Originally Posted by
barry lloyd
Fair comment Dave, but I have also seen wrong origin/destination information attached to a particular flight as well - maybe for the same reasons
That's exactly correct. As with the aircraft registration, the route origin and destination aren't transmitted either via Mode S/ADS-B. So the flight trackers maintain databases that attempt to tie up Flight IDs with the route flown.
As we know, flight numbers change over time, plus the flight trackers attempt to tie up not only scheduled flights, but also ad hoc flight numbers (maintenance, positioning flights, etc) which can vary from day to day. Add the extra complication of alphanumeric callsigns designed to avoid callsign confusion for ATC, and it's no surprise that wrong routes are shown from time to time.