Around where I'm flying this is sadly a daily occurrence, and the symptoms depend somewhat on how long you are in an area of GPS interference. It begins usually with a scratchpad message GPS INVALID L / R, and UTC time being removed from the onside clocks. The ANP will increase somewhat of course, depending on the other enabled update sources. In maybe 5 percent of the cases the spoofing was so successful as to actually show an incorrect time and date on the clocks (and therefore also affect the FMS predictions). If this condition persists for a while, you may get a GPS and GLS light (initially on recall if only one sensor has given up). Around this time the RAAS INOP light illuminated and the TERR POS flag will show on the ND instead of the terrain display. I've had false EGPWS warnings twice in such conditions, once on final approach passing 500ft I received a TOO LOW - TERRAIN alert, and another day during rollout after landing a TERRAIN TERRAIN... Lovely stuff, throws you right back to the 90s with conventional navigation.
Last edited by STBYRUD; 7th January 2024 at 18:53.