What was found
HAD A LEFT SIDE VTK FLAG AND DUAL FMC FAILURE TWICE DURING FLIGHT. BOTH TIMES RECOVERED AND CLEARED WITHIN ABOUT 30 SEC- 1 MIN. GROUNDED - YES. PER B737-900 AMM 34-61-00 THIS IS A NUISANCE ERROR, ACCOMPLISHED SENSOR CK OF BOTH L & R FMC REF FMC BITE B737-900 FIM 34-61 TASK 801 NO SENSOR FAIL. FLT FAULT HAD R FMC FAULT, ACCOMPLISHED FIM 34-61 TASK 824 WITH NO SUBSEQUENT FAULTS.