ACR MLG FLC DEV IN PERFORMING AN OVERWT TKOF.

Narrative

AS CAPT OF ACR FLT BTWN DET-STL; SHORTLY AFTER ARRIVING AT THE ACFT FOR THIS ORIGINATOR; I BECAME AWARE OF THE FACT THAT WE COULD BE OPERATING THIS FLT CLOSE TO THE RWY LIMIT WTS FOR RWY 15 AT DET. ABOUT 10 MINS PRIOR TO PUSH; I RECEIVED A CALL FROM THE DISPATCHER; REGARDING OUR WT; FUEL AND THE ST LOUIS WX. DISPATCH AND I READILY AGREED NOT TO CUT ANY FUEL FROM OUR LOAD OF 17400 POUNDS. THIS FUEL LOAD ALLOWED FOR A BUR OF 7400 POUNDS TO STL AND HOLDING FUEL OF ABOUT 30 MIN BEFORE PROCEEDING TO OUR ALTERNATE IF REQUIRED. THE WT LIMIT ON THE RELEASE WAS 100000 POUNDS. THE OPS AGENT INDICATED THAT THE ACTUAL WT WOULD BE UNDER THAT WT. AS THE FO AND I FINISHED UP OUR BEFORE START ORIGINATING CHKLIST; THE OPS AGENT HANDED US THE LOAD MANIFEST WITH AN ACFT WT OF 100900 POUNDS. AFTER CONSIDERING WHERE WE COULD CUT OUR WT; MY FO AND I DECIDED TO CALL DISPATCH AND RAISE OUR RELEASE WT. THIS WE ACCOMPLISHED BY ADDING TO THE BLEEDS OFF RWY LIMIT (RWY 15) WT OF 99700 POUNDS (AT 72 DEG F) A 425 POUND CORRECTION FOR HEADWIND (210 DEGS AT 11 KTS) AND A 500 POUND CORRECTION FOR PRESSURE ALT (ALTIMETER OF 30.10). I CALLED DISPATCH BACK; HE AGREED AND THE RELEASE COPIES WERE ANNOTATED WITH A NEW TKOF WT OF 100600 POUNDS. IN MY CARE TO CONSIDER ALL THE FACTORS AND IN MY HASTE TO GET THE FLT UNDERWAY; I NEGLECTED TO CONSIDER THE FACT THAT THE PUSH WT OF 100900 POUNDS ON OUR MANIFEST IS NOT A PUSH WT; IT'S A TKOF WT AS THE TAXI FUEL IS ALREADY SUBTRACTED. HENCE; WE ACTUALLY PUSHED THE GATE AT 101200 POUNDS AND TOOK OFF AT 100900 POUNDS. I DIDN'T REALIZE MY MISTAKE UNTIL DRIVING HOME LATER IN THE DAY AND THINKING ABOUT THAT FLT. TKOFS AT DETROIT CITY ARPT -- PARTICULARLY IN THE MLG X -- CONCERN ME MUCH MORE THAN LNDGS. I AM NOT HAPPY WITH MYSELF FOR NEGLECTING TO PLAN THIS TKOF CORRECTLY. FORTUNATELY EVERYTHING WORKED AND WE DID NOT HAVE TO ABORT THE TKOF. I PLAN TO DISCUSS THIS INCIDENT WITH MY CHIEF PLT TO MAKE SURE OTHERS DON'T MAKE THE SAME MISTAKE. SUPPLEMENTAL INFO FROM ACN 211465. I MISTAKENLY ASSUMED EVERYTHING WAS CORRECT INCLUDING THE PAPERWORK (IE; NEW RELEASE WT); HOWEVER; APPARENTLY THE NEW RELEASE SHOULD HAVE BEEN 100900 POUNDS TO REFLECT OUR PUSH WT. WE DEPARTED DET ABOUT 15 MINS LATE WITH NO PROBLEMS. I DID NOT FIND OUT ABOUT THIS MISTAKE UNTIL THE FOLLOWING WK; WHEN THE CAPT NOTIFIED ME IN LETTER FORM.