B777-200
Flight Crew Multiengine; Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument
Workload; Situational Awareness; Human-Machine Interface; Distraction; Confusion
Aircraft Equipment Problem Less Severe; Deviation - Track / Heading All Types
Flight Crew Overrode Automation; Flight Crew Overcame Equipment Problem; Flight Crew Became Reoriented
Software and Automation; Procedure; ATC Equipment / Nav Facility / Buildings
Suspected GPS jamming between LOGMU and ROKUB on T561 XA:17Z-XB:03Z. EICAS alert for NAV UNABLE RNP. Followed checklist and used radio/IRS updating during the event. Was able to resume normal GPS ops for remainder of flight. Most likely some crazy militants in the area. Perhaps pay the big bucks and fly over Siberia on this route. Most likely less GPS jamming and probably more efficient for flight planning. Although I appreciate the longer rest opportunities on these double crewed flights.
An air carrier Captain reported GPS jamming.