User blog comment:Generale wareagle/How to unlock the X-49, Ui-4045 and XF-900 on the japan version of Ace Combat 3/@comment-5947062-20130208141722/@comment-4535398-20130208163201

Well for the export version you had to do that while going through the story to unlock the planes, not the simulator. Also, this had to be done on Normal or Hard.