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Aviation History
1953
1953 - 1262.PDF
418 FLIGHT A VISITOR'S REACTIONS . . . It was wrong that a wireless valve and a radio tube—"unbelievably, the same thing"—having the same electronic characteristics should differ in physical dimensions by only those few thousandths of an inch needed to make it impossible to put an American tube into a British valve-socket. Returning to the subject of civil transportation, Mr. McGregor said that speed was still aviation's most marketable commodity; but, if in order to attain high cruising speeds, there was a pro portionate increase in let-down approach and landing speeds, then both safety and regularity standards would deteriorate. An air craft that was "hot" near the ground would not accommodate itself to even minute errors in pilotage and regularity would suffer, because minimum limits of cloud-base and visibility had to be raised. But even in the fastest aircraft a passenger was making poor time if there were frequent en route stops, or other delays, or if the frequency of service meant that he had to wait 20 hours before the flight took off. With reference to T.C.A.'s order for Viscounts, Mr. McGregor said ties of sentiment played no part in the final decision. . . . To win the test-match the Viscount had to have, and did have, marked superiority in passenger appeal, reliability and economy, and nothing had occurred since the decision was taken, either in progress or co-operation, which had led T.C.A. to have any doubts as to the wisdom of the decision. t Mr. McGregor then said that he would be foolhardy enough to suggest an order of priority to desirable aircraft characteristics. It was as follows: (1) Safety. (2) Short elapsed-time to destina tion; airspeed; range, frequency; regularity; ground handling. (3) Passenger comfort. (4) Economy of operation. It was only fair, he thought, to remark that no two operators would ever be found who agreed either on this order of priority or even the list of characteristics. Mr. McGregor addressed some concluding remarks to those guests who, like himself, came from abroad. Over a period of years he had been told, first, that Britain could not defend her self in 1940; secondly, that she would not be able to recover after the war; and thirdly, she would never be in a position to contest the air markets, but that night the guests had enjoyed a good dinner, the language spoken had been English and, next day, the first of the S.B.A.C. Show, they would see aircraft designed, developed, built and powered in Britain, not a few of which had already been sold abroad. RESEARCH Points from the Oxford Conference on BY reason of the great post-war activitiy of all the major powers in the guided-missile field, during recent years, the peaceful uses of the rocket have tended to pass unnoticed It was, therefore, a pleasure to attend the recent "Conference on Rocket Exploration of the Upper Atmos phere," which dealt solely with the use of the rocket in pure research. The conference was held in the tranquil surround ings of Queen's College, Oxford, and it would have been intriguing to hear the comments of the 18th-century poet Thomas Tickell, whose portrait looked down on the visitors at dinner, on such projects as the scattering of salt from 50 miles altitude, or the setting up of artificial satellites for cosmic-ray studies. About 80 "'upper-air" scientists were present to hear 25 major papers and a number of short contributions, dealing in the main with the use of sounding rockets in the United States, which is the only country so far to have used them. During the past six years, about 30 tons of instruments have been carried aloft in V.2s, Aerobees and Vikings to altitudes up to 242J miles, and vast quantities of data have been obtained. The papers delivered covered not only die determination of the variation of pressure, density and temperature with altitude, but also the distribution of ozone, electron concentration, long-range radio propagation, high-altitude winds, and so on. It is impossible in a brief review to cover all of diis work satisfactorily, and so only a few of the more interesting points will be commented on here. One of the drawbacks to rocket sounding is the expense of the vehicle. Even the simple Aerobee, which is powered by a liquid- propellant rocket motor and is capable of lifting a 150-lb payload to a height of 75 miles, costs $25,000 without instrumentation. This is a lot of money for a mere one or two minutes' recording- time, and Dr. J. A. Van Allen of the State University of Iowa has developed an inexpensive method of getting small payloads to a great height. It consists in lifting a small instrumented rocket to some 50,000ft by means of a balloon and then firing it in a near- vertical direction. In uiis way almost the theoretical vacuum altitude of the rocket can be achieved, and during this past summer payloads of 30 lb have been sent up over Baffin Bay in this way to heights of 60 miles, in an effort to study cosmic rays near die geomagnetic pole. One other major drawback to the use of the rocket is the very short time during which it is in the region of interest—two or three minutes at most. For many experiments this is not sufficient, and a great deal more could be accomplished if a stable platform could be established outside the earth's atmosphere—in other words, an instrument-carrying artificial satellite. Although the initial cost of such a project would undoubtedly be very high, the cost per minute of recording time, if power were available for several days' experimental work, might very well be quite reason able. The general feeling was that the time was not quite ripe to begin work, but that a few years' work by the guided-missile people might well solve many of the outstanding problems of propulsion and guidance. It is only in rare exceptions that an upper-air parameter can be measured directly, and great ingenuity has been exercised in obtaining the necessary data to allow the various properties to be calculated. One of the main difficulties to be overcome in trying ROCKETRY Exploration of the Upper Atmosphere to obtain readings at various altitudes is the fact that the rocket is either travelling very rapidly upwards or very rapidly down wards! This means, for example, that none of the standard methods of measuring temperature is of any use and that various subterfuges therefore have to be resorted to. One of these is measuring the Mach angle of the shock-wave produced by the nose-cone of the rocket, from which the Mach number and hence the temperature may be deduced. Of various methods the only one that has met with success is that of using an array of movable probes, each provided with a pressure-sensitive pick-up. Each time the pick-up moves tiirough a shock-wave, a signal is pro duced, hence giving the Mach angle. A completely different approach has been that developed by the U.S. Signal Corps Engineering Laboratories. Grenades weighing four pounds each are ejected from an Aerobec at predetermined heights. Cameras on the ground record the flashes, and thus enable the spacial co-ordinates of the grenades to be determined. The times of arrival of the sound-waves at the ground are measured with a microphone array. With this data the mean speed of sound in the layers between the explosions can be calculated, and hence the mean temperature. The same method can be used to deter mine average wind-velocities from die effect of the wind on die downward-travelling sound waves. The wind directions over White Sands Proving Grounds, New Mexico, have been found to be easterly in summer and westerly in autumn and winter. The wind speeds appear to reach a maximum at 55 km/hr, the highest measured speed being 102 m/sec. Of great importance to the would-be space-pilot is the distribu tion of meteors above the atmosphere, and the results so far obtained in the direct determination of diese is reassuring. One technique developed by the Naval Research Laboratory is die simple one of exposing a highly polished metal plate at high alti tude and examining microscopically the minute pits caused by the impact of micro-meteorites. A second method, by Temple Uni versity, is to install microphones next to die rocket skin and record the impacts. The number of collisions recorded on one flight averaged one per square foot per 2.2 seconds—which is about half the number predicted by astronomers. J.H. MORE NATO GROUNDWORK SPEAKING in Paris recendy, Mr. L. P. Weicker, NATO assistant secretary for production and logistics, said that 1,800 miles of pipeline would be laid as soon as possible to supply jet fuel to air bases on die Continent. (Details of the system were given on p. 250 of our issue of August 28th last.) Mr.Weicker revealed the great extent of the pipe system: the major lines will link France, Belgium, Holland and Western Germany, while "minor lines" will be constructed in Norway, Denmark, Italy, Greece and Turkey. Tenders have already been invited for 100,000 tons of steel pipe, and the capacity of the system will exceed 25,000 cu yd per day. Production of armaments is, of course, already well under way to a co-related plan; die £200m fighter-construction programme is furthest advanced (prominent types being the Hunter, Sea Hawk, Swift and Mystere), while a £250m scheme covering other equipment for land and sea forces is in hand.
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