quality:correction, information:extraction
Henry Harley "Hap" Arnold was an American general officer holding the ranks of General of the Army and later, General of the Air Force. Arnold was an aviation pioneer, Chief of the Air Corps (1938–1941), commanding general of the United States Army Air Forces, the only United States Air Force general to hold five-star rank, and the only officer to hold a five-star rank in two different U.S. military services. Arnold was also the founder of Project RAND, which evolved into one of the world's largest non-profit global policy think tanks, the RAND Corporation, and was one of the founders of Pan American World Airways. Instructed in flying by the Wright Brothers, Arnold was one of the first military pilots worldwide, and one of the first three rated pilots in the history of the United States Air Force. He overcame a fear of flying that resulted from his experiences with early flight, supervised the expansion of the Air Service during World War I, and became a protégé of then Brigadier General Billy Mitchell. Arnold rose to command the Army Air Forces immediately prior to the American entry into World War II and directed its hundred-fold expansion from an organization of little more than 20,000 men and 800 first-line combat aircraft into the largest and most powerful air force in the world. An advocate of technological research and development, his tenure saw the development of the intercontinental bomber, the jet fighter, the extensive use of radar, global airlift and atomic warfare as mainstays of modern air power. Arnold's most widely used nickname, "Hap", was short for "Happy", attributed variously to work associates when he moonlighted as a silent film stunt pilot in October 1911, or to his wife, who began using the nickname in her correspondence in 1931 following the death of Arnold's mother. His family called him Harley during his youth, and his mother and wife called him "Sunny". His West Point classmates called Arnold "Pewt" or "Benny" and his immediate subordinates and headquarters staff referred to him as "The Chief".