I’ve added support for the Mission Enhanced Little Birds to my Head Range Plus addon. Subscribe and find out more here:
http://steamcommunity.com/sharedfiles/filedetails/?id=630737877
This addon will increase the range of head motion that is possible in first person view while in airplanes, helicopters, VTOLs, boats, ships, subs, tanks and cars when using TrackIR. This includes adding the ability to move your view left/right, up/down and front/back when inside a vehicle.