The analog collective axis is bugged the same way than in ArmA 2 with Saitek X52 Pro joystick. It acts weirdly, doesn't make sense when compared to raw input from the joystick throttle.
Regular collective axis is bugged too, with 0% raw input from throttle the collective in game is about 25%, rendering landings very difficult because the choppers are almost hovering (maintaining the contact with ground eg. in hills is very hard because of that), and with 100% raw input from throttle the collective in game is about 75%.