sry but i'm bad this ,.. what do you mean by using this flag .. and can you pls add it here 

 "flags": "AuthorizedDamage, HumanNPCDamage, LockedBoxesImmortal,ProtectedSleepers,LockedDoorsImmortal",

"flags": "AuthorizedDamage, HumanNPCDamage, LockedBoxesImmortal, ProtectedSleepers, LockedDoorsImmortal, MiniCopterIsImmuneToCollision"​

Perfect . Thank you . 

i was confuesd cuz its not in the flags list in the Documentation .. maybe you need to add it XD .