MD82 APPEARS TO HAVE BEEN OVERLOADED BY APPROX 11000 LBS CAUSING AN 'ALPHA SPD' WARNING RESOLVED BY INCREASING THEIR APCH SPD.

Narrative

BOTH PLTS NOTED UNUSUALLY LONG TKOF ROLL AND PF NOTED NOSE HVY FEEL DURING ROTATION. DURING DEP; ATC STOPPED W FLOW DUE TO WX AND INSTRUCTED US TO SLOW TO 250 KTS AT 17000 FT MSL. WE GOT AN 'ALPHA SPD' WARNING WHICH SURPRISED US BECAUSE OUR CLOSEOUT WT WAS APPROX 146000 LBS. S&L UNACCELERATED SPD TO REMOVE 'ALPHA SPD' WARNING WAS 255 KTS WHICH CORRESPONDED TO A GROSS WT OF 154000 LBS. THIS INDICATED AN ACTUAL TOGW OF APPROX 157000 LBS. CONTACTED DISPATCH AND REQUESTED OFFLOAD AUDIT AT DFW. ARRIVING DFW; CHKED ALPHA SPD AGAIN OVER KARLA INTXN AT 239 KTS AT 11000 FT MSL CORRESPONDING TO GROSS WT OF 136000 LBS. APCH BUGS WERE SET FOR 136000 LBS WITH 40 DEG FLAPS AND STABILIZED APCH REQUIRED 1.29 EPR +/-.001. I BELIEVE APCH INTO EWR ON PRIOR FLT ALSO REQUIRED HIGHER THAN ANTICIPATED 1.23 EPR FOR STABILIZED 40 DEG FLAP APCH. SUSPECT POSSIBLE ERROR IN ZERO FUEL WT OF ACFT. BRIEFED CAPT ON NEXT LEG TO TRY AND GIVE FURTHER FEEDBACK. SUPPLEMENTAL INFO FROM ACN 617184: WE CANNOT ACTUALLY SAY WE WERE OVERWT; JUST PERFORMED OVERWT. MAYBE AOA IS OFF; MAYBE LOAD IS WRONG. PAX COUNT WAS RIGHT ON ACTUAL AT 120.