Just over three months after releasing the first edition of its GPS/GNSS Interference Resource Guide in December, the FAA has issued an updated Version 1.1 with practical changes largely targeting pilot awareness.
The revised guide adds more detailed cockpit guidance on how to recognize interference, including expanded references to signs such as time shifts, position disagreements, moving-map anomalies, false terrain warnings and other indications that onboard systems may no longer be receiving reliable satellite data.
The update also gives crews a clearer picture of how a GNSS disruption can affect the flight deck beyond basic navigation. The FAA notes that interference can degrade or disable functions tied to position and timing data, including RNAV/RNP capability, ADS-B, CPDLC, automatic navaid tuning, synthetic vision, HUDs and TAWS.
It also notes that some spoofing effects can continue even after an aircraft leaves the affected area, which is why it emphasizes cross-checking against non-GNSS sources. Pilots should utilize independent time references and favor ground-based approaches when available after a suspected event.
The FAA also reminds pilots to report suspected jamming or spoofing to ATC as it happens and follow up with a written anomaly report after landing.