Let me just go ahead and tell you everything I have learned from hours of trying to repair/fly the 3 types of helicopters in this mod (might vary per server). First off the MH6 can have everything repaired except for the hull itself which leads to leaking fuel, making it non flyable. Mi8 does not have a script for being repaired but depending on it's state when it spawns you might get one flight out of it without a tail rotor or something. and lastly the only helicopter I have been able to get completely working is the UH-1 Huey, (which we lost due to a server restart after it saving while it was on the ground). Also vehicles do not re spawn in this mod and the only way to get more into your server is for a developer to manually place them so don't get your hopes up.