Narrative:

During cruise flight at FL360; relief pilot left the cockpit to tend to personal physiological needs. Upon returning to cockpit duties and donning headset; bahrain center issued an immediate right turn of 30 degrees; which was complied with. Bahrain center then queried as to why the aircraft was proceeding to bah (bahrain VOR). Relief pilot advised bahrain the flight was cleared: N929 nobla M600 bah A791 silno. Bahrain center advised aircraft was previously cleared to silno via N929. Pm asked PF if a reroute was issued whilst the pm was away from cockpit duties; to which he replied 'yes.' relief pilot was never advised upon returning to cockpit duties of the re-route clearance). Relief pilot asked PF to confirm the clearance received; to which he replied 'cleared direct to silno via N929;' direct silno; resulting in the gne (gross navigation error). Review of the middle east high 1/2 chart confirmed silno as the clearance limit via airway N929. Had the PF entered the flight plan page in the FMS and selected silno as the clearance limit via airway N929; the gne would not have occurred. FMS routing was corrected to reflect the clearance issued by bahrain center. Crew was active; though not on duty; during the period XA00-XM00. Mission tasking received after XM00 hours; and executed at XP00. Operations were conducted during a 'reverse cycle' period; affecting circadian cycle and cognitive skills. Incident occurred during the return leg to forward operating base in the very early morning hours; suggesting fatigue resulting in a lowered state of vigilance and situational awareness.operation is comprised of multi-national personnel. All personnel assigned possess an english language proficiency level of 4 or greater. Personnel assigned to conduct this mission were french (PF) and us (pm/AC [aircraft commander]); respectively; with us; U.K.; australia and bahrain personnel assigned to bahrain sector control. PF acknowledged the ATC clearance; in spite of not fully comprehending its contents. This resulted in failure to accurately execute clearance instructions; which resulted in a gne. In addition; PF failed to brief the relief pilot upon return to assigned cockpit duty station per SOP.

Google
 

Original NASA ASRS Text

Title: A military FA-50 suffered a gross navigation error in foreign airspace when; in the absence of the aircraft commander; the other pilot accepted a reroute; which was not completely understood and then programmed it incorrectly in the FMC and; finally; failed to brief the AC upon his return to the flight deck.

Narrative: During cruise flight at FL360; Relief Pilot left the cockpit to tend to personal physiological needs. Upon returning to cockpit duties and donning headset; Bahrain Center issued an immediate right turn of 30 degrees; which was complied with. Bahrain Center then queried as to why the aircraft was proceeding to BAH (Bahrain VOR). Relief Pilot advised Bahrain the flight was cleared: N929 NOBLA M600 BAH A791 SILNO. Bahrain Center advised aircraft was previously cleared to SILNO via N929. PM asked PF if a reroute was issued whilst the PM was away from cockpit duties; to which he replied 'YES.' Relief Pilot was never advised upon returning to cockpit duties of the re-route clearance). Relief Pilot asked PF to confirm the clearance received; to which he replied 'cleared direct to SILNO via N929;' direct SILNO; resulting in the GNE (Gross Navigation Error). Review of the Middle East High 1/2 chart confirmed SILNO as the clearance limit via airway N929. Had the PF entered the flight plan page in the FMS and selected SILNO as the clearance limit via airway N929; the GNE would not have occurred. FMS routing was corrected to reflect the clearance issued by Bahrain Center. Crew was active; though not on duty; during the period XA00-XM00. Mission tasking received after XM00 hours; and executed at XP00. Operations were conducted during a 'reverse cycle' period; affecting circadian cycle and cognitive skills. Incident occurred during the return leg to Forward Operating Base in the very early morning hours; suggesting fatigue resulting in a lowered state of vigilance and situational awareness.Operation is comprised of multi-national personnel. All personnel assigned possess an English Language Proficiency Level of 4 or greater. Personnel assigned to conduct this mission were French (PF) and U.S. (PM/AC [Aircraft Commander]); respectively; with U.S.; U.K.; Australia and Bahrain personnel assigned to Bahrain sector control. PF acknowledged the ATC clearance; in spite of not fully comprehending its contents. This resulted in failure to accurately execute clearance instructions; which resulted in a GNE. In addition; PF failed to brief the Relief Pilot upon return to assigned cockpit duty station per SOP.

Data retrieved from NASA's ASRS site as of April 2012 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.