By November 11, 1918, the Air Service both overseas and domestically had 195,024 personnel (20,568 officers; 174,456 enlisted men) and 7,900 aircraft, constituting five per cent of the United States Army. 32,520 personnel served in the Bureau of Aircraft Production and the remainder in the Division of Military Aeronautics. The Air Service commissioned over 17,000 reserve officers. More than 10,000 mechanics were trained to service the American aircraft fleet. Of aircraft manufactured in America, the de Havilland DH-4B (3,400) was the most numerous, although only 1,213 were shipped overseas, and only 1,087 of those assembled, most used in observation units. The facilities of the Air Service in the United States totaled 40 flying fields, 8 balloon fields, 5 schools of military aeronautics, 6 technical schools, and 14 aircraft depots. 16 additional training schools were located in France, and officers also trained at three schools operated by the Allies.