If the Air Force succeeds in replacing the A-10 with the F-35, the Army needs to start training its own fixed wing pilots again and procure their own replacement for the A-10. The F-35 simply is not as mission capable for the close air support role:
http://defensetech.org/2015/01/02/a-tale-of-two-gatling-guns-f-35-vs-a-10/
“The GAU-22/A is lighter and more accurate than its predecessor, but with a reduced rate of fire of 3,300 rounds per minute. At that rate, the F-35 would be out of ammunition in about four seconds, or one or two bursts of fire.
By comparison, the 30mm, seven-barrel GAU-8/A Avenger in the nose of the venerable Warthog attack aircraft can hold as many as 1,174 rounds. It’s configured to fire at a fixed rate of fire of 3,900 rounds per minute.”