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Aviation History
1952
1952 - 1657.PDF
time to Manoeuvre JAMESON'S "APPROACH GYM NASTIC" : This diagram, drawn during the I.A.T.A. technical conference at Copenhagen by Mr. D. M. Jameson, of the Air Registration Board, is an attempt at visual inter-relation of all the factors involved in the approach and landing problem. FINDING THE RIGHT APPROACH . . . at least equal to that which his aircraft is covering in that time. It was stressed, however, that, if Joe must have 15 seconds in which to do a certain job, bis aircraft should not have so high a landing speed as to prevent him from getting that time allowance. If it does, he must reach his point of decision further back along the approach and the aircraft will require a correspondingly much higher minimum. Delegates also underlined the importance of the relationship between the pilot's tranquillity of mind and (a) the stability of his aircraft during changes of power, and (b) its stall characteristics during flare-out. Flaps, it was felt, should retract very quickly up to the approach or climb setting during an overshoot, but more slowly thereafter. Finally, Joe was determined to be very much a creature of habit and instinct, capable of performing unusual actions only if he could practise them constantly. It was thus concluded that any approach procedures or devices worked out for his use should be based on his normal reaction and not on special ability. The conference stressed that human engineering must be given a great deal more research and study. Consideration was then given to the problem of lowering the operational ceiling for approach and landing. The 200ft ceiling was felt to be justified more by custom than by rational analysis. Fully automatic landings under absolute zero conditions were felt to be feasible, but it was thought that the number of extra landings thereby facilitated would not justify the cost. The conference decided that the downward limit of improvement was within 100ft of the ground. Following discussions of the I.L.S. system, which provides the pilot with a glide-path and a localizer which tells him the displace ment of the aircraft from the extended centre-line of the runway, it was decided that the indications of height and distance which this system provides at the critical stage of the approach could be made more accurate and reliable. Furthermore, the information should be related not so much to the threshold of the runway as to the critical height at which Joe must make his decision. This would permit him to use a longer, shallower flare-out before land ing and to make greater use of the first section of the runway and the whole range of approach lights. Other possible improvements to the I.L.S. system considered at the conference included the restriction of angular coverage afforded by the localizer to a minimum of about 10 deg to each side of the "on course" zone, in order to obviate beam-bending. The system, it was felt, should be planned to provide reliable guidance down to a height of 50ft. On the subject of visual aids, it was emphasized that runway and approach lights and runway markings should be properly balanced, particularly in regard to the intensity of the lights themselves, and developed to the same standard. There was agreement on the need for carrying approach-light guidance forward on to the runway. Unless the pattern of visual guidance was improved, the benefits of flight directors such as the Zero Reader would largely be wasted. A recent development of the Ministry of Supply's Blind-Landing Experimental Unit was cited as a good example of possible improvement; the system involves the installation of stub bars of lights at right-angles to, FLIGHT, 13 June 1952 719 and outboard of, the runway- lights in the first 2,000ft of the runway at 500ft intervals. It was agreed that the outer portion of the approach-lighting configuration should be basically designed for use with manual coupling, the centre portion for manual and Zero Reader types of coupling and the inner portion for all types of coupling. After discussing the vexed ques tion of meteorology, the con ference concluded that although it was desirable to provide Joe with runway visibility and slant visi bility in addition to the informa tion now given (a statement of ceiling and visibility as observed from the weather office—some times miles from the runway), the problems of forecasting should be given further study before any specific recommendations were made. The conference next con sidered economic aspects, deciding that any improvement in present operating conditions was bound to reduce overall airline costs—by cutting not only delays and diver sions, but also the economic penalty imposed by extra fuel loads. It was urgently necessary for manufacturers to realize the serious implications which result if an aircraft cannot be operated with required regularity under existing conditions. Study by airlines of the accompanying diagram was recommended. The conference drew no specific conclusions, for its task was to develop a record of information for further study, but the I.A.T.A. Technical Committee afterwards stated that: "Integrated approach and landing aids consisting of an I.L.S. and visual aids such as those recommended by I.A.T.A. are considered now capable of producing a good degree of success with most current (1952) types of transport aeroplanes, using standard instrumentation, down to runway visual ranges substantially lower than present operating minima. Further improvements in electronic or other aids or couplings are expected in the future either further to reduce the runway visual range required or to increase regularity." In addition, it is probably safe to conclude that while the development of some new system answering all the problems in all weather operations is not impossible, no such system is antici pated at present. The conference also left a definite impression that there is a lower limit to improvement in weather minima beyond which the cost may prove prohibitive, and that the use of higher landing speeds may even cause minima to be raised. This brief outline may appropriately be concluded by an encouraging statement issued by I.A.T.A. on the overall benefits of the conference : "... A new pattern has been set for the resolu tion of those technical problems which the airlines bring into the framework of I.A.T.A. ... it promises to be a most effective one. With the development of the air transport industry, subjects which could formerly be allotted to specialist groups are becoming more and more closely interrelated. The problems which face the airlines during the coming years are obviously growing in complexity and their solution will benefit from, if indeed it does not absolutely require, initial consideration by groups in which all interested parties participate. In the Copenhagen sessions, the electronic engineers derived considerable value from a greater knowledge of how their work is related to that of the lighting engineer and to the actual performance of the aircraft, the dimen sions of the aerodrome and the pilot's flight problems. The same is true, in many variations, of all of the other types of specialists participating." A FILM ON OIL FILMS A NEW film produced by the Esso Petroleum Co., Ltd., and entitled The Basic Principles of Lubrication, is now available (in 16mm copies) for loan to universities, technical colleges, research organizations, trade associations, and others to whom it may be of interest. Beginning with an explanation of the elemen tary laws of friction, the film is divided into four parts: friction; fluid-film lubrication; boundary lubrication; and extreme- pressure lubrication, and full use is made of laboratory experi ments, micro-photography, animated diagrams and radio-active techniques. The running time is 55 minutes. Applications for loan of the film should be made to the Manager, Industrial Sales Department, Esso Petroleum Co., Ltd., 36 Queen Anne's Gate, London, S.W.i.
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