Narrative:

During climbout; I noticed a small amount of fuel in auxiliary tanks and center wing tank. I'm not sure if the fuel was in auxiliary tanks at the gate; but I don't remember seeing it when we ran the before start checklist. The amounts were 400 pounds in each auxiliary tank and 350 pounds in center tank. Overall fuel load was approximately 14;000 pounds at takeoff and gross weight was 127;470 per closeout. Climbing out of 10;000 ft I selected center fuel pumps on and auxiliary fuel pumps to auto to feed/transfer the small amount of fuel in those tanks. A couple of minutes later; we received a revised load closeout reducing our gross weight to 126;620 with no change in passenger; cargo; or zero fuel weight. A note at the bottom of revised closeout stated that '850 pounds of auxiliary fuel factored as part of eow; not fuel'. By this point we had already transferred auxiliary fuel and burned most of it. No mention of ballast fuel but fuel on board was reduced by 850 pounds. We may have violated procedure by burning the auxiliary fuel but I am honestly not sure. No safety implications; center of gravity only changed .2% and trim stayed the same. We may have taken off with a non-standard fuel load without the appropriate performance data to account for it.

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Original NASA ASRS Text

Title: A MD80 Captain burned the AUX and Center tank fuel during climb then received a revised weight and balance indicating that AUX and Center tank fuel was considered ballast.

Narrative: During climbout; I noticed a small amount of fuel in AUX tanks and Center wing tank. I'm not sure if the fuel was in AUX tanks at the gate; but I don't remember seeing it when we ran the Before Start checklist. The amounts were 400 LBS in each AUX tank and 350 LBS in Center tank. Overall fuel load was approximately 14;000 LBS at takeoff and gross weight was 127;470 per closeout. Climbing out of 10;000 FT I selected Center fuel pumps on and AUX fuel pumps to auto to feed/transfer the small amount of fuel in those tanks. A couple of minutes later; we received a revised load closeout reducing our gross weight to 126;620 with no change in passenger; cargo; or zero fuel weight. A note at the bottom of revised closeout stated that '850 LBS of AUX fuel factored as part of EOW; not fuel'. By this point we had already transferred AUX fuel and burned most of it. No mention of ballast fuel but fuel on board was reduced by 850 LBS. We may have violated procedure by burning the AUX fuel but I am honestly not sure. No safety implications; center of gravity only changed .2% and trim stayed the same. We may have taken off with a non-standard fuel load without the appropriate performance data to account for it.

Data retrieved from NASA's ASRS site as of April 2012 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.