Lurch1o Posted July 6, 2024 Posted July 6, 2024 (edited) Happening all the time transiting the Black Sea or Northern Turkey. Also starting to get it in the Baltic and down over the Eastern Mediterranean. It can be a bit of a pain, as soon as you lose ADS B L or R then it’s time to check the GPS signal and switch over to DME/DME nav. The issue is that if the GPS dumps all satellites due to incorrect time coding then, due to the speed of the aircraft, it can take some time, or not at all, to get the ratified signals back. Hence there have been incidents, predominantly from Middle Eastern carriers, where aircraft are flying North Atlantic with compromised GPS systems. The problem here being that you are solely relying on INS with associated drift (especially after several hours compromised flight) which leads to gross nav errors! The linked systems are also compromised, eg EGPWS and forward terrain mapping. Hence these are often switched off to prevent spurious warnings on approach as the GPS doesn’t know where it actually is! Fun times. Edited July 6, 2024 by Lurch1o Spellunk
Recommended Posts