Delta Air Lines flew True Track up until about five years ago. I understand that they run in Mag these days and for what reason, I do not know? Track or Heading up is an option for the B777 customer to determine when they order the airplane from Boeing. I assume it is a pin selectable option and thus can chnged at will along with a Boeing Engineering authorization. I'm sure someone will chime in here but I think BA uses the Heading up in lieu of Track up. I fly the B777 sim quite often and it always pays to check just what config is playing that day in the sim. Personnaly I think all long-range nav should be conducted in True, but I learned sometime back, that my opinion does not count for much these days.
