Boeing Company Undifferentiated or Other Model
Flight Crew Air Transport Pilot (ATP); Flight Crew Multiengine; Flight Crew Instrument
Situational Awareness
Aircraft Equipment Problem Less Severe; Deviation / Discrepancy - Procedural Published Material / Policy; Inflight Event / Encounter Other / Unknown
General None Reported / Taken
Airspace Structure; Procedure; Environment - Non Weather Related
The purpose of this report is to record suspected GPS jamming along the borders of Iran while in Turkish and Iraqi airspace. It has occurred in the same location during the past week on a few flights as mentioned by other crew members. The suspected jamming lasted almost exactly 30 minutes while on the following route: EMBAG UM688 SOBIL. Even though there were no deviations; no issues with (ATC) or no permanent system loss; this route is very close to the border with Iran (within 10 miles at some points) and could pose a danger to an aircraft with a malfunctioning inertial reference system (IRS). After passing EMBAG; the EICAS alert 'TRANSPONDER R' appeared. The right transponder was active at the time so we selected the left transponder. We were still in Turkish airspace with positive radar contact. Within a few minutes or so; we noticed the aircraft was no longer receiving GPS inputs to the navigation system; however; the IRS's were functioning properly. There was not an EICAS alert; such as >GPS LEFT; >GPS RIGHT; or >GPS; to bring this to our attention. At [a different coordinate]; the EICAS alert 'TRANSPONDER L' appeared; we switched back to the right transponder. At no time did ATC report a loss of information from our transponder. We entered Iraqi airspace under positive radar contact; the EICAS alert 'TERR POS' displayed. The GPS inputs to the navigation returned and all systems were normal with no EICAS alerts upon recall. The company can look at new routing if this continues to occur.
Captain reported experiencing 30 minutes of GPS jamming while flying along the borders of Iran in Turkish and Iraqi airspace.