AN ACR BE99 FLC COMPLAINS THAT THE FUEL GAUGES ON BE99 ACFT ARE INACCURATE AND THEY INCREASE IN ERROR AS THE FUEL QUANTITY INCREASES SO PREFLT FUEL READINGS ARE OFTEN ERRONEOUS.

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I AM A BE99 CAPT AND HAVE FLOWN IN THAT CAPACITY FOR 1 YR NOW; WHERE I'VE ACCRUED NEARLY 1000 HRS. PIC TURBOPROP TIME. ANYHOW; I KNOW MY ACFT WELL AND I CERTAINLY KNOW HOW TO CALCULATE 'FUEL LOADS' PROFICIENTLY. ON THE EVENING OF JAN/TUE/98; AT APPROX XA30 LMST I HAD OUR FUELER ADD 120 GALS OF JET A TO OUR BE99. WE HAD ROUGHLY 1000 LBS OF FUEL PRIOR TO BEING REFUELED. THE CALCULATION IS SIMPLE: WE HAD 1000 LBS FUEL AND WANTED 1800 LBS FUEL. HENCE; THE DIFFERENCE IS 800 LBS FUEL. SO; DIVIDE 800 LBS BY 2 EQUALS 400 LBS. AND THEN ADD 400 LBS TO YOUR ORIGINAL 800 LBS; AND YOU GET 1200 LBS. THEN; YOU JUST DROP A ZERO AND THE FUEL YOU'LL WANT TO ADD IS 120 GALS. AFTER DOING SO; MY FUEL GAUGES INDICATED ABOUT 2000 LBS (200 LBS FUEL EXTRA). MY WT AND BAL REFLECTED 1800 LBS FUEL; HOWEVER. NOW; THIS ERROR IS COMMON IN MOST OF OUR ACFT; AT LEAST THE ONES I AM INTIMATELY INVOLVED WITH. AND; THE ERROR BECOMES GREATER AS MORE AND MORE FUEL IS ADDED TO THE ACFT. ALSO; THE FUEL GAUGES WILL COMMONLY INDICATE DIFFERENTLY FROM WHEN YOU SHUT THE ENGS DOWN TO FLYING IT THE NEXT DAY. DEPENDING UPON HOW LONG THE PLANE HAS BEEN SITTING. AND I ALWAYS THOUGHT THAT THIS WAS NORMAL FOR THE BE99. EITHER WE NEED NEWLY CALIBRATED FUEL GAUGES OR ELSE THIS TYPE OF OCCURRENCE WILL CONTINUE TO HAPPEN.