In time, the use of the two-engine bomber led to the development of attack aviation. This was built around very fast, two-engined planes which could carry both bombs and guns. These medium bombers were to be used to attack targets of medium range with both bombs and guns. They were to be used to destroy enemy troops, transports, and gun emplacements. In the few years of World War II, attack bombers were developed from comparatively slow planes to ships with the speed of fighters. They are capable of carrying more than a ton of bombs, and of mounting cannon and as many as fifteen machine guns. With the establishment of a definite policy of air strategy, plans were worked out for the training of personnel to man and service our fighting planes. The training plans set up in the early twenties are essentially the same as those in effect at the present. The system consisted of two training schools, Primary and Advanced. In the Primary School cadets received their preliminary flight training and studied construction of planes, radio, weather observation, and other technical problems concerning flight. The qualities shown by the cadets in the primary training helped to determine the branch of combat aviation for which they were best fitted. At the Advanced School, cadets were trained in larger and more powerful airplanes and received instruction in gunnery, formation flying, cross-country flying, and night flying. Graduates of the Advanced School received their wings and, by joining tactical units, completed their training as members of regular service squadrons. In 1928 all Army air training activities were consolidated at one great training center at San Antonio, Texas. This great headquarters for the training of United States Army airmen was dedicated in June, 1930, as Randolph Field, in memory of Captain William M. Randolph. Captain Randolph, a native of Texas, had lost his life in an airplane crash a few years before. It was fitting that the first great Army aviation training program was under the direction of Brigadier General Frank P. Lahm, the Army’s pioneer aviator. [Illustration: CURTISS A-18 _FALCON_ THE ARMY’S FIRST TWO-ENGINED ATTACK PLANE. DOUGLAS A-20 _HAVOC_ FAST, DEADLY WORLD WAR II ARMY ATTACK PLANE. DOUGLAS A-26 _INVADER_ THE ARMY’S 1945 ATTACK PLANE, THE FASTEST AND DEADLIEST PLANE OF ITS CLASS IN THE WORLD.] SUPER-FIGHTER In the Pacific American fighters dropped down from 25,000 feet, screamed across an enemy airfield, guns blasting, and indicators showing a speed of over eight miles a minute. If the Japanese had not been “dug in,” they probably would have been sucked into the planes’ airscoops. Later one of the pilots expressed the sentiments of the entire raiding group when he said, “It’s a wonderful feeling to watch that air speed indicator climb. It makes you feel that nothing on this earth can catch you.”