Narrative:

On pushback to operate flight; right FMC fail EICAS message appeared. We spoke to mechanic on the headset and reset the right FMC circuit breakers with no fix. Called flight control and patched to maintenance control for deferral. We consulted MEL and saw that; referencing 34-61-XXX; it was not underlined and deferrable. As we referenced the operations procedures; we accomplished the first step in them of switching the first officer to the good FMC. Remainder of procedure was specific to left or right FMC failure. We flipped page over to review right FMC failure operations procedures to note proper VNAV/LNAV usage. We reviewed those and noted that there were no maintenance procedures or limitations in the 2 applicable columns next to the operations procedures for the right FMC failure. That is where our mistake happened. The maintenance procedures were on the previous page adjacent to the left FMC failure operations procedures. By not flipping the page back; I totally overlooked the necessary maintenance procedure including a required deferred maintenance procedure. Maintenance control called with our deferral number and it was not the MEL system number we expected. We had reviewed 34-61-XXX (single FMC failure non ETOPS operations). He gave us 34-61-xxy single FMC failure for ETOPS operations. I queried him and he said they wanted to keep the airplane available for ETOPS and so would use that deferral authority/authorized. I did not think to go back and review that different MEL section as I was thinking of operations procedures that we had read. This resulted in a second procedure I did not accomplish (verifying satellite navigation system was operative). In review; while we did not rush; if I had taken a little additional time to once again review the procedures applicable to the deferred system; I would have caught my major oversight. In the future; I will be most cognizant of the need to closely follow the flow of the text on the applicable pages and to triplechk that I am in the right place on the right page(south) to accomplish what needed to be done. We were fortunate that our oversight was not of a problem whose omission could have hurt us or caused damage.

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Original NASA ASRS Text

Title: A B767 FMC FAILED DURING PUSHBACK FOR DEP. TWO ERRORS WERE MADE WHILE THE MEL PROCEDURES WERE COMPLETED.

Narrative: ON PUSHBACK TO OPERATE FLT; R FMC FAIL EICAS MESSAGE APPEARED. WE SPOKE TO MECH ON THE HEADSET AND RESET THE R FMC CIRCUIT BREAKERS WITH NO FIX. CALLED FLT CTL AND PATCHED TO MAINT CTL FOR DEFERRAL. WE CONSULTED MEL AND SAW THAT; REFING 34-61-XXX; IT WAS NOT UNDERLINED AND DEFERRABLE. AS WE REFED THE OPS PROCS; WE ACCOMPLISHED THE FIRST STEP IN THEM OF SWITCHING THE FO TO THE GOOD FMC. REMAINDER OF PROC WAS SPECIFIC TO L OR R FMC FAILURE. WE FLIPPED PAGE OVER TO REVIEW R FMC FAILURE OPS PROCS TO NOTE PROPER VNAV/LNAV USAGE. WE REVIEWED THOSE AND NOTED THAT THERE WERE NO MAINT PROCS OR LIMITATIONS IN THE 2 APPLICABLE COLUMNS NEXT TO THE OPS PROCS FOR THE R FMC FAILURE. THAT IS WHERE OUR MISTAKE HAPPENED. THE MAINT PROCS WERE ON THE PREVIOUS PAGE ADJACENT TO THE L FMC FAILURE OPS PROCS. BY NOT FLIPPING THE PAGE BACK; I TOTALLY OVERLOOKED THE NECESSARY MAINT PROC INCLUDING A REQUIRED DEFERRED MAINT PROC. MAINT CTL CALLED WITH OUR DEFERRAL NUMBER AND IT WAS NOT THE MEL SYS NUMBER WE EXPECTED. WE HAD REVIEWED 34-61-XXX (SINGLE FMC FAILURE NON ETOPS OPS). HE GAVE US 34-61-XXY SINGLE FMC FAILURE FOR ETOPS OPS. I QUERIED HIM AND HE SAID THEY WANTED TO KEEP THE AIRPLANE AVAILABLE FOR ETOPS AND SO WOULD USE THAT DEFERRAL AUTH. I DID NOT THINK TO GO BACK AND REVIEW THAT DIFFERENT MEL SECTION AS I WAS THINKING OF OPS PROCS THAT WE HAD READ. THIS RESULTED IN A SECOND PROC I DID NOT ACCOMPLISH (VERIFYING SATELLITE NAV SYS WAS OPERATIVE). IN REVIEW; WHILE WE DID NOT RUSH; IF I HAD TAKEN A LITTLE ADDITIONAL TIME TO ONCE AGAIN REVIEW THE PROCS APPLICABLE TO THE DEFERRED SYS; I WOULD HAVE CAUGHT MY MAJOR OVERSIGHT. IN THE FUTURE; I WILL BE MOST COGNIZANT OF THE NEED TO CLOSELY FOLLOW THE FLOW OF THE TEXT ON THE APPLICABLE PAGES AND TO TRIPLECHK THAT I AM IN THE RIGHT PLACE ON THE RIGHT PAGE(S) TO ACCOMPLISH WHAT NEEDED TO BE DONE. WE WERE FORTUNATE THAT OUR OVERSIGHT WAS NOT OF A PROB WHOSE OMISSION COULD HAVE HURT US OR CAUSED DAMAGE.

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.