The AH-6M (Little-Bird) in [[ https://steamcommunity.com/sharedfiles/filedetails/?id=843577117&searchtext=rhs | RHSUSAF ]] was able to take a fair beating prior to the v2.18 update.
Since the update hit, something was affected on it drastically and it can only take 3-5 5.56 rounds before being completely disabled at this point.
[[ https://www.youtube.com/watch?v=17_Ru9ulyYc | Video Example ]] - Recorded by a friend, but I've tested myself any it is just as bad, can be worse than shown here.
No other vehicles in the RHS Mod(s) were seemingly affected in the same way oddly.