Air carrier widebody transport deviated from clearance route. Track heading deviation.

Attributes
ACN	123339
Time
Date	198909
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : onc
State Reference	FO
Altitude	msl bound lower : 37000 msl bound upper : 37000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : rjtg tracon : abq
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 3 Turbojet Eng
Navigation In Use	Other
Flight Phase	cruise other
Route In Use	enroute : pacific enroute airway : g581 enroute other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Experience	flight time last 90 days : 120 flight time total : 16000 flight time type : 4200
ASRS Report	123339
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : commercial pilot : instrument pilot : cfi pilot : atp
Experience	flight time last 90 days : 160 flight time total : 26000 flight time type : 2000
ASRS Report	123198
Events
Anomaly	aircraft equipment problem : less severe non adherence : clearance other spatial deviation
Independent Detector	other controllera other flight crewa
Resolutory Action	flight crew : returned to intended course or assigned course other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Approximately 60-70 mi prior to reaching saban intersection, I left the cockpit. I returned to the cockpit 8-10 mins later and noticed the aircraft was approximately 20 mi right of course and on a heading of 180 degree (should have been heading 055 degree). The captain stated he didn't notice the aircraft unplanned turn due to involvement in making the position report and making the required flight plan entries. We immediately turned back on course! The INS had previously been written up (and problem corrected) as not accepting insertions correctly. I feel the captain did not notice the incorrect turn because of preoccupation with the flight plan, reporting, and the late hour. Supplemental information from acn 123198: the aircraft started to turn but I paid little attention as there was a course correction of about 10 degree. We had strayed about 4 mi off course. Naha control called and asked if we had a problem. We recrossed saban about 10 mins after the first passage.

Original NASA ASRS Text

Title: ACR WDB DEVIATED FROM CLRNC ROUTE. TRACK HEADING DEVIATION.

Narrative: APPROX 60-70 MI PRIOR TO REACHING SABAN INTXN, I LEFT THE COCKPIT. I RETURNED TO THE COCKPIT 8-10 MINS LATER AND NOTICED THE ACFT WAS APPROX 20 MI RIGHT OF COURSE AND ON A HDG OF 180 DEG (SHOULD HAVE BEEN HDG 055 DEG). THE CAPT STATED HE DIDN'T NOTICE THE ACFT UNPLANNED TURN DUE TO INVOLVEMENT IN MAKING THE POSITION REPORT AND MAKING THE REQUIRED FLT PLAN ENTRIES. WE IMMEDIATELY TURNED BACK ON COURSE! THE INS HAD PREVIOUSLY BEEN WRITTEN UP (AND PROBLEM CORRECTED) AS NOT ACCEPTING INSERTIONS CORRECTLY. I FEEL THE CAPT DID NOT NOTICE THE INCORRECT TURN BECAUSE OF PREOCCUPATION WITH THE FLT PLAN, REPORTING, AND THE LATE HOUR. SUPPLEMENTAL INFORMATION FROM ACN 123198: THE ACFT STARTED TO TURN BUT I PAID LITTLE ATTN AS THERE WAS A COURSE CORRECTION OF ABOUT 10 DEG. WE HAD STRAYED ABOUT 4 MI OFF COURSE. NAHA CTL CALLED AND ASKED IF WE HAD A PROBLEM. WE RECROSSED SABAN ABOUT 10 MINS AFTER THE FIRST PASSAGE.

Data retrieved from NASA's ASRS site as of August 2007 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.