WDB RAMP WT EXCEEDED DURING TAXI.

Narrative

WHILE WAITING FOR TKOF; WE WERE INFORMED BY OUR COMPANY THAT OUR ACFT WAS TOO HVY FOR TKOF AND WE NEEDED TO RETURN TO THE GATE AND OFF-LOAD SOME 6000 LBS OF CARGO TO RETURN TO TKOF LIMITS. THE ORIGINAL WT DATA FORMS INDICATED THAT EVEN THOUGH WE WERE CLOSE TO MAX TKOF LIMITS; THE NUMBERS ADDED UP PROPERLY. AFTER OFF-LOADING APPROX 6000 LBS OF THE CARGO; THE SECOND WT DATA FORM ADDED UP PROPERLY AND WAS CLOSE TO THE ORIGINAL TKOF WT. THE PROB WAS THAT THE FIRST WT DATA FORM LISTED 120 PAX IN TOURIST. THE SECOND FORM LISTED 150 PAX IN TOURIST (ALL OTHER CABIN COUNTS REMAINED THE SAME). THE 30 PAX DIFFERENCE AMOUNTED TO THE 6000 LB DISCREPANCY. THIS PROB WAS CAUSED BY THE PERSON RPTING OR DOING THE WT AND BAL CALCULATIONS. EITHER AN OUTRIGHT ERROR IN ADDITION; RPTING; OR POSSIBLY A TYPOGRAPHICAL ERROR OF A 2 INSTEAD OF A 5 IN THE FINAL COUNT (120 VERSUS 150). THE CREW ADDED THE NUMBERS CORRECTLY; BUT WERE NOT REQUIRED NOR THOUGHT IT NECESSARY TO REQUEST A PHYSICAL HEAD COUNT PRIOR TO DEP. IN THE FUTURE; WHEN CLOSE TO MAX GROSS TKOF WT; A HEAD COUNT WILL BE A VALUABLE TOOL IN XCHKING THE ACCURACY OF THE WT DATA RPT.