Ok i know this posts are very very old but they are the first link if u google the problem with the autopilot:
Pls dont delte ur configs or smth like this just check this:
Options>Misc>UH-1H>Autopilot Availability:: deactivate and reactivate it restart the game and now it should work.
Sry for my english cya.
source:
http://steamcommunity.com/app/223750/discussions/0/616188677679383729/