A navigational error (INS) was discovered en route, and resulted in air carrier's return.

Attributes
ACN	303024
Time
Date	199504
Day	Sat
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : tje
State Reference	FO
Altitude	msl bound lower : 35000 msl bound upper : 35000
Environment
Flight Conditions	IMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : rjtg
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude cruise other
Route In Use	enroute : pacific enroute : other oceanic enroute airway : rjtg enroute other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : flight engineer pilot : commercial pilot : cfi pilot : atp
Experience	flight time last 90 days : 180 flight time total : 12000 flight time type : 900
ASRS Report	303024
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	non adherence : published procedure non adherence : clearance other anomaly other
Independent Detector	other controllera other flight crewa
Resolutory Action	none taken : unable other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

Navigational error caused by improper loading of 'present position' in litton 92 INS. Present position was loaded by first officer and verified by captain but not by so as required by company policy. So was not available during check due to maintenance problem. 'Present position' in INS is not a checklist item. Error initially noted during climb out when VOR and INS position did not agree. This was confirmed several mi later when tokyo control advised we were 15 mi right of course. Due to complete dependence on INS for navigation to destination, flight was terminated and returned to fukuoka. INS error's noted on gate was 6.2 mi. There are 2 items that cannot be changed after takeoff: one is on-board fuel and the other is INS 'present position.' considering its importance, 'present position on INS should be a checklist item. Had the so checked, it is possible he would have noted the mistake.

Original NASA ASRS Text

Title: A NAVIGATIONAL ERROR (INS) WAS DISCOVERED ENRTE, AND RESULTED IN ACR'S RETURN.

Narrative: NAVIGATIONAL ERROR CAUSED BY IMPROPER LOADING OF 'PRESENT POS' IN LITTON 92 INS. PRESENT POS WAS LOADED BY FO AND VERIFIED BY CAPT BUT NOT BY SO AS REQUIRED BY COMPANY POLICY. SO WAS NOT AVAILABLE DURING CHK DUE TO MAINT PROB. 'PRESENT POS' IN INS IS NOT A CHKLIST ITEM. ERROR INITIALLY NOTED DURING CLBOUT WHEN VOR AND INS POS DID NOT AGREE. THIS WAS CONFIRMED SEVERAL MI LATER WHEN TOKYO CTL ADVISED WE WERE 15 MI R OF COURSE. DUE TO COMPLETE DEPENDENCE ON INS FOR NAV TO DEST, FLT WAS TERMINATED AND RETURNED TO FUKUOKA. INS ERROR'S NOTED ON GATE WAS 6.2 MI. THERE ARE 2 ITEMS THAT CANNOT BE CHANGED AFTER TKOF: ONE IS ON-BOARD FUEL AND THE OTHER IS INS 'PRESENT POS.' CONSIDERING ITS IMPORTANCE, 'PRESENT POS ON INS SHOULD BE A CHKLIST ITEM. HAD THE SO CHKED, IT IS POSSIBLE HE WOULD HAVE NOTED THE MISTAKE.

Data retrieved from NASA's ASRS site as of July 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.