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Aviation History
1914
1914 - 0317.PDF
MARCH 21, 1914. 2. Failure of Material.—Th* sudden failure of some essential part due to a flaw or some other fault in material, whether it be of the engine or some structural part of the aircraft, is, I fear an instance of the occasional fallibility of all sorts of mechanism and material, and one that it is impossible to absolutely guard against Accidents from this cause are, happily, of rare occurrence 3. Faulty Repairs or Alterations Imperfectly Carriea'.Out have unfortunately, caused loss of life on more than one occasion Lessons to be Drawn and Remedies Suggested.—\\w\™ now considered the various causes which originate accidents, and also in a geneial way their relative importance in the production of accidents, I will now turn to the lessons to be learnt from the accidents and their causes, and the means to be taken in order to avoid as far as possible their recurrence. I have purposely avoided referring to any names in connection with the subject of the causes of accidents, as my remarks are intended to be general, and no particular purpose would be served by indicating any particular instance, more especially since in nearly every case of accident some blame may be attributed, or thought to be attributable, to individuals, whether pilots or others. I should be extremely sorry that any statement I might make should be the cause of pain to anyone interested. For convenience I will again take the causes of accidents in the order in which I have scheduled them, and as far as possible suggest the natural remedies or precautions which should be taken to prevent them. A. 1. Training of Pilots. I have already called attention to the fact that accidents of a fatal nature to pupils under tuition are rare. This in itself shows that the various schools where aviation is taught exercise great care in preventing their pupils incurring unnecessary risks, it being obviously to their own benefit and also to that of their pupils, actual and prospective, that accidents, from whatever cause, Should be as few and far between as possible. 2. Hazardous Flying, &c. Common sense on the part of pilots themselves is the best safeguard against accidents from these causes. No regulations, whether issued by the Royal Aero Club or even by the Government in the form of an Act of Parliament, will pre vent a man doing foolish acts ; if, as a result, he is killed, he has paid the extreme penalty of his foolishness. If he is injured only, he may be punished by law, but this will not disturb him so much, probably, as the knowledge that the accident was entirely his own fault and that he will not get any pity from others. Nor does he deserve any on that very account. 3. Accidents occurring from momentary loss of control under an entirely different category and would appear to call for improved designs, in which such possibilities as feet slipping off bars or pedals, or hands slipping from levers or wheels, or the pilot slipping bodily out of his seat, are guarded against. I have already referred to the possible effect of the latter. One method of guarding against this is in everyday use with some pilots. I refer, of course, to the employment of a broad band or strap securing the pilot into his seat ; such a band or strap is and must be fitted with some reliable quick-release device, whereby the pilot can instantly release himself with one hand when necessary. It is curious that whilst some pilots advocate very strongly some such method of securing themselves in their seat, other pilots are just as strongly against it. Probably there is a certain amount of sentiment about this ; men do not like being tied up or locked in under any conditions and in any place, even when they know that they can immediately release themselves. An impartial examination and consideration of the accidents which we have investigated leads me to the opinion that the advantages of the belt to secure the pilot in his seat more than counterbalance the disadvantages. In no less than six fatal accidents out of eighteen, where the belt was not used, its employment might conceivably have saved the pilot's life, and might in more than one of these instances have enabled the pilot to regain control, and avoid any accident occurring at all. It is quite clear, I think, that pilots generally could not be compelled, at the present time, to strap themselves in to their seats ; neither could such a law be made until the great majority agree that it should be done owing to it having been clearly proved that the increased degree of safety thereby obtained justified compulsion. What can be done now is merely to keep records and compile statistics on the subject for the benefit of those concerned. I would only add that apart from the question of loss of control following upon losing their seat, pilots have been killed by being thrown forward violently against a strut or other portion of the structure on the aircraft striking the ground. This could hardly have occurred had they been secured to their seats ; on the other hand, it may be argued that a pilot may stand a better chance of escaping with his life if, not being strapped in, he jumps or is thrown clear of the aircraft on its striking the ground. In any case there can be no valid objection to the use of a safety helmet, which, forming as it were a cushion or buffer between the head and the object struck, does, in effect, convert a blow, which would in most cases be a very violent one, into a push. If the same lAJCHTj ingenuity that has been devoted to shock absorbers for landing skids, &C., were applied to contrivances, the simpler the better, for reduc ing the shock of impact on the human body in the case of a fall, by spreading it over a longer time, it is my opinion that more lives would be saved than at present is the case. 4- The Physical Fitness of Pilots. Though sudden illness cannot, of course, be entirely prevented, still the instances when it occurs will be very rare. I think everyone will agree that no pilot is justified in taking up an aircraft when he is in bad health or recover ing from a serious illness, unless he has taken a medical opinion on his condition, and this is to the effect that he is fit to fly. The matter is even more important if he contemplates taking a passenger or passengers up with him. I am strongly of opinion, which I know is shared by others, that no one who is not sound in body or limb should be permitted to learn to fly at all. Such a person who becomes a pilot is always a potential source of danger to himself and others. No real hardship could result if flying schools would only accept as pupils those who had passed a medical examination, with a view to establishing that physically they were fit for such work. The examination should be a special and thorough one, such as a candidate for the Army or Navy or Civil Service has to pass. The question of the fitness of pilots who have already got their certificates is more difficult to deal with effectively. When pilots are employed in carrying passengers, as is now the case to a very limited extent, but may in the near future become widely spread, it seems to me that the public will insist on such precautions being taken in this direction as will ensure their safety being reasonably safeguarded. The fifth cause of accident, viz., violent atmospheric disturbance overcoming the pilot's controls, is one which the human being cannot govern, and accidents from this cause cannot, therefore, be entirely prevented. It is quite clear, however, that they are rapidly being minimised by the use of more powerful engines and by the increasingly greater skill of the pilot, who, it would appear, is now able to right his aircraft from any conceivable position into which it may have been forced, provided he has sufficient vertical space in which to carry out the manoeuvre. I now come to the causes of accident enumerated under the second heading, B :— The first of these, namely, the failure of some essential portion of the engine or aircraft owing to the design of such part having been wrongly calculated or calculated on insufficient data to ensure the necessary strength to resist the stresses to which it is put, is a fault that, a few years ago, might have been pardonable owing to the want of technical and scientifically accurate knowledge, but at the present time there is no more excuse for any aircraft being built without the proper calculations having been made to ensure a sufficient factor of safety of all the parts under the conditions of flying than there is for the construction of a bridge, ship, gun or any other structure being built in a similar manner. To build an aircraft by the so-called rule of thumb, and by that alone, is to court disaster, and it is a melancholy fact that valuable lives have been lost by the failure of such aircraft when flying. The responsibility for sufficient strength in the design is a grave one, and at the present time rests entirely with the designers and constructors of the aircraft, except in the case of aircraft supplied to the Government, in which case the approval of the design, if such is approved by the authorities, shifts a certain amount of the responsibility on to their shoulders. If aircraft become common, as some people think they will be in the near future, it is quite possible, and, indeed, desirable, that their design and construction should be investigated and approved by some specially appointed authority before they are put into service. 2. Choice and Testing of Material. As regards the second cause of accident, viz., the failure of parts owing to flaw or irregularity in material, the only remedy, and even this is not an infallible one, is care in selection of suitable material for the purpose, and the taking of tests to ensure uniformity. Also, and this is an all-important matter in the case of the alloy steels in vogue to-day, the proper thermal treatment. No failure of material, it must be remembered, occurs without some good reason, upon which careful investigation in most cases throws a light, and this enables the particular cause of failure in the same part, and under the same circumstances to be avoided. The third cause of failure, viz., that due to repairs or alterations not having been properly carried out, or to want of adjustment, or securing of parts after adjustment, is one for which the remedy is so obvious as hardly to call for remark or suggestion. The onus lies with the owners of the aircraft to see that no pilot is allowed to fly an aircraft unless it is certain, so far as can be ascertained by a careful examination made by a really competent man or men, that not only is the aircraft in a safe condition, but that the engine is working normally. If this had been insisted upon, at least two fatal accidents would not have occurred in the manner and when they did. 3*7
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