A B737-400 WAS DISPATCHED IN NON COMPLIANCE WITH AN AFT BOOST PUMP INOP AND DEFERRED; BUT FUEL ADDED PER THE MEL WAS NOT IDENTED AS UNUSABLE FUEL.

Narrative

JUN/XA/00; FLT XX; ZZZ-ANC; ACFT XYZ. PRIOR TO PUSHBACK AT ZZZ; RECEIVED RADIO CALL FROM FLC INDICATING AFT FUEL BOOST PUMP WAS INOP; AND THAT A MECH WAS ON BOARD. SINCE DISPATCH HAD NOT RECEIVED NOTIFICATION OF ANY SUCH MEL FROM MAINT CTL AS YET; I ASKED CREW WHAT MEL REF NUMBER WAS BEING CONTEMPLATED; AND WAS ADVISED BY CREW '28-1A;' AND WORDS TO THE EFFECT 'LOOKS LIKE WE CAN GO WITH THIS IF YOU CONCUR.' I THEN LOOKED UP 28-1A IN THE -400 MEL MANUAL AND SAW 1) BOTH MAIN TANK FORWARD PUMPS MUST BE OPERATING NORMALLY -- THEY WERE; 2) AT START OF TKOF ROLL; FUEL QUANTITY IN ASSOCIATED TANK MUST BE 7500 LBS OR MORE -- THERE WAS; 3) A MINIMUM FUEL QUANTITY OF 2500 LBS IS MAINTAINED IN THE ASSOCIATED TANK. SINCE THERE CAN BE NO PLANNED FUEL IMBAL; THIS LAST ITEM MEANT 2500 LBS OF FUEL MUST ALSO BE MAINTAINED IN THE OPPOSITE TANK FOR A TOTAL OF 5000 LBS. IN MY FUEL PLANNING FOR THIS FLT; I HAD ADDED 1000 LBS FOR POSSIBLE OVERBURN; AND EVEN THOUGH WX WAS GOOD AND FORECAST GOOD; I HAD 2 ALTERNATES FOR ANC LISTED (ENA AND EDF); SO IF FUEL WAS TO BECOME AN ISSUE; I COULD 'CUT BACK' TO THE CLOSER ALTERNATE (EDF). I ASKED CREW ON RADIO THEIR PRESENT FUEL LOAD; AND FOUND THE ACTUAL FUEL ON BOARD WAS 900 LBS OVER THE MINIMUM FUEL ON THE DISPATCH RELEASE. WITH THE 'EXTRA' FUEL OUTLINED ABOVE; PLUS NORMAL COMPANY FUEL RESERVES; THERE WAS NO QUESTION THE FLT WOULD ARRIVE ANC WITH MORE FUEL THAN WAS REQUIRED BY ITEM #3. THE MEL WAS ADDED BY MAINT CTL; AND THE FLT WAS DISPATCHED; AND THE FLT COMPLETED WITHOUT INCIDENT. THE NEXT MORNING (ACTUALLY; LATER THAT SAME MORNING) A SENIOR DISPATCHER WAS REVIEWING THE NEXT FLT SEGMENT FOR THIS ACFT; AND POINTED OUT THAT I SHOULD HAVE CONSIDERED THE 5000 LBS AS UNUSABLE FUEL; EVEN THOUGH THE MEL DOES NOT SAY THAT. IT SHOULD BE NOTED THAT THE MEL HAD BEEN REVISED ABOUT 2 DAYS EARLIER; AND THAT THE VERBIAGE WAS DIFFERENT THAN THE OLD VERSION -- AND MUCH LESS CLR IN MY OPINION.