What was found
IN CRUISE FLIGHT RIGHT FUEL INDICATION WENT FROM 6,500 LBS TO 5,300 LBS AND BACK UP TO 6,500 LBS OVER THE COURSE OF ABOUT 1 MINUTE. GROUNDED - YES. PERFORMED FQIS BITE TEST REF B737-900 FIM 28-41 TASK 801, NO CURRENT FAULT OR HISTORY FAULT LOGGED, FQIS GROUND TEST PASSED, ACCOMPLISHED FUEL IMBALANCE CONDITIONAL INSPECTION REF AMM 05-51-48, NO DEFECTS OR LEAKS NOTED.