considered the method of operation of airports to be of vital im- portance, and that the biggest factor affecting reliable running was the time dif- ference between operations in clear and low visibility conditions. As an example he. quoted the theoretical capacity of Lon- don Airport in 1953, which was 160 move- ments per hour in contact conditions and two-thirds of that in instrument con- ditions. It was evident that if aircraft were scheduled into airports assuming con- tact conditions but instrument conditions supervened, then there would be irregu- larity which would lead to wholesale cancellation if bad \ eather persisted. A primary condition for reliable running, therefore, was the scheduling of airports for instrument con- ditions, unless frequency of non-operation on any given route system was within the 2 per cent margin of irregularity as in the suggested standard. Improvements would be necessary in navigation, air traffic control, ground and airborne equipment. Also more airports and a greater seating capacity in aircraft to carry increased traffic into the existing airports, would be required. More traffic, especially cargo and mail, would have to run at night, and it was necessary to have a rapid and universal international adoption of up-to-date equipment. He remarked that B.'E.A. insisted at an early stage on I.F.R. schedules at Northolt. For maximum utilization Mr. Rovve considered that scheduled airports demanded precision in the timing of arrivals and departures. It was necessary, there- fore, to have precise definition of position in space and time. It was claimed, he said, that either the American omnidirectional Range system or the British GEE system were basically suitable for route navigation, but both systems needed tome sort of distance-measuring equipment. In both systems air- craft movements were subject to control from the ground within a zone around the airports. Such con- trol, was of great potential import- ance ij^its effect on reliability and economy JM% it was essential that a system SBTOM <he evolved to inter- fere with trafficrmovements only to the minimum "extent needed to en- sure safety; he suggested that as far as possible it should be a monitoring system only. A solution to the blind-approach problem would eliminate at least 50 per cent of existing cancellations out of Northolt, stated the lecturer. Cf =fue/ cost 'per unit time. Present equipment to assist in blind Cs = ti/ns (taxv and take-off + landing 4- excess in climb and glide). =fixed charges -foperoting costs per unit time. =fuel cost per unit time.
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