Narrative:

First officer loaded 49N 50W instead of 48N 50W in all 3 INS units using remote loading with #2 as master while at the gate at ory (paris orly). We checked the waypoints with my reading the coordinates from the #1 INS with the first officer confirming each one. He failed to note the error. After crossing 40W the first officer noted that the #2 INS which was in triple mix and coupled to the #2 autoplt had a flashing 'east' where it normally has a 'U' when in triple mix. The east and U would alternate appearing on the #2 unit. We spent considerable time trying to determine what this meant and how it was affecting our track. This is the time that I normally plot our position. I somehow mentally substituted checking the INS units for the plotting I always do without fail. Then about the time the unit (#2 INS) started operating normally we encountered moderate turbulence. I made 3 radio reports to other aircraft about the turbulence. Gander control told us we had passed over 49N 50W instead of 48N 50W. There had been no conflict with traffic, but since we were 60 mi north of course and on the wrong nat track the potential was all too clear. I allowed a distraction to affect my normal procedures, and it was at a critical time. I'm fully aware that mistakes are made, but that procedures, if followed, will catch most of them.

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Original NASA ASRS Text

Title: FO OF AN WDB MISSED PROGRAMMED A FIX IN THE INS NAV UNITS CAUSING AN OFF COURSE N ATLANTIC TRACK OF 60 MI.

Narrative: FO LOADED 49N 50W INSTEAD OF 48N 50W IN ALL 3 INS UNITS USING REMOTE LOADING WITH #2 AS MASTER WHILE AT THE GATE AT ORY (PARIS ORLY). WE CHKED THE WAYPOINTS WITH MY READING THE COORDINATES FROM THE #1 INS WITH THE FO CONFIRMING EACH ONE. HE FAILED TO NOTE THE ERROR. AFTER XING 40W THE FO NOTED THAT THE #2 INS WHICH WAS IN TRIPLE MIX AND COUPLED TO THE #2 AUTOPLT HAD A FLASHING 'E' WHERE IT NORMALLY HAS A 'U' WHEN IN TRIPLE MIX. THE E AND U WOULD ALTERNATE APPEARING ON THE #2 UNIT. WE SPENT CONSIDERABLE TIME TRYING TO DETERMINE WHAT THIS MEANT AND HOW IT WAS AFFECTING OUR TRACK. THIS IS THE TIME THAT I NORMALLY PLOT OUR POS. I SOMEHOW MENTALLY SUBSTITUTED CHKING THE INS UNITS FOR THE PLOTTING I ALWAYS DO WITHOUT FAIL. THEN ABOUT THE TIME THE UNIT (#2 INS) STARTED OPERATING NORMALLY WE ENCOUNTERED MODERATE TURB. I MADE 3 RADIO RPTS TO OTHER ACFT ABOUT THE TURB. GANDER CTL TOLD US WE HAD PASSED OVER 49N 50W INSTEAD OF 48N 50W. THERE HAD BEEN NO CONFLICT WITH TFC, BUT SINCE WE WERE 60 MI N OF COURSE AND ON THE WRONG NAT TRACK THE POTENTIAL WAS ALL TOO CLR. I ALLOWED A DISTR TO AFFECT MY NORMAL PROCS, AND IT WAS AT A CRITICAL TIME. I'M FULLY AWARE THAT MISTAKES ARE MADE, BUT THAT PROCS, IF FOLLOWED, WILL CATCH MOST OF THEM.

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.