Unlock the XFA-27 Fighter
Beat the game on normal. Play the game again on hard and make your way to the ''Dead-End'' mission. Destroy the four YF-23A's in the special Fox Force Four squadron south of the target to unlock the XFA-27 and a medal at the Debriefing screen.

Normal通关, 然后二周目Extra模式到 Mission Dead End, 在任务目标南部击落4架Fox Force Four squadron的YF-23A, 就有XFA-27了