Narrative:

This was a 2 pilot aircraft with augmented crew for over 12 hours of flight. I was one of the extra first officer's and at the time of occurrence I was technically off duty. The captain vacated his seat to take care of physiological needs and I climbed into his seat so the other first officer would not have to put on the oxygen mask. At this time we shortly crossed over the oed VOR northbound and aircraft headed directly for fings intersection as the area navigation FMC was programmed. About 50 NM north of oed, ZSE advised us we were left of track and asked us to verify we were on J-501. We indicated we were direct fings intersection and ATC advised us the direct route would take us across restr military airspace and on our request gave us a 15 degree right turn back to join J-501. As far as we know there was no traffic conflict. Up to this point I had not rechked the master flight plan which the other first officer was in charge of because the captain was flying this leg. Obviously I should have as soon as I climbed into the captain's seat to verify our routing. The flight plan did show J-501 to fings intersection not direct. The other first officer who had checked the master flight plan against the route said that he had only checked the FMC route after the oceanic gateway and had not checked the domestic portion and 95 percent of our trips go directly to the oceanic route without a long domestic portion. He also had not started the usual waypoint checking en route yet because we were in radar contact on a domestic route. He agreed that both of those omissions were an oversight he would not repeat.

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Original NASA ASRS Text

Title: ACR FLC DEVIATED FROM RTE CLRNC WHILE CAPT WAS ABSENT FROM DUTY STATION.

Narrative: THIS WAS A 2 PLT ACFT WITH AUGMENTED CREW FOR OVER 12 HRS OF FLT. I WAS ONE OF THE EXTRA FO'S AND AT THE TIME OF OCCURRENCE I WAS TECHNICALLY OFF DUTY. THE CAPT VACATED HIS SEAT TO TAKE CARE OF PHYSIOLOGICAL NEEDS AND I CLBED INTO HIS SEAT SO THE OTHER FO WOULD NOT HAVE TO PUT ON THE OXYGEN MASK. AT THIS TIME WE SHORTLY CROSSED OVER THE OED VOR NBOUND AND ACFT HEADED DIRECTLY FOR FINGS INTXN AS THE AREA NAV FMC WAS PROGRAMMED. ABOUT 50 NM N OF OED, ZSE ADVISED US WE WERE L OF TRACK AND ASKED US TO VERIFY WE WERE ON J-501. WE INDICATED WE WERE DIRECT FINGS INTXN AND ATC ADVISED US THE DIRECT RTE WOULD TAKE US ACROSS RESTR MIL AIRSPACE AND ON OUR REQUEST GAVE US A 15 DEG R TURN BACK TO JOIN J-501. AS FAR AS WE KNOW THERE WAS NO TFC CONFLICT. UP TO THIS POINT I HAD NOT RECHKED THE MASTER FLT PLAN WHICH THE OTHER FO WAS IN CHARGE OF BECAUSE THE CAPT WAS FLYING THIS LEG. OBVIOUSLY I SHOULD HAVE AS SOON AS I CLBED INTO THE CAPT'S SEAT TO VERIFY OUR ROUTING. THE FLT PLAN DID SHOW J-501 TO FINGS INTXN NOT DIRECT. THE OTHER FO WHO HAD CHKED THE MASTER FLT PLAN AGAINST THE RTE SAID THAT HE HAD ONLY CHKED THE FMC RTE AFTER THE OCEANIC GATEWAY AND HAD NOT CHKED THE DOMESTIC PORTION AND 95 PERCENT OF OUR TRIPS GO DIRECTLY TO THE OCEANIC RTE WITHOUT A LONG DOMESTIC PORTION. HE ALSO HAD NOT STARTED THE USUAL WAYPOINT CHKING ENRTE YET BECAUSE WE WERE IN RADAR CONTACT ON A DOMESTIC RTE. HE AGREED THAT BOTH OF THOSE OMISSIONS WERE AN OVERSIGHT HE WOULD NOT REPEAT.

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.