Building the Warthog. Inside the A-X Flyoff: Rare 1972 Footage of the A-9 and A-10 Discover the intense rivalry behind the U.S. Air Force's A-X program in this rare restored documentary footage, featuring the head-to-head competition between the Northrop YA-9 and the Fairchild Republic YA-10. This video provides a rare look into the development of America's premier tank killer, highlighting the engineering challenges and design philosophies that defined late Cold War aviation. #A10 #Warthog #Avi