A TOTAL OF 5 MD11 ACFT WERE RELEASED FROM HVY MAINT WITH FLT CTLS OUT OF BAL DUE TO MATHEMATICAL ERROR.

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DURING A RECENT PAPERWORK AUDIT; I DISCOVERED THAT A MATHEMATICAL ERROR HAD BEEN MADE DURING THE ON ACFT FLT CTL BAL AFTER PAINT APPLICATION. FURTHER INVESTIGATION REVEALED THE SAME ERROR ON 4 OTHER ACFT. THESE ERRORS OCCURRED BTWN DEC/05 AND MAY/06. ONLY THE INSCRIBED DATA WAS INACCURATE ON 3 OF THE ACFT; BUT THE ACTUAL FLT CTL BAL WAS WITHIN LIMITS ON THOSE PLANES. THE OTHER 2 ACFT HAD A TOTAL OF 3 FLT CTLS THAT WERE CALCULATED OUTSIDE OF THEIR LIMITS. THE CUSTOMER HAS BEEN NOTIFIED. I DID REFER TO OUR SRM BUT MISSED THE DIFFERENCE BTWN THE TERMS NOSE-HVY AND TAIL-HVY; DIFFERENT FLT CTLS ON THE SAME ACFT. I INADVERTENTLY CALCULATED BOTH THE SAME. WE HAVE NOW INITIATED A PROC ENSURING THAT 2 QUALIFIED FLT CTL BAL PERSONNEL WILL INDEPENDENTLY MAKE CALCULATIONS AND CONFER BEFORE FINAL DATA IS INSCRIBED. WE ARE ALSO CREATING A FORM WITH FILL-IN BLANKS CLRLY INDICATING THE MATHEMATICAL FORMULAS/FUNCTIONS FOR EACH TYPE OF FLT CTL. THE FORM WOULD BE PRINTED OUT AND BOTH PERSONNEL INVOLVED WILL FILL IN THE BLANKS WITH THE FLT CTL ARR BAL DATA; THE SQUARE FT AREA OF THE FLT CTL; THE COATS OF PAINT APPLIED; AND THE MOMENT ARM DATA. THERE WILL BE SEPARATE FORMS FOR THE NOSE HVY AND THE TAIL HVY FLT CTLS CLRLY INDICATING THE CORRECT CALCULATIONS.