FlightGlobal.com
Home
Premium
Archive
Video
Images
Forum
Atlas
Blogs
Jobs
Shop
RSS
Email Newsletters
You are in:
Home
Aviation History
1914
1914 - 0316.PDF
MARCH 21, 1914. LESSONS ACCIDENTS HAVE TAUGHT.' By COL. H. C. L. WHEN I was asked some six months ago to contribute a paper to this Society dealing with the lessons to be learnt from the study of the causes of accidents when flying, I agreed to do so because it seemed to me that a discussion upon this subject could not fail to be of interest and advantage to pilots, constructors, and others by bringing before them in collective form the accidents, preventable and otherwise, which have happened, and in particular those which have been investigated l>y the Accidents Investigation Committee of the Royal Aero Club, on which your Chairman of Council, Gen. Ruck, and several other Fellows and Members of the Aero nautical Society are very useful workers. The Work of the Accidents Investigation Committee.—\ would here remark that the Accidents Investigation Committee was formed in the early part of 1912, and that the first accident it inquired into was one which happened at the Brooklands Aerodrome on May 13th in that year. Since that time, and up to the present date, eighteen other fatal accidents—one of which was an accident to a spectator- have been investigated, and reports upon them issued by the Royal Aero Club. With a view of obtaining as wide publicity as possible, these reports have been sent to, and published by, the technical and lay Press ; and, moreover, copies have been supplied to the Home Office, Admiralty and War Office, at the request of these departments of the State, all of whom have, in one way or another, rendered the Committee great assistance, and upon more than one occasion have expressed their appreciation of its work. The Collection of Data after Accidents.—It may be opportune at thu point to impress upon my audience the difficulty that exists in ascertaining the exact causes of accidents to aircraft. Where the accident is immediately attended with fatal results, it is obviously impossible to obtain the evidence of the principal actor or actors in the tragedy, and even where the accident is not fatal, but only results in injury, as is well known, there is generally a loss of memory on the part of the victim, not only of what occurred after the accident, but of what took place before it, which makes such evidence very unreliable. Again, the evidence of spectators has to be sifted with the very greatest care and caution. The appearance of an aircraft in the air is, from its nature, deceptive, and its exact aspect, position and direction is very difficult to appreciate, even to the most expert in such matters, and in very few cases indeed can conclusive direct evidence be obtained. The evidence of the un skilled spectator is more often than not obviously incorrect and worthless. It is of prime importance, too, that when an accident occurs, the portions of the wreckage should only be disturbed so far as to allow any human beings to be removed, and even then any portions disturbed from their places should be as soon as possible restored to their original positions. The great importance of this mltiel been reco8nised by the authorities at the Home Office, who have issued instructions to the police throughout the country that in the event of an aircraft accident occuring, the wreckage and 81te. *re to •* guarded, and no interference permitted until the Accidents Investigation Committee or its representatives have examined it. The Scope of the Paper.—I have not attempted in this paper to discuss the causes of accidents which have occurred since the art of flying was first discovered, or even the accidents which have occurred all over the world since flying became a practical possibility and comparatively common, for the reason that in only a few isolated cases has any complete investigation been made as to the cause of any accident in this or any other country until the Accidents Investigation Committee commenced its work. Apart from this, I think I shall be able to show satisfactorily that the causes which nave originated the accidents which have been inquired into by the above committee happen to cover the whole ground as far as one can judge. The Classes of Accidents.—The causes of accidents may be divided into two classes :— A. Those due to the pilot. B. Those due to faulty design or to mechanical failure of some portion of the aircraft. Under A may be classed :— I. Want of sufficient knowledge or skill in flying : errors of judgment. b X Attempting hazardous feats or taking unwarranted risks in flying. 3. Momentary loss of control, such as, for example, the accidental revising of hand or foot controls, and not regaining them in sufficient time. 4. Complete loss of control due to sudden seizure, loss of con sciousness, &c. ,i*?¥? ™*d ^fo™ t!?e A,e,r,?°»»'>cal Society of Great Britain, at the Royal United Service Institution, Whitehall, S.W., on March 18th, .914. HOLDEN, C.B., F.R.S., F.R.Ae.S.. 5. Loss of control owing to atmospheric disturbance, a violent 316 gust of wind, for instance. Under B may be classed :— # 1 Dangerous and inherent instability due to faulty design.— Failure of" some essential portion of the aircraft owing to fault in design, insufficient strength having been provided to meet the stresses that the part or parts might be subjected to in the air. 2. Failure of some essential part due to flaw or irregularity in the material of either engine or other part of the aircraft. 3. Failure due to repairs or alterations not having been properly carried out, or to fittings, such as bolts, nuts, screws, &c, having worked loose which had not been tightened up or otherwise made secure before the aircraft left the ground. 4. Fire caused by leakage of pipe carrying petrol, or of tank, the petrol being lighted by spark or flame from the exhaust. This may occur in the air, but it is more likely to take place owing to breakage of pipes or tank when an aircraft strikes the ground. The above comprise, so far as my experience goes, all the various causes to which the accidents to aircraft are primarily attributable, and it will be readily seen that many of them can be guarded against more or less effectually, if not entirely prevented, by suitable precautions being taken. The Causes of Accidents Examined.—Taking the causes seriatim : A. 1. Wanl of Sufficient Knowledge or Skill. It is clear that this is not the most frequent cause of accident with fatal results, or more pupils and learners would have been killed than skilled pilots. Such is, however, not the case ; indeed, it is surprising how few aviators have met with fatal accidents during such time as they were learning to fly, i.e., during the period before they have obtained ' their pilot's certificates. Errors of judgment have, however, caused a number of fatal accidents, through side-slips, over-banking and diving too steeply when close to the ground, and over-estimating the speed of the aircraft. 2. Hazardous Flying. There is little to be said in favour or in justification of taking unnecessary risks and indulging in what may be termed dangerous flying, especially if close to the ground, when a slight miscalculation or error of judgment may involve the pilot in a disaster. It is hardly conceivable that an expert pilot should be so foolish as to jeopardise himself in such a manner. 3. Momentary Loss of Control has, unfortunately, caused more than one fatal accident, and is one of those things that may happen to any pilot, however experienced he may be. Instances have occurred from time to time of control being temporarily lost in this way—luckily without fatal results—as, for example, in the Circuit of Britain last year. In most designs of aircraft the elevator control is so arranged that if the pilot, when diving steeply, should slip forward in his seat on to the controls, the effect would be to make the aircraft dive more steeply still, and so render it still more difficult for the pilot to right his machine. As a matter of principle, it would appear better to arrange the elevator control to work in the opposite manner, i.e., to reduce the angle of descent instead of increasing it under the above circum stances. Unfortunately, it is late, perhaps too late in the day to make any alteration in this direction, even if considered desirable, owing to the number of those who are accustomed to the present system. 4. Physical Failure of Pilot.—There has been one instance where loss of consciousness, owing to the pilot being in such a state of health that he was unfit to fly at all, caused his death, and in more than in one other case this has been, with good reason, the suspected cause of the accident. 5. Violent Gusts or other Atmospheric Disturbances have caused accidents which have terminated fatally owing to the pilot losing control, but generally only when the aircraft has been comparatively close to the ground and control could not be regained in time. We now come to the causes which I have classified under the heading B:— 1. Faulty Design has in the past undoubtedly caused unnecessary loss of life ; want of knowledge as to the magnitude of the forces which had to be resisted, the stresses to which various portions of the structure were subjected, and generally the conditions under which the aircraft flew, was responsible to a great extent in former days for the failures. Design and construction are now, however, tnanks to the practical experience and scientific study of the problems involved, rapidly becoming exact sciences, and except in isolated instances of experimental machines, we may expect failures from bad design to become rare.
Sign up to
Flight Digital Magazine
Flight Print Magazine
Airline Business Magazine
E-newsletters
RSS
Events
