Many contributions of value to the general theory and practice of training for flying were made by these enthusiastic young men who toiled unceasingly over the problems set by our training fields. One young lieutenant, while studying the causes of airplane accidents and trying to find some means of preventing them, worked out a series of exercises which reproduce the positions that must be taken in advanced flying and so enable the cadet early in his work to find out whether or not he is physically unfit to undertake acrobatic work and also give him a measure of preparation for it. Experiment showed that the motion picture film had possibilities for the flying instructor and when hostilities ended it had been drawn into the system of training and was beginning to be used to hasten and to make safer the cadet’s progress. Sitting safely in his chair, he watched whirling horizons, skies and landscapes, pictured from an airplane going through one acrobatic performance after another, noting the varying appearances of the pictures and his own sensations, and so having his nervous system educated in advance for what he would have to undergo, learning in time whether or not it would unduly affect him and gaining quickly and without danger valuable experience. An important development, worked out and used at American flying fields, was a series of tests of the flier’s physical ability to endure high altitudes. Observation showed that accidents sometimes were the result of inability to endure rarefied atmosphere and by placing the student in a tightly closed room, gradually exhausting the oxygen and noting his reactions it was speedily determined whether or not it was safe for him to attempt high flights, either with or without a device for supplying him with oxygen.
The flight surgeon, specialized out of the army medical officer, was one of the early developments of training for air warfare and soon also there appeared, first devised and used at an American field, the flying ambulance, which enabled him and his assistants to go at once to the help of an injured airman, give him first aid and bring him back in the fuselage of the ambulance plane to the hospital. The end of hostilities saw at least one flight surgeon at every aviation training field in this country and several at each of the large ones. And there had been established a division of flight surgeons for which medical officers could receive a special course under the direction of the Medical Research Board of the Surgeon General’s Office. The flight surgeon’s duty was to keep every aviator under observation, to examine each one physically before and after flying, to note the effects of flight, especially at high altitudes, to determine how frequently he should fly and to discover whether or not he had physical peculiarities which would unfit him for any special kind of air service. To aid in this work, which was producing remarkable results in the way of both efficiency and safety, there had been established at many of the flying fields research laboratories which worked out new tests and special and ingenious apparatus for using them and made examinations and observations of the airmen in training. Associated with the work of the flight surgeon was that of the athletic instructors who, toward the end of the war period, were appointed for service at the flying fields. They were former college athletes and athletic instructors who had received special training for the work of keeping the student aviators in the best possible physical condition.
These phases of the system of training that was worked out at American fields aimed to lessen the chances of accident and to gain greater speed and efficiency in the progress of the cadets. Throughout the war period the United States made a much greater effort to lessen the casualties of training than did any other nation. A longer period of work under dual control and more knowledge and skill before the cadet began solo flying were demanded by our system of training than other nations thought necessary. This and other provisions for the safety of the cadets made our training casualties less than half those of any other nation among our war associates. The record of American flying field casualties showed 278 fliers killed in training, an average of one to each 236,800 miles flown by cadets.
The system of training had not only to produce men for work in the air. It had also to train large numbers for a great variety of work necessary to sustain and coöperate with the flying fighters and observers. In addition to unskilled labor, fifty-two trades and occupations are essential to the aviation service and men had to be either wholly or partially trained in each of them. At first, in order to secure skilled men with the utmost speed, mechanics were sent in detachments to a great number of factories where special training was given them and afterward, as experience began to disclose what would be needed, carefully worked out courses of training were established in nearly a dozen different schools. Government schools giving thorough training, in operation at the end of the first year of war, were graduating 5,000 mechanics every three months. Aerial photography had developed during the war to an exact science, but when we entered the conflict very little was known about it in the United States. Instruction in it was of a threefold character, for observers had to learn how to operate cameras in an airplane, intelligence officers on the ground had to be instructed in the interpretation of the results and enlisted men to be taught to do the developing, printing, and enlarging and to keep the equipment in condition. Schools for training in all these things soon produced the necessary instructors for the flying fields where training in aerial photography was given.
It was a complicated and difficult problem that the United States faced when it undertook to work out a system of air training while it was training the men for air service. But within a year and a half it had evolved an efficient system that set higher standards than did other nations and also better safe-guarded the lives of the men in training, and while doing this it had sent overseas 4,776 trained flying officers, had as many more at home fields, and had in training at home more than 5,000 cadets, of whom nearly half were in advanced stages of the work. In the final test of service at the front the men who had been trained by that system received for their ability, skill and deeds the heartiest and highest praise.
CHAPTER XVIII
THE BALLOON CORPS
The division of ballooning gave important service, although it also had to be developed from a condition of little consequence. The few balloons of all types possessed by both the Army and the Navy were a small fraction of the number that would be needed. The balloon force consisted of eight officers and sixty enlisted men. The only school for ballooning had been rescued from complete abandonment a few months before we entered the war, but it had accommodations for only fifteen officers and 400 men, while its equipment was both obsolete and meager. A program of expansion in the balloon service was instituted and carried out that, in proportion, was comparable with that of the airplane service. Within a year and a half both Army and Navy were well supplied with all of the various types of balloons and up and down the coasts of the United States and of France and over our troops in the battle lines floated observation balloons manned by eagle-eyed watchers, dirigibles were aiding the coast patrols of both shores of the Atlantic and helping to escort troop and supply ships through the danger zone, kite balloons were giving constant and valuable service and balloons for the scattering of propaganda on and behind the enemy lines were undermining the morale of troops and peoples.
For training purposes the one existing school was modernized and enlarged and others were opened, great rubber plants revived the balloon making art, and at the end of hostilities the Army had over 1,000 and the Navy 300 balloons—dirigible, semi-dirigible, supply, target and kite—and the Balloon Corps of the Army contained more than 700 fully trained officers and 16,000 enlisted men, organized into 100 companies, of which 25 were in the battle zone. Plans were then under way to continue the expansion at an increased rate, for developments at the front were constantly making more useful the balloon of every type. To comply with this overseas need arrangements had been completed to increase the Balloon Corps by 1,200 officers and 25,000 men.
One of the most important scientific developments of the war was the result of the endeavor of the American Air Service to find a non-inflammable gas for balloons. Investigation and experiment by the United States Bureau of Mines found a new source for helium in a natural gas field in the Southwest, from which it could be produced so cheaply as to make possible its use for this purpose. Up to that time no more than a few hundred cubic feet had ever been obtained and its value was $1,700 per cubic foot. When the war ended 150,000 cubic feet of helium for balloon inflation had been shipped and plants were under construction that would produce 50,000 cubic feet per day at a cost of about ten cents per foot. As a helium filled balloon could not be destroyed by incendiary bullets it would be comparatively safe from enemy attacks and could carry on over the enemy lines operations of the greatest importance. Both the American and British governments had perfected their plans, when the armistice was signed, to use many dirigibles thus filled in air attacks from which immense quantities of bombs would have been dropped over strategic points in Germany.
Because of the assurance of safety which this non-inflammable gas gives to balloon operations, the usefulness of all balloons, but especially of the dirigible type, has been enormously increased and a new era opened for their service. Working upon the problem of making it possible to send propaganda balloons upon long journeys over the enemy’s country, the meteorological service developed ingenious types of balloons that did remarkable work of that kind during the last months of war and, in addition, give promise of very great usefulness for the days of peace.