Narrative:

We had just crossed the north atlantic wbound and received our domestic clearance. We were cleared NA190 across canada. Company procedures call for checking and verifying the route in our manuals once we receive our clearance. We did this, and all points checked along the legs page of the FMC. Later I had stepped to the back of the aircraft for a moment. Evidently, while I was gone, the acting first officer must have changed the route on legs page from yna-castr-yri to yna-yri. Whether we were cleared direct in between these 2 points or what was never found out and I and the captain failed to catch this as we went along. Around about that time, one of the flight attendants came to the cockpit and informed us that 2 oxygen masks had dropped down but not activated. By now the acting first officer was back on his break, so the captain and I were dealing with the oxygen problem. We looked up the problem in the operating manual and discussions with the flight attendant kept us occupied on that problem. Once things settled down some, I was watching the flight plan and noticed that castr was a waypoint in between yna and yri but didn't show as such on our FMC. I then put castr into the FMC to find out that it was virtually on a direct route between yna/yri. We passed 11 mi south or abeam castr. Toronto center never mentioned anything, so we assumed that maybe we were cleared direct between the 2 fixes sometime ago, or it was somehow removed from the route in the FMC! Our preoccupation with re-computing fuel, etc, for the oxygen problem, going to a lower altitude for operational requirements, and the fact that castr was once in the FMC, led us to believe everything was ok. I feel that, when we alternate seats in the augmented crew, it is very important to update the others on anything that took place, so in case any other distraction (ie: oxygen problem) arises, we are better prepared for the situation. The first officer was brand new in international operations, so that may have led to the non-briefing, etc, while others were gone.

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Original NASA ASRS Text

Title: TRACK DEV IN FOREIGN AIRSPACE.

Narrative: WE HAD JUST CROSSED THE NORTH ATLANTIC WBOUND AND RECEIVED OUR DOMESTIC CLRNC. WE WERE CLRED NA190 ACROSS CANADA. COMPANY PROCS CALL FOR CHKING AND VERIFYING THE RTE IN OUR MANUALS ONCE WE RECEIVE OUR CLRNC. WE DID THIS, AND ALL POINTS CHKED ALONG THE LEGS PAGE OF THE FMC. LATER I HAD STEPPED TO THE BACK OF THE ACFT FOR A MOMENT. EVIDENTLY, WHILE I WAS GONE, THE ACTING FO MUST HAVE CHANGED THE RTE ON LEGS PAGE FROM YNA-CASTR-YRI TO YNA-YRI. WHETHER WE WERE CLRED DIRECT IN BTWN THESE 2 POINTS OR WHAT WAS NEVER FOUND OUT AND I AND THE CAPT FAILED TO CATCH THIS AS WE WENT ALONG. AROUND ABOUT THAT TIME, ONE OF THE FLT ATTENDANTS CAME TO THE COCKPIT AND INFORMED US THAT 2 OXYGEN MASKS HAD DROPPED DOWN BUT NOT ACTIVATED. BY NOW THE ACTING FO WAS BACK ON HIS BREAK, SO THE CAPT AND I WERE DEALING WITH THE OXYGEN PROB. WE LOOKED UP THE PROB IN THE OPERATING MANUAL AND DISCUSSIONS WITH THE FLT ATTENDANT KEPT US OCCUPIED ON THAT PROB. ONCE THINGS SETTLED DOWN SOME, I WAS WATCHING THE FLT PLAN AND NOTICED THAT CASTR WAS A WAYPOINT IN BTWN YNA AND YRI BUT DIDN'T SHOW AS SUCH ON OUR FMC. I THEN PUT CASTR INTO THE FMC TO FIND OUT THAT IT WAS VIRTUALLY ON A DIRECT RTE BTWN YNA/YRI. WE PASSED 11 MI S OR ABEAM CASTR. TORONTO CTR NEVER MENTIONED ANYTHING, SO WE ASSUMED THAT MAYBE WE WERE CLRED DIRECT BTWN THE 2 FIXES SOMETIME AGO, OR IT WAS SOMEHOW REMOVED FROM THE RTE IN THE FMC! OUR PREOCCUPATION WITH RE-COMPUTING FUEL, ETC, FOR THE OXYGEN PROB, GOING TO A LOWER ALT FOR OPERATIONAL REQUIREMENTS, AND THE FACT THAT CASTR WAS ONCE IN THE FMC, LED US TO BELIEVE EVERYTHING WAS OK. I FEEL THAT, WHEN WE ALTERNATE SEATS IN THE AUGMENTED CREW, IT IS VERY IMPORTANT TO UPDATE THE OTHERS ON ANYTHING THAT TOOK PLACE, SO IN CASE ANY OTHER DISTR (IE: OXYGEN PROB) ARISES, WE ARE BETTER PREPARED FOR THE SIT. THE FO WAS BRAND NEW IN INTL OPS, SO THAT MAY HAVE LED TO THE NON-BRIEFING, ETC, WHILE OTHERS WERE GONE.

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.