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Aviation History
1963
1963 - 1779.PDF
588 Letters The Editor of" Flight International" is not necessarily in agreement with the views expressed by correspondents in these columns. Names and addresses of writers, not for publication in detail, must in all cases accompany letters. Brief letters will have a better chance of early publication. The SST and the Sonic Boom SIR,—I very much appreciate your reference to my report "Speed and Safety in Civil Aviation" in the September 5 issue of Flight International under the heading "Supersonic Sanity—1." May I, however, be permitted to object to the first sentence of the note: "Of course the supersonic air liner will come, but it must not be at the expense of develop ments in the fields of minimum operating cost and maximum safety." Although the sentence was not indicated as a direct quotation, the subsequent text could give the erroneous impression that the sentence represents my views on super sonic aviation. This is certainly not so. As follows from my report, I maintain that the safety of the SST cannot be predicted but is likely to prove inferior to that of subsonic aircraft, and also that the SST will be grossly uneconomic, even disregarding sonic booms and cosmic radiation, both of which will have serious economic consequences. Furthermore, I contend that the net gain in the combined time/comfort consideration which can possibly be obtained in the limited range bracket from about 2,000 to 4,000 miles is out of all proportion when compared with the annoyance and even suffering that hundreds of millions of people on the ground would be subjected to, due to the sonic boom in the case of unrestricted supersonic operations. The restric tions necessary to keep sonic-boom annoyance within acceptable limits will, in my opinion, make supersonic aviation most unprofitable even if it were to be heavily subsidized. The indirect consequences of supersonic flight are about as serious as its direct shortcomings. The enormous invest ment and effort needed to develop SSTs cannot but hamper the brilliant prospects in sight of making aviation a really safe, cheap and convenient means of transportation. I do not believe that all these serious effects of supersonic aviation can be eliminated or even appreciably lessened merely because "more and more funds and technical efforts are allocated to supersonics." The sonic-boom problem, for instance, does not seem soluble on the basis of present knowledge and will certainly not be solved in time for cur rent SST projects. In this context, two questions still call for answers:— (1) Why has no research been made (or, if made, results been published) to assess the limits for acceptable sonic-boom overpressures with special attention to those people who have the most need for quietness, in particular sick, nervous and elderly people—as well as light sleepers in general—not least those who have chosen to live in the country in order to enjoy solitude? (2) Why have not the consequences of the inevitable, great deviations from theoretical or average boom intensities (due to focusing and similar effects caused by unavoidable un steady atmospheric and flight conditions) been analysed or even indicated in any published document in which civil supersonic aviation is declared to be feasible? These devia tions are, in fact, much more important than the average boom intensity itself. There is ample evidence that military supersonic aircraft, which are operated so as not to give a higher theoretical boom intensity than some 0.5 to l.Olb/sq ft, often have caused local over-pressures many times greater, resulting in extensive window breakage and other damage to property as well as serious shocks to people. For the indicated reasons, I cannot reconcile myself to the thought that supersonic aviation, as it is at present con- FLIGHT International, 3 October I ceived, is inevitable. It is unbelievable that civil aviation and Mankind would let themselves be rushed blindly into an un wanted, unpredictable and, in all probability, dangerous and interminable development merely because of present-day prestige considerations or the idea that some aircraft indus tries must be kept busy by producing SSTs rather than im proved subsonic aircraft. Those of the readers of Flight International who do not have time to study my full report might be interested to read the review of the main conclusions which was made at the request of The Observer in two articles on August 25 and September 1 this year. They are available from The Observer in a reprint, "The Supersonic Threat." I may also refer to my article "The Case against the Supersonic Airliner," Flight International, April 5 and 19, 1962. Bromma, Sweden BO LUNDBERG The Perpignan Tragedy SIR,—The slow cruising speed of a Viking and DC-3 and the fact that an NDB is a poor directional aid necessitates a 25-mile MSA into Perpignan giving a minimum height of 11,500ft. Since oxygen is required in an unpressurized air craft above 10,000ft one might well ask why operation into Perpignan is permitted at night. Toulouse - Perpignan is 84 miles. Maximum drift error for 25kt wind at cruise TAS of 150kt is 20 n.m. (50kt wind = 39 miles). Maximum overshoot error possible is 26 miles (50kt = 59 miles). Thunderstorms cause winds to shift considerably, so danger with an NDB aid only is con siderable. I would have thought that a safer approach to Perpignan would be to leave Istres tracking out on the VOR and using the Bagur beacon as a track check. After the Cassis Fixer and Perpignan NDB both agree your position, turn into the field. This for unpressurized aircraft must be easier, as there are no mountains below, only sea. London Airport EX-VIKING PILOT [The Jeppesen approach chart for Perpignan notes an MSA of 7,000ft over a 20 n.m. radius and 12,000ft over a 40 n.m. radius. The IAL Aerad approach chart indicates MSA over a 25 n.m. radius by 90° sectors, the stated heights being 10,200ft, 10,200ft, 4,300ft and 5,300ft.—Ed] SIR,—I should like to take issue with you over the word "charter" on page 491, September 19, as it implies that the contractual arrangements covering the flights quoted were a contributory factor in the accidents listed. The Boeing 707 accident at Orly Airport on June 13, 1962 (note my careful choice of words) concerned a national carrier whose main business is schedule operations, and the home base is Orly. The captain and crew were, therefore, doing something they had done more often from that par ticular airport than from any other, yet the first observation in the "circumstances" column is the remark "charter flight"! What possible significance could the contractual arrangements have had in relation to the crew or the accident ? It is just this kind of "statistic" that is seized upon by ill- informed politicians, empowering them to jump on the charter hobby-horse and gallop irresponsibly through the pages of the popular Press, insulting all Independents while adding cement to the schedule wall behind which national carriers with doubtful safety records are only too willing to hide. The main business of the Independents is ITX, which is often erroneously referred to as "charter flying," when it is, in fact, completely scheduled and is defined as such by the Ministry of Aviation. What I consider significant in most accidents is that the area or airfield where the accident occurs is well known to the crews and fulfills all schedule require ments regarding crew familiarization. The answer must surely lie elsewhere. It is my view that accidents should be listed as follows: (1) take-off; (2) climb to cruising altitude; (3) descent from cruising altitude; (4) landing; (5) en route. By far the greatest majority of all accidents happen in the first four categories. The crash zone is, therefore, within 100
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