Md-11 pilot crew reported possible GPS jamming.

Attributes
ACN	1715022
Time
Date	202001
Local Time Of Day	1201-1800
Place
Locale Reference	LTAA.ARTCC
State Reference	FO
Environment
Flight Conditions	VMC
Aircraft 1
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Flight Phase	Cruise
Route In Use	Direct
Flight Plan	IFR
Component
Aircraft Component	GPS & Other Satellite Navigation
Person 1
Function	Pilot Flying First Officer
Qualification	Flight Crew Multiengine Flight Crew Private Flight Crew Commercial Flight Crew Instrument
Person 2
Function	Pilot Not Flying Captain
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Clearance Deviation - Procedural Published Material / Policy Deviation - Track / Heading All Types

Narrative:

In cruise flight at FL340 northbound direct to ninva (fir boundary turkey). We received ATC transponder 1 & 2 alerts/ads B out fault; along with GNS sensor fail messages. We expected these to be associated with GPS jamming and complied QRH procedures. During the evaluation of these malfunctions and unannounced to us; the aircraft reverted into speed; heading and altitude hold (white annunciations). During this time the aircraft reached ninva and did not turn towards srt as it was not in navigation mode. We noticed the error and were also queried by ATC. Less than five miles off course; we corrected and were given direct srt. Flight continued to destination without further incident. GPS jamming caused prof/navigation issues. Better monitoring and awareness during GPS jamming and transponder issues.

Original NASA ASRS Text

Title: MD-11 pilot crew reported possible GPS jamming.

Narrative: In cruise flight at FL340 northbound direct to NINVA (FIR boundary Turkey). We received ATC transponder 1 & 2 alerts/ADS B out fault; along with GNS sensor fail messages. We expected these to be associated with GPS jamming and complied QRH procedures. During the evaluation of these malfunctions and unannounced to us; the aircraft reverted into speed; heading and altitude hold (white annunciations). During this time the aircraft reached NINVA and did not turn towards SRT as it was not in NAV mode. We noticed the error and were also queried by ATC. Less than five miles off course; we corrected and were given direct SRT. Flight continued to destination without further incident. GPS jamming caused PROF/NAV issues. Better monitoring and awareness during GPS jamming and transponder issues.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.