Narrative:

En route from stl to slc -- planned fuel burn 17K -- 25K on board. Winds at altitude 265/115 -- after takeoff FMC said landing fuel would be 2.3. My immediate concern was accuracy of FMC information or where to go for fuel. While checking different cruise altitude and adding wind to see what optimum altitude should be the aircraft drifted off course. Course was from hallsville VOR to mke. I ended up south of course. After realizing position and correcting back, ZKC, who never realized the navigation error either, suddenly saw a conflict. A turn was commenced to avoid an airliner. TCASII never showed a target. In retrospect, I should have given the first officer the responsibility of flying, navigating, etc while I studied the computer. We both had our heads in and down. Unhealthy.

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Original NASA ASRS Text

Title: MLG DRIFTS OFF COURSE WHILE COMPUTING FUEL ACCURACY.

Narrative: ENRTE FROM STL TO SLC -- PLANNED FUEL BURN 17K -- 25K ON BOARD. WINDS AT ALT 265/115 -- AFTER TKOF FMC SAID LNDG FUEL WOULD BE 2.3. MY IMMEDIATE CONCERN WAS ACCURACY OF FMC INFO OR WHERE TO GO FOR FUEL. WHILE CHKING DIFFERENT CRUISE ALT AND ADDING WIND TO SEE WHAT OPTIMUM ALT SHOULD BE THE ACFT DRIFTED OFF COURSE. COURSE WAS FROM HALLSVILLE VOR TO MKE. I ENDED UP S OF COURSE. AFTER REALIZING POS AND CORRECTING BACK, ZKC, WHO NEVER REALIZED THE NAV ERROR EITHER, SUDDENLY SAW A CONFLICT. A TURN WAS COMMENCED TO AVOID AN AIRLINER. TCASII NEVER SHOWED A TARGET. IN RETROSPECT, I SHOULD HAVE GIVEN THE FO THE RESPONSIBILITY OF FLYING, NAVIGATING, ETC WHILE I STUDIED THE COMPUTER. WE BOTH HAD OUR HEADS IN AND DOWN. UNHEALTHY.

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.