The FAA has issued Version 1.1 of its GNSS Interference Resource Guide, released in March, around three months after the first edition in December 2025. It was developed with input from the Performance Based Operations Rulemaking Committee's GPS/GNSS Disruption Action Team, of which the NBAA is a member. For protective teams that move principals by air through or near contested airspace, this is the working reference for how satellite-navigation interference behaves and what to do about it.
Jamming versus spoofing. The guide draws the distinction cleanly. Jamming is emissions that interfere with a receiver's ability to acquire and track GNSS signals — it denies navigation. Spoofing is emissions of GNSS-like signals that a receiver may track in combination with or instead of the real ones — it deceives, and is the more dangerous of the two because the system can fail confidently rather than visibly.
The practical drill. The guide sets out recognition signs — time shifts, position disagreements, moving-map anomalies, false terrain warnings — and the systems that degrade, including RNAV/RNP capability, ADS-B, datalink, synthetic vision and terrain awareness. The crew actions are to cross-check against non-GNSS sources, favour ground-based approaches after a suspected event, report to ATC in real time, and file a written anomaly report after landing. It also flags the human-factors load: higher workload, fatigue and mistrust of flight-deck systems.
The operator implication. Interference is now a planning factor across a long list of regions — the eastern Mediterranean, the Black Sea, the Baltic, the India-Pakistan border, Iraq and Iran among them. For air movement, that means three things: brief the crew on GNSS-degraded contingencies before departure, confirm the avionics behaviour your aircraft will exhibit under interference, and build route options that do not assume satellite navigation will hold. This is no longer an exotic risk confined to conflict zones; it is a standard line in the air-movement plan.
