AIRBUS DETAILS THE INACCURACIES IN HIS ACR'S FUEL PLANNING COMPUTER PROGRAM.

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FLT PLAN CALCULATED FUEL BURN INCORRECTLY. FLT PLAN TIME AND DISTANCE DID NOT MATCH FILED ROUTING. FLT PLAN FUEL CALCULATIONS UNDERSTATED FLYING DISTANCE BY 51 MI (OF LOW ALT FLYING) WHICH UNDERSTATED FUEL BURN BY ABOUT 1000 LBS. DISCUSSED FUEL SHORTFALL AND ENRTE WX WITH DISPATCHER BEFORE DEP. JOINTLY DECIDED TO TOP OFF FUEL ADDING 1300 LBS. ACTUAL FUEL BURN EXCEEDED PLANNED BURN BY 1700 LBS. PLANNED BURN 33600 LBS. ACTUAL BURN TKOF TO TOUCHDOWN 35300 LBS. 5-7 MINS EXTRA FLYING TIME DUE TO TSTM DEVS. ANALYSIS INDICATES PLANNED BURN ON FLT PLAN WAS INACCURATE FOR 2 REASONS: 1) ROUTING TO FIRST FIX PROB -- FLT PLAN CALCULATED THE DISTANCE FOR THE FIRST SEGMENT AS A STRAIGHT LINE FROM ZZZ TO XXXXX INTXN (13 FLYING MI; MAGNETIC COURSE 112). THE FILED ROUTING HOWEVER WAS THE SID WHICH RTES US FOR A TOTAL FLYING DISTANCE OF 26 MI. 2) ROUTING FROM LAST FIX PROB -- LAST SEGMENT OF THE FLT PLAN SHOWED A FLYING DISTANCE OF 14 MI DIRECT FROM YYYYY TO ZZZ1 ON A 157 MAGNETIC COURSE. THE FILED ROUTING WAS THE STAR ARR FOR APPROX FLYING DISTANCE OF 52 MI. FLT PLAN TIME AND FUEL CALCULATIONS MUST CORRESPOND TO FILED RTE.