WICHITA, Kan. (AP) -- The U.S. Air Force is defending its decision to award a contract for a light air support plane to Sierra Nevada Corp. in the wake of a formal protest by Wichita-based Beechcraft.

Air Force spokesman Ed Gulick said in a statement this week the Air Force restarted the competition for the contract last May with a new evaluation team as well as internal and external advisers. He says the Air Force is confident that its decision is well supported and that the proposals were fairly evaluated.

The contract for 20 planes for use in Afghanistan is worth more than $427 million. It could much as $1 billion, depending on future orders.

Gulick says the Government Accountability Office has up to 100 days to make a decision on Beechcraft's protest.