Commercial Fixed Wing
Flight Crew Air Transport Pilot (ATP); Flight Crew Instrument; Flight Crew Multiengine
Distraction; Human-Machine Interface; Workload
ATC Issue All Types; Aircraft Equipment Problem Less Severe
Flight Crew Overcame Equipment Problem
Aircraft; ATC Equipment / Nav Facility / Buildings; Environment - Non Weather Related; Software and Automation; Human Factors
Initially received ADS-B OUT L alert. Completed checklist by switching to a different transponder after approximately 10 minutes followed with ADS-B OUT R.  Subsequently noticed inertial mode. Indicative of GPS jamming. We were in Ukrainian airspace approaching the Crimean area at the time. Jamming indications continued intermittently for roughly 45 minutes until clear of the area. Current Russian military activity in the area suggests intentional GPS interference. Inform other crews that GPS jamming is occurring; if possible route flights further east to avoid activity area.
An air carrier pilot reported GPS jamming.