This happened to me three times in this version, before and after the hotfix.
Basically the aircraft is displayed as 0% health although NOT having been destroyed (status says airborne).
It shows in the base hangar but cannot be used for interception nor be relocated. It can be decommissioned.
I'm not sure how to reproduce this. I've been doing interceptions with single aircrafts and squadrons, auto resolving every time and using air strikes to clean crash sites.
The last time it happened to me the aircraft was in a 2 fighters squadron and won the fight with minor damage.
Attached are the 3 save games that show the bug.
unusable marauder 1.sav
unusable fox.sav
unusable marauder 2.sav
unusable marauder 1.sav
unusable fox.sav
unusable marauder 2.sav