Narrative:

Flight was from ory-paris to ewr-newark, via north atlantic track 'F'. All of the north coordinates for track 'F' were 49.00 except the one just prior to yyt-torbay, and it was 48.00 north 50.00 west. When loading the INS on the ground in paris, 49.00 north and 50.00 west was entered as a waypoint instead of 48.00 north and 50.00 west. This error was not detected during xchk and readback of coordinates prior to departure. At this particular phase of the flight, my duties as a flight engineer require me to direct my attention on other items. Therefore, other than making certain that the proper 'present position' is correct, I am not involved in the loading and xchking of the flight plan into the INS. Flight was flown as programmed, and properly plotted on plotting chart. Error was not discovered until gander ATC questioned our position of 40.00N and 50.00W. This crew is very meticulous about plotting waypoints, and mid-points between waypoints. It is my belief that had their attention not been diverted because of an abnormality in the display of INS information at 49.00 north and 45.00 west, this error would have been detected an corrected when the pilot was entered on the chart. This plot was not made because attention was focused on why certain information was being displayed on INS.

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Original NASA ASRS Text

Title: FLC OF AN WDB ON N ATLANTIC TRACK GOT OFF TRACK DUE TO MISPROGRAMMING THE INS NAVIGATIONAL COMPUTER.

Narrative: FLT WAS FROM ORY-PARIS TO EWR-NEWARK, VIA N ATLANTIC TRACK 'F'. ALL OF THE N COORDINATES FOR TRACK 'F' WERE 49.00 EXCEPT THE ONE JUST PRIOR TO YYT-TORBAY, AND IT WAS 48.00 N 50.00 W. WHEN LOADING THE INS ON THE GND IN PARIS, 49.00 N AND 50.00 W WAS ENTERED AS A WAYPOINT INSTEAD OF 48.00 N AND 50.00 W. THIS ERROR WAS NOT DETECTED DURING XCHK AND READBACK OF COORDINATES PRIOR TO DEP. AT THIS PARTICULAR PHASE OF THE FLT, MY DUTIES AS A FE REQUIRE ME TO DIRECT MY ATTN ON OTHER ITEMS. THEREFORE, OTHER THAN MAKING CERTAIN THAT THE PROPER 'PRESENT POS' IS CORRECT, I AM NOT INVOLVED IN THE LOADING AND XCHKING OF THE FLT PLAN INTO THE INS. FLT WAS FLOWN AS PROGRAMMED, AND PROPERLY PLOTTED ON PLOTTING CHART. ERROR WAS NOT DISCOVERED UNTIL GANDER ATC QUESTIONED OUR POS OF 40.00N AND 50.00W. THIS CREW IS VERY METICULOUS ABOUT PLOTTING WAYPOINTS, AND MID-POINTS BTWN WAYPOINTS. IT IS MY BELIEF THAT HAD THEIR ATTN NOT BEEN DIVERTED BECAUSE OF AN ABNORMALITY IN THE DISPLAY OF INS INFO AT 49.00 N AND 45.00 W, THIS ERROR WOULD HAVE BEEN DETECTED AN CORRECTED WHEN THE PLT WAS ENTERED ON THE CHART. THIS PLOT WAS NOT MADE BECAUSE ATTN WAS FOCUSED ON WHY CERTAIN INFO WAS BEING DISPLAYED ON INS.

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.