At its new base at Youngstown, the 166th Fighter-Interceptor Squadron was re-equipped with F-51H Mustangs which the squadron flew until 1954 when the 166th received refurbished F-80A Shooting Stars that had been modified and upgraded to F-80C standards. With the F-80s, the squadron began standing daytime air defense alert at Youngstown, placing two aircraft at the end of the runway with pilots in the cockpit from one hour before sunrise until one hour after sunset. The squadron only operated the Shooting Star until January 1955 when the 166th received F-84E Thunderjets that had returned from wartime duty in Korea.