In 1967, the Air Force went to industry for the Attack-Experimental (A-X) program, a new close air support to replace the A-1 Skyraider. The two contenders were the Northrop YA-9 (which bore a strong resemblance to the Sukhoi Su-25 developed later) and the Fairchild Republic YA-10. The YA-10's winning design embodied survivability, boasting that it could fly with one engine shot out, one of the two tails blown off, and 1/3 of one wing missing, and still bring its pilot home. Throughout its early career, skeptics scoffed at these claims, but in combat over Iraq, this capability was not exaggerated!
Even after proving itself in Desert Storm, Operation Enduring Freedom and Operation Iraqi Freedom, some Air Force senior staff wanted to retire the A-10 in favor of high tech fighters and believed that the F-16 could carry on the mission. After a series of tests with the F-16 (in one case renamed the A-16), the A-10 remained in service. More recently, some senior staff again wanted to push out the A-10 in favor of the F-35, but so far the A-10 has been slated for additional service life updates for the foreseeable future.