Fort Worth TX (SPX) May 28, 2008 – The United States Department of Defense has authorized the release of funds to buy six conventional takeoff and landing (CTOL) F-35A Lightning IIs for the U.S. Air Force, with provisional approval to purchase six short takeoff/vertical landing (STOVL) F-35Bs for the U.S. Marine Corps following a senior leadership review and the inaugural flight of that variant.