In 1986, an F-106 of the Florida Air National Guard's 125th Fighter-Interceptor Squadron encountered a Soviet Tu-95 "Bear" bomber off the Florida coast. It was a routine encounter for this Air National Guard squadron, and symbolizes a quarter-century of Air Guard participation in the defense of the United States. In 1953, Air National Guard fighter-interceptor units took on an air defense alert mission, intercepting unidentified aircraft flying into American airspace. Air Guard pilots and aircraft stood alert 24 hours a day. This mission grew each year, and by 1965 the 22 Air Guard fighter-interceptor squadrons flew 30,000 hours and completed over 38,500 intercept sorties. The Air Guard's role in the air defense mission continued to expand; in 1988 the Air National Guard provided 86% of the Air Force units assigned to air defense. For nearly four centuries the National Guard has defended America. The 159th Fighter Interceptor Squadron, 125th Fighter Interceptor Group, Florida Air National Guard continues the Guard's traditional mission.