'Had to abort major mission across north pole on B-52H 33 yrs ago 'cause heading system and radar scope presentation differed by 2 degrees from correct runway orientation when when we took runway. B-52H then had very good and accurate heading and bombing/navigation stabilization system, but when it went wrong, it could be VERY wrong. I would not start into high arctic with erroneous system. At least a cursory rolling heading check when Comair took runway may have saved 49 lives and more.
Wilton
