The aviator

Front matter

Class Book.

*J

Gopyriglrt>J?.

Contents

CHAPTER PAGE

I. The Aviator as a Machine ...',. i

II. Nerve and Nerves 8

Introduction

After the Wright brothers hit upon the principle of controlling a gliding machine, the progress in aviation was astonishing. Their discovery came at a time when the experience in manufacturing automobiles was available for the development of the airplane. Already, the solution of many of the problems of light and powerful motors, metal alloys, ignition and carburetion were under way. Before the war began, the airplane was a practical machine. During the war, all the great nations developed the invention with a vigor and ingenuity that no other invention ever received in so short a time. As a result, the airplane is a highly perfected machine; each inch of its surface, from the

pitch of the propeller to the lines of the rud-

.

xii INTRODUCTION

der, give evidence of the study put upon it So absorbing was this work that the other factor in aviation, the aviator, came in for comparatively little scientific attention. True, he was featured in fiction and romance, but that did not help his flying. It became evident, as the war continued, that in the art of aviation the operator was quite as important as his instrument. Then each nation undertook the study of her airmen; not with the spirit, nor with the assurance that her engineers studied the planes, but in a hesitating and apologetic way. Nevertheless, it became apparent to every one interested in aviation that the aviator should be understood as well as the airplane. To accomplish this, the machinery governing his conduct must be studied as thoroughly as possible. Here again, aviation is fortunate in being born at a time when the sciences of psychology, physiology and biology have accumulated a great deal of information that bears upon the problems to be

INTRODUCTION xiii

solved. To bring some of this material to the lovers of aviation and to put it in readable form, is the purpose of this book.

Henry C. McComas.

Chapter I The Aviator As A Machine

It IS not uncommon for the pilot to think of the airplane as human, with all of the eccentricities of human nature. The temperamental peculiarities of a gas engine are about as unpredictable as the moods of a coquette. No wonder the mechanic calls it "she." He finds the evidences of a personality there. Turn this idea upside down and we have a new idea. Instead of thinking of the plane as a person, think of the pilot as a machine!

He is a machine. The system of levers which runs from the ailerons does not stop until it reaches his shoulder socket. The cords which swing the rudder continue until they terminate in the pilot's thighs. Both machines suffer from cold, from the changes in the air densities, from prolonged flying and a number of other ills. They are not two machines, they are one. The success of the flight depends upon the combined action of the pair. The airplane was designed to do its work in the air, but the pilot was designed by nature to do his work on solid earth. A comparison of the type of machine Nature has produced

Flying Reptile, Restored from Fossil Remains One of Nature's earliest experiments in aviation.

to navigate the air with the type evolved to move upon the ground shows some very important differences in design. Several million years ago Nature began experimenting with air machines. At that time there were a

AVIATOR AS A MACHINE 3

number of light, agile reptiles who were being badly crowded by the increase of other animals. In their leaps to escape the monsters of the swamps, those who were lightest and who had the spreading membranes, which enabled some creatures to glide, were the ones to survive. Probably the first designs by Nature paralleled those of man, and were gliding machines. Then improvements were made. One of the first models known represents a pretty good type of air machine. The long rudder-like tail-piece probably served both as a rudder and an elevator. Later models shortened this structure and restricted its purpose. Our aeronautical problems were met ages before man appeared and Nature began trying out methods of getting more power in the engine and of lessening the body weight. Shoulder girdles were strengthened and hollow bones with pneumatic attachments were attempted; and met with success. Such birds as the albatross, which is a powerful flier, have the pneumatic system perfected. The hollow bones are connected with aircells, so that the air entering the lungs may also reach the bone marrow. Moreover, the problem of stream-lining was early taken up and solved

A Type of German Monoplane

Showing ingenious efforts to take hints from Nature's experiments.

by Nature in the graceful tapering lines of so many types of birds. Compare the rep-

AVIATOR AS A MACHINE 5

tilian head in the picture with the smooth lines of any modern bird. Notice the beginnings of stream-lining in the body form. German astuteness early saw the numerous hints Nature had for those who were making heavier-than-air flying machines and the German airplanes are more closely modelled along the lines of bird forms than those of any other nation.

Not only is the gross structure of Nature's flying machines unlike that of the types which move on land, but there are many little refinements in structure, which perfect the flying machine. For example, the eye of the bird is brought against a severe pressure in the air when it flies at high speed. Nature strengthens the eyeball and supplies a third lid. A differentiation is made in the eyes of those doing night work. A higher body temperature and a covering of feathers give the bird a natural advantage no human ingenuity has matched. No fore-and-aft level, or side slip device can make the human flier fly as the bird does. No one ever saw a bird fly out of a cloud upside down! No compass will ever take a man across a continent as the instinct takes the bird. By instinct the bird takes off from the ground into the wind; by instinct they fly in a squadron formation, so that they do not interfere with each other. No such endowments are 'given man. He must use intelligence where his aerial competitors use native instinct.

In short, Nature has made one type of machine for moving in the air, another for moving on the surface of the earth. When the latter type is put into the natural element of the former, certain difficulties arise. What these are and how we may meet them are the subject matter of this book.

At the outset, we must consider the very common difficulty which besets the flier. Nature made man with a certain kind of nervous system. It was evolved to make a man feel and act in a certain way whenever he encounters a sudden danger. Can this sort of

AVIATOR AS A MACHINE 7

behavior carry man through the perils of the air? Some attempt to answer that question appears in the chapter *on Nerve and Nerves. The art of flying calls for an activity of the brain and nervous system of a peculiar kind. This is made clear in Controlling the Plane. After these chapters, the various senses, which act as instruments to inform and assist the flier, are explained and discussed. From that we naturally turn to the common enemy of both the pilot and the airplane, Altitude. In this study we find different types of airmen and a description of the method of selecting aviators follows. Finally, some facts which find no place in the study of men as machines are presented in the concluding paragraphs on the Pilot as a Personality.

Chapter II

A PLANE caught fire at 2000 feet up. From the flying field a wonderful flight was witnessed between a flaming airship and a cool-headed cadet. He turned his ship over so the fierce tongues could not lick him. He hung from his fuselage with one hand and brought his machine down toward the ground with the other. The fire burned out. He sought to regain the fuselage and right his ship. She became unmanageable. He worked quickly, skillfully, intelligently. She plunged toward a woods. Still striving to steer and balance her, the pilot and the plunging, rolling ship disappeared among the trees.

These disasters are not often discussed, or deplored, among the cadets. It is all in the day's work. But, months after the man had been laid to rest and the airplane scrap ped, the cadets would speak of the fight. The way to handle a plane when she catches fire is a matter of technique, a scientific question, and it often comes up. This fight never received a purely technical treatment; always this remark entered the conversation somewhere : "It's a shame he didn't get away with it, for he certainly had a nerve"

Two friends bunked together. Both were making excellent headway in flying school work. One crashed and was killed. The other never flew well afterward. His landings were bad and his tight eights looked as though they were both "tight" and tipsy. He was grounded. "It was hard luck," said his friends. "You see it was a case of nerves."

Nerve and nerves! The singular spells self-control, the plural means the opposite. This trick of concealing ignorance with words is an old one. It has its good points. When we come to the end of our information, it is convenient to give the terminal a name.

A great many people reach that place very quickly, when they attempt to understand themselves; then they find comfort in "Nerves."

If we follow the line of reasoning of the preceding chapter, we shall soon discover that there is no necessity for considering a play on words, the final terminal, in an effort to understand self-control ; which is, of course, a form of conduct. Conduct varies in different animals strikingly. Compare the complacency of a porcupine under all circumstances, with the temperament of the jackrabbit. The porcupine is so well protected fate cannot harm him. He saunters into camp unmolested by the dogs. He shows no fear of man. His equipment for sensing danger afar and for flight is not developed at all. Had he nothing but the rabbit's fur he would have to have another nervous system and another type of locomotion. Compare the conduct of such unlike creatures as an opossum and a fox. A danger signal near at hand paralyzes

NERVE AND NERVES n

the former, it galvanizes the latter into swift action. The same menace inspires the same fear in both, but the instinctive reactions are the opposite. An analysis of the organs and their functions, in these two types of animals, would make their conduct intelligible. In one we should find the excitement results in nerve action preventing movement, in the other it stimulates vigorous action. Here, then, is our cue. Nature has endowed different forms of life with different mechanisms for behavior in the presence of danger. Can we not learn something about the conduct of human beings, in the presence of an imminent peril, by a study of such mechanisms?

The physiologists have afforded a new insight into the mysteries of human nature by a study of the organs and functions which operate during the stress of strong emotions. These organs are controlled by the nervous system; so it is necessary to give a brief sketch of the nervous machinery and the way it works, in order to understand such emotions as fears, anxiety, dread, anger, and all the rest of the list which we find credited to the man who flies. Roughly divided, the nervous system may be considered as two systems; one has to do with the action of the person and the other has to do with the action of the internal organs. The former is known as the central nervous system and it consists of three parts; (first, a set of nerves which brings impressions from all of the sense organs to (second) the brain and spinal cord, and (third) a set of nerves carrying impulses out from the brain and cord to the muscles and glands. This is the system which controls our conduct as we live and move among our fellow men and among the objects of nature. Closely allied to it is the autonomic nervous system, but its duty is the control of the vital organs, heart, lungs, stomach, and all the others. It, too, may be divided into three parts; first, a set of nerves which have as their purpose the conservation of bodily resources by controlling the supply of the juices which digest the food, by controlling the movements of the stomach and intestines and by bringing about the cooperation of other vital organs for the purpose of carrying on the upbuilding of the body. This set of nerves is known as the cranial. 1 A second set of nerves has as its purpose the excitation of the vital organs when they are called upon to do extra duty. For example, when we run from some dangerous object, the muscles must have more than their ordinary supply of fuel, so both heart and lungs must work more vigorously. This set of nerves starts both heart and lungs into quickened action before we may begin to run. It is known as the sympathetic nervous system and is much more elaborate than the cranial. Where the latter acts to slow the heart rate, the sympathetic system acts to quicken it. Moreover, it stops the actions of the cranial nerves in secreting juices for digestion and in its movements of the ali-

1 For an excellent description of the autonomic nervous system see Bodily Changes in Pain, Hunger, Fear and Rage, by Walter B. Cannon.

mentary canal. All the energies of a person are needed in the muscles and in the heart, lungs and brain, when there is danger. The work of the stomach and intestines must stop while the other organs are putting forth their best energies to help the muscles in their work. This set of nerves is a sort of war department; when there is any danger it stops all business which is not necessary for the preservation of life. A third set of nerves in the autonomic system is known as the sacral, one of its duties being the control of the sex organs. Between the cranial and the sacral lies the greater and more diffuse set of nerves the sympathetic, and it overrides the activities of both of its neighbors.

From this sketch of the machinery, we may find the explanation for some of the mystifying things we have all noticed in the emotions. Each of these groups of autonomic nerves is accompanied in their actions by characteristic feelings, or emotions. When the cranial nerves are engaged in the delectable work of controlling the necessary juices for the digestion of a good meal, the general sense of well-being, which prevails makes a sharp contrast with the feeling of being "ill at ease" when anticipating some unpleasant encounter. The latter feeling may develop into a genuine fear, or even terror, then none of the complaisance of well-being remains. One cannot even eat his food, much less enjoy it. If it reaches the stomach, it may be ejected, or lie undigested. As an experiment, an animal was fed and then subjected to a period of fright; it was observed that all movements in the stomach and intestines ceased. Many an aviator has made his passenger vomit from sheer fear. Even more conspicuous in the emotional realm are the conflicts between the emotions which arise from the sex life, controlled by the sacral system, and the emotions fear and anger, controlled by the sympathetic system.

It has been found that the work of the sympathetic system is aided in a very remarkable way by the secretion into the blood of adrenalin. Two small glands lie just back of the kidneys, which are known as the adrenal bodies. The substance they secrete passes through the blood-stream to all parts of the body. If an animal is inoculated with adrenalin he shows those symptoms which appear when the sympathetic system is arousing the creature to fly from some danger. The pupils dilate, the hair stands on end, the heart and breathing rates increase. A careful experiment shows that even the tired muscles are refreshed. Adrenalin is a sort of reserve corps which jumps into action the instant there is a danger signal. When the first set of nerves in the central system is affected by some outside danger signal, let us say a curtain on fire, the nerve current passes to the brain, arousing a conscious state. It then passes to the third set of central nerves and starts the muscles into action, but as it does this the cpnscious state affects the mechanical operation of the nervous system. If the fire is really dangerous, the autonomic system is roused by the recognition of the danger. At once the sympathetic system quickens the heart, the breathing, stimulates the adrenal glands, the muscles become abnormally "irritable," the blood leaves the cheeks, it flows to the parte in action. With the general disturbance come the characteristic sensations which we speak of as the "emotion of fear," sensations from the heart, the stomach, the quickened breathing and the tension in the muscles.

This emotion of fear and the physiological activities which accompany it constitute an instinct. An instinct is often called a racial habit, it is characteristic of the human race, it is a genuine part of human nature, it operates automatically; given a certain stimulus, we find ourselves doing certain instinctive things. An unexpected danger, or a sudden, violent pain, will start the racial habit into actions of the kind we have just been describing.

Now we have the materials for explaining some of the mysteries of "Nerves." For example, it is a common experience in learning aviation to be very restless, anxious, perhaps thoroughly scared, during the first few trips when one is simply observing the ship and its behavior. All of these symptoms disappear at once as soon as one takes the wheel and the rudder! Instead of experiencing greater excitement and apprehension, he becomes calmer and feels he has better control of himself. One of several reasons for this is, he is doing something. The whole system is prepared by the excitement of the occasion to do something. If these natural processes making for action are blocked, one has that most distressing experience of fighting against nature. To avoid this, many trainers have their men do something prior to entering a contest, something that enables the organs to act at least mildly when they are urged by Nature to act vigorously. It has been found that the excitement of witnessing a football game by a substitute player definitely increased the blood-sugar, which is needed for active muscles. The same results are found in the anxiety of anticipating college examinations. Excitement calls for action to work it off !

Surely the poor mortal, who prepares for his first flight in an airplane and discovers his knees trying to beat "taps", his complexion like a flag of truce, his heart and breathing misbehaving and that annoying cold sweat, will find consolation in Physiology. No; it is not a "yellow streak" in his make-up, it is just adrenalin and a rampant sympathetic nervous system. Is he going to be any good in the air? That depends upon what his internal machinery does when it gets into action. If the emotion incident to impending danger still arouses excessive actions in his organs, which his efforts do not direct and restrain he will be "too nervous to fly." Often a man has sense enough to know that his machinery, inherited from his ancestors, is not dependable, and that he gets "rattled" when he is excited. Many experiences have taught him not to trust his instinctive actions. Such a man shows courage and good judgment when he leaves aviation alone.

Another trick of the nerves gets its partial explanation here. When a beginner in swimming, rowing, fencing, or any sport is somewhat excited by his new experience he overexerts himself. His motions are too quick and too vigorous. If you began to sail a boat with a little anxiety about its performances, you will remember how hard it was to let the sheet and rudder alone after you had them set for a steady wind. Nature was urging action, your physical ship was cleared for action with boilers hot and steam up. Your teacher made you sit still. Probably you found compensation in squeezing the tiller till your hand was numb. That is what the beginner in the airship tends to do. The instructor often casually remarks, "Don't try to squeeze the juice out of the stick, it's been seasoned." Perhaps it is as well to let the novice squeeze! It uses up some of that surplus energy his system is supplying and may do a little to prevent him from overworking his controls.

The question naturally arises, what would happen if a man were kept in a state of excitement continually, or frequently, and not allowed the action his nerves and organs demand? The answer is given in a comparison of nervous troubles which afflict pilots and observers. The latter break down sooner and to a greater degree than the former. 1 The pilot's attention and energies are occupied with the ship. The observer has his mind freer to note the dangers of the situation. He must also trust the pilot for his safety. If there is an accident, he can do nothing. He must rely on his associate. His attention cannot be diverted from the danger to an active control of the plane.

A pilot once told me that he was surprised to find his companion, who "had a wonderful nerve" give way and cry, "Oh ! God ; oh, dear

1 Anderson, H. G., The Medical and Surgical Aspects of Aviation, p. 116.

God !" as they crashed from about a hundred feet. He declared he had no emotions of any sort, that he felt as clearheaded and had himself as well under control as at any time. He was busy u trying to slap this planet as gently" as he could, and was a little surprised to hear his usually silent companion so vocal.

This leads us into another phase of the subject. When the attention is directed to the controls, the mind is not dwelling on the dangers. When there is no thought about danger, there is no anxiety. The crux of the issue is in the attention. When the beginner gets his hands on the wheel and his feet on the rudder, his thoughts turn to things mechanical and there is little room for ideas of crashes. This, with the efforts to control the ship, dispels the anxieties which will haunt the most intrepid in his trips as an observer. Indeed, there are many pilots, who never know a moment's discomfort, when controlling the airplane themselves, that become actually sick when they ride as passengers. I found in my first flights the tension of the situation relaxed considerably when I ceased speculating on landings and watched the controls, trying to relate movements of the stick to changes in the ailerons.

Self-control, then, is the indirect result of control of the attention. The high-strung, college graduate who knows how to keep his mind on one line of thought and the stodgy, unimaginative fellow, who is never afraid, may both show their "nerve" in danger, one because he concentrates upon a certain line of thinking, the other because his mind is too inactive to entertain anything but what chances to occupy it at the moment.

A man's training in control of his thinking is invaluable in times of danger. The ability to concentrate is all important. Here the difference in the mental traits of men shows itself in their conduct.

The pa^fcof the nervous system in which consciousness is resident, the cortex of the cerebrum, is the most recent acquisition of the human species. It developed during the ages after the lower centers and the cord had reached their development The functions of the old system run back into the remote ages. Those of the newer are not so deep-seated, so fundamental. The old has to do with the most ancient activities, instincts for flight, or self-preservation and the emotions which accompany them. The new has to do with conscious conceptions, with the social ideals, patriotism, honor and the respect of others. It has been suggested that some forms of war neuroses arise from a conflict between these two parts of a man's nervous system, and their duties. Thus, the terrible detonations of the battle naturally arouse the instinct of flight — all living creatures possess the instinct of flight in the presence of very loud, or sudden, noises. The cries, the odors, the scenes of mutilations all arouse the deep instincts of escape from the imminent horrors. Against these impulses stand the ideals of the individual. He thinks of the shame of flight.

He resists the impulses of his nature and holds himself in an unnatural environment. From this conflict comes a nervous break-down which is often miscalled "shell shock." Among aviators this conflict often results in a staleness. The effort to force the brain to endure the long strain of flying over the enemy's lines results in a loss of nerve energy. The brain is fagged. There is a loss of interest in everything. There is no desire to read, to play, or to do anything. Sleep is hard to win, dreams are excessive and distressing. Occasionally delusions appear and haunt the listless wretch. Persistent ideas, or insistent fears beset him. He has overtaxed the most finely developed and adjusted part of his nervous system. If he, or his officers, ignore these protests of nature and force the victim to continue his work, he is surely destined to disaster.

One of the most pathetic notes I have entered into my records is a story of an American aviator, as it was told me by his two chums.

The man was a college athlete of the best type, strong, alert, full of pluck and ingenuity. He kept in the air too long, he grew stale. Then something happened that never occurred before in all his many encounters, an opponent crept upon him unawares. His chums declared the Hun did not get him, it was the long hours in the air that killed their friend, plus his determination to make his constitution bear the unnatural strain. In trying to select aviators, one of the first interests was whether he had the nervous system to stand the strain of great excitement and whether he could keep it in control.

As might well be expected there are some men who give way under the strain more easily than others. Dr. Gotch * found that 167 out of 200 patients at the Royal Air Force Hospital, Hempstead, gave evidence of nervous instability either on the mother's or father's side of the family, or on both sides. "The worst cases almost invariably showed some." Dr. Gotch followed up his patients' family histories, inquiring into their nationalities "particularly as to any Celtic or Hebrew blood, " also noting the cases of alcoholism, of eccentricities, the "attitude toward worries and troubles of all kind." Slight defects in the nervous organization of a man may never show in ordinary -civil life. He may live his three score and ten years quite like anyone else, "but in the case of the flying officer this is different. The experiences he daily undergoes whilst on war-flying involve the greatest strain on his nervous system that is possible in any 'human being, and it is reasonable to suppose that any slight kink in his hereditary nervous disposition might give way." In the family histories of those who become "Star Fliers" there is nothing for debate.

Not only does a "kink" in the nervous make-up which comes down the family line constitute a flaw which may result in a break, but a former break-down may leave a weakness for years undetected. One never knows where a weak link lies until the breaking strain is brought to bear. A number of strange cases come to light in the psychiatrists' records. 1 A rather typical example is as follows: A lad of nine set fire to his sister's hair with a Roman candle and burned his hand. He was extremely upset by the shock and suffered nightmares. It passed as an incident in childhood. Twelve years later, as a balloon observer, he took to his parachute when the balloon was threatened. Again the haunting dreams, which finally took the form of burning his home. He became a "debility" case. It was with difficulty and only after questioning that he recalled the incident in boyhood. Nevertheless, no psychiatrist, who had experience with this sort of trouble, will doubt the connection between the two experiences. It is necessary to know whether any of these childhood episodes, whose results are so often concealed, have occurred in the past life of the man who gives way to the strain; especially

x Op. cit. p. 1 1 a.

when the break-down seems out of proportion to the apparent cause.

Often the flier has nothing in his heredity, or his early history, to indicate a weakness. The trouble comes from strain plus some emotional shock. The two are too much for him. The cause may be mental, the effect is instability and heightened excitability of his nerves. The%e disorders affect centers controlling his heart, breathing, blood-pressure and even his reflexes. He cannot concentrate his attention, his memory is poor, he lacks interest and becomes sleepless, restless and irritable. Such symptoms point to disturbances in his higher centers.