Board Thread:Ace Combat 7/@comment-43842196-20190924015446/@comment-25045164-20190924022531

A possibility is that it didn't age well. Funny you mentioned X-02. While it boasted supreme maneuverability, it's prone to mechanical failure due to its moving parts. So, Erusea hired Grunder Industries to solve the plane's issues. This resulted in the making of X-02S. From here, it's possible that XFA-27 suffered similar problems but met a different fate, one that ensured it wouldn't see the light of day.