Narrative:

Approximately 15 mins after returning from mine and the relief pilot's second break; we received a call from vancouver center asking if we were proceeding direct to yvr. When I had sat down in the seat being the second one up to the cockpit; I had heard the tail end of the changeover brief. For some reason I thought we were going direct to a point further past yvr so at that point it didn't look odd that yvr was off to the right. As soon as center called; we realized that LNAV was not engaged and we were on a heading. We replied to center that we were left of course and he then gave us direct to gtf. No conflict was created and center made no other mention of it. He did not ask why; or any other query. The rest of the flight was uneventful. After the captain and first officer returned; we asked them about it and we realized that they had been given direct to yvr just before their break started and the changeover occurred. They initially started towards yvr with heading select and LNAV was never engaged. We should have caught it during the brief and changeover. From now on; the first thing I will do besides getting a good brief is check that LNAV is engaged. Supplemental information from acn 802944: as we approached ornai; vancouver gave us the clearance: 'after ornai; you are cleared direct vancouver.' the captain stated that he wanted to include a couple of points between ornai and yvr so he said he would delay putting the direct into the FMC until ornai so he could use the abeam point function and have abeam points in the FMC. The problem happened when we got to ornai. The PF kicked it out of LNAV so as to use heading select to make the turn. Right at this moment; the time to switch out with the 2 relief pilots; I got up then and let the #2 relief pilot take his seat. He said vancouver had asked them if they were going direct to yvr a while after we had left the cockpit because they were well left of course. At this point; they discovered the aircraft was still in heading mode -- LNAV was never re-engaged.

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Original NASA ASRS Text

Title: B777 FLT CREW EXPERIENCED TRACK DEVIATION; CREW DISCOVERS ACFT IN HDG MODE RATHER THAN LNAV. THE SITUATION WAS COMPOUNDED BY VARIOUS CREW CHANGES AT THE TIME THEIR CLEARANCE WAS RECEIVED.

Narrative: APPROX 15 MINS AFTER RETURNING FROM MINE AND THE RELIEF PLT'S SECOND BREAK; WE RECEIVED A CALL FROM VANCOUVER CTR ASKING IF WE WERE PROCEEDING DIRECT TO YVR. WHEN I HAD SAT DOWN IN THE SEAT BEING THE SECOND ONE UP TO THE COCKPIT; I HAD HEARD THE TAIL END OF THE CHANGEOVER BRIEF. FOR SOME REASON I THOUGHT WE WERE GOING DIRECT TO A POINT FURTHER PAST YVR SO AT THAT POINT IT DIDN'T LOOK ODD THAT YVR WAS OFF TO THE R. AS SOON AS CTR CALLED; WE REALIZED THAT LNAV WAS NOT ENGAGED AND WE WERE ON A HDG. WE REPLIED TO CTR THAT WE WERE L OF COURSE AND HE THEN GAVE US DIRECT TO GTF. NO CONFLICT WAS CREATED AND CTR MADE NO OTHER MENTION OF IT. HE DID NOT ASK WHY; OR ANY OTHER QUERY. THE REST OF THE FLT WAS UNEVENTFUL. AFTER THE CAPT AND FO RETURNED; WE ASKED THEM ABOUT IT AND WE REALIZED THAT THEY HAD BEEN GIVEN DIRECT TO YVR JUST BEFORE THEIR BREAK STARTED AND THE CHANGEOVER OCCURRED. THEY INITIALLY STARTED TOWARDS YVR WITH HDG SELECT AND LNAV WAS NEVER ENGAGED. WE SHOULD HAVE CAUGHT IT DURING THE BRIEF AND CHANGEOVER. FROM NOW ON; THE FIRST THING I WILL DO BESIDES GETTING A GOOD BRIEF IS CHK THAT LNAV IS ENGAGED. SUPPLEMENTAL INFO FROM ACN 802944: AS WE APCHED ORNAI; VANCOUVER GAVE US THE CLRNC: 'AFTER ORNAI; YOU ARE CLRED DIRECT VANCOUVER.' THE CAPT STATED THAT HE WANTED TO INCLUDE A COUPLE OF POINTS BTWN ORNAI AND YVR SO HE SAID HE WOULD DELAY PUTTING THE DIRECT INTO THE FMC UNTIL ORNAI SO HE COULD USE THE ABEAM POINT FUNCTION AND HAVE ABEAM POINTS IN THE FMC. THE PROB HAPPENED WHEN WE GOT TO ORNAI. THE PF KICKED IT OUT OF LNAV SO AS TO USE HDG SELECT TO MAKE THE TURN. RIGHT AT THIS MOMENT; THE TIME TO SWITCH OUT WITH THE 2 RELIEF PLTS; I GOT UP THEN AND LET THE #2 RELIEF PLT TAKE HIS SEAT. HE SAID VANCOUVER HAD ASKED THEM IF THEY WERE GOING DIRECT TO YVR A WHILE AFTER WE HAD LEFT THE COCKPIT BECAUSE THEY WERE WELL L OF COURSE. AT THIS POINT; THEY DISCOVERED THE ACFT WAS STILL IN HDG MODE -- LNAV WAS NEVER RE-ENGAGED.

Data retrieved from NASA's ASRS site as of May 2009 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.