Founded in 1963, the Allied Pilots Association—the largest independent pilot union in the U.S.—is headquartered in Fort Worth, Texas. APA represents the 10,000 pilots of American Airlines, including 649 pilots not yet offered recall from furlough. The furloughs began shortly after the Sept. 11, 2001 attacks. Also, several hundred American Airlines pilots are on full-time military leave of absence serving in the armed forces. The union's Web site address is www.alliedpilots.org. American Airlines is the nation's largest international passenger carrier and fifth-largest cargo carrier.