About This File
X-Plane 10 Northrop YA-9. The Northrop YA9 was a prototype attack aircraft developed for the United States Air Force A-X program. The YA-9 was passed over in preference for the Fairchild Republic YA-10 that entered production as the A-10 Thunderbolt II. The Sukhoi Su-25 (NATO code name: "Frogfoot"), also made for a ground attack role, flew three years later and has several design similarities to the YA-9. Documentation included. By Billy Bargagliotti.