Originally Posted by
ATC Watcher
interesting question , I did not hear that one before , I will add another if I may : on the Boeing 787 avionics are synchronized by the GPS clock signal , and once /jammed/spoofed you cannot reset the clock in flight and you lose many functions including CPDLC for the rest of the flight . Is it the same on the Airbus fleet ?
On the Airbus, SOP was to switch the clock to INT (internal) mode before entering a GPS interference area. CPDLC should still work up to 24hrs after this action as the clock remains accurate enough.
I’m on the 777 now and I’ve experienced clock spoofing. It was quite subtle (just a few minutes) and I only picked it up when filing out the nav log. Fortunately, the clock reset to the correct time when out of the interference area. We were not using CPDLC at the time.