Narrative:

Both pilots noted unusually long takeoff roll and PF noted nose heavy feel during rotation. During departure, ATC stopped west flow due to WX and instructed us to slow to 250 KTS at 17000 ft MSL. We got an 'alpha speed' warning which surprised us because our closeout weight was approximately 146000 pounds. South&left unaccelerated speed to remove 'alpha speed' warning was 255 KTS which corresponded to a gross weight of 154000 pounds. This indicated an actual TOGW of approximately 157000 pounds. Contacted dispatch and requested offload audit at dfw. Arriving dfw, checked alpha speed again over karla intersection at 239 KTS at 11000 ft MSL corresponding to gross weight of 136000 pounds. Approach bugs were set for 136000 pounds with 40 degree flaps and stabilized approach required 1.29 EPR +/-.001. I believe approach into ewr on prior flight also required higher than anticipated 1.23 EPR for stabilized 40 degree flap approach. Suspect possible error in zero fuel weight of aircraft. Briefed captain on next leg to try and give further feedback. Supplemental information from acn 617184: we cannot actually say we were overweight, just performed overweight. Maybe aoa is off, maybe load is wrong. Passenger count was right on actual at 120.

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Original NASA ASRS Text

Title: 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.

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.