I remember that transition in Tucson. Had both A-7's and A-10's flying out of Davis Monthan and F-4's from Luke out of Phoenix. They were trying to phase out the A-7 as a ground attack plane and replacing it with the A-10. The A-10 flying all over in southern Arizona was a common sight in the late '70's along with the O-2's. Another cool airplane. Remember when the Thunderbirds used to have an airshow which seemed like every year at Davis Monthan too? T-38's back then ('73-'82).