A320
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Flight Crew Last 90 Days 126; Flight Crew Type 1870
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types; Inflight Event / Encounter Other / Unknown
Air Traffic Control Issued New Clearance; Flight Crew Became Reoriented
Aircraft; Procedure; Environment - Non Weather Related; Airspace Structure
Halfway through flight at night; our first indication of a problem was aircraft went into 'uncommanded' 30-degree bank turn. Shortly thereafter; the ECAM message for 'NAV GPS1 FAULT' appeared. Then 'GPS PRIMARY LOST' in scratchpad. Later we got the ECAM 'NAV ADS-B REPORTING 1/2 FAULT.' There was a fair amount of confusion in the cockpit as the Captain ND showed right of course and correcting back to course while the First Officer ND showed left of course and diverging away from course. About the same time; ATC called and ask where we were navigating to. I reported 'position doubtful' and informed ATC we were having navigation difficulties. ATC gave us a vector. At the same time; multiple aircraft on the frequency reported having similar issues. ATC noted that military was doing a large drill to our south and that may be affecting GPS capability. I contacted Dispatch via phone patch. Dispatch did some investigation and found there was a large military operation in progress and NOTAM for possible GPS interference in our area. To say that my raw data navigation skills were lacking is an understatement! I've never done it on the Airbus and can't remember having done it in 25 years or more. All told; we were without GPS navigation for over 45 minutes. Why the aircraft did not go to radio updating for position in a reliable manner is unknown. We eventually landed uneventfully with all GPS capability restored. Aircraft maintenance write-ups completed.
Airbus Captain reported experiencing an uncommanded heading change and navigation display disruption due to GPS signal interference.