This division of responsibilities and functions gave a clearer conception of the unique duties of the Air Service in production of planes and training of pilots, and is significant, too, of the many tactical reasons which made it imperative for England and France to establish separate and independent air services. The end of the fiscal year found this problem of higher organization one of the most important to be faced. An early defect discovered in the reorganization developed when there appeared to be inadequate liaison between the Bureau of Aircraft Production and the Division of Military Aeronautics. One was responsible for the production of planes, the other for their operation and military efficiency. The method of selecting a type to put into production and the final decision whether any plane produced was suitable for its military purposes or not, was undetermined. The situation of two sets of officials with equal authority in their respective fields of action, neither responsible to the other, at once demonstrated that neither could be held for the final production of an acceptable plane for the front. This was partially obviated by an agreement between the Division of Military Aeronautics and the Bureau of Aircraft Production that the types of plane to be put into production must first be mutually agreed upon, and that before a plane could be sent to the front it should be given a military test and accepted by the Division of Military Aeronautics. But considerable time was lost before this policy was definitely arranged, a policy which might easily have at once been established by a unified department. The personnel side of the air service, including the selection, training, organization, and operation of the flying forces, developed within the fiscal year 1917-18 into an educational system on a scale infinitely larger and more diverse than anyone had anticipated. Teaching men to fly, to send messages by wireless, to operate machine guns in the air, to know artillery fire by its bursts, and to travel hundreds of miles by compass, teaching other men to read the enemy’s strategy from aerial photographs, and still others to repair instruments, ignition systems, propellers, aeroplane wings, and motors, has required a network of flying fields and schools, a large instructional force, and a maze of equipment and curricula. None of this, practically speaking, was on hand at the outbreak of the war, neither fields, instructors, curricula, nor, more serious than all, experience to show what was to be needed. This country had never trained an aviator sufficiently to meet the demands of overseas aerial warfare and had not the slightest knowledge of the instruction necessary for radio, photography, or enlisted personnel. Consequently, the first men largely taught themselves before teaching others, and experience led on from one course to the next.