What was found
THREE TIMES DURING FLIGHT, EXPERIENCED DUAL FMC FAILURE. ALL THREE EVENTS STARTED ON THE CAPTAIN`S SIDE AND ONE MINUTE LATER OCCURRED ON THE FIRST OFFICER`S SIDE. ALL THREE EVENTS SEEMED TO CLEAR THEMSELVES AFTER APPROXIMATELY 5 MINUTES. NO OCCURRENCES DURING THE LAST 1 1/2 HRS OF FLIGHT. ACFT GROUNDED. PERFORMED FIM 34-61, TASK 801, FMS BITE PROCEDURE. CHECKED GOOD. INFLT FAULT FOR LAST FLT, BOTH FMC FAULTED EACH OTHER WITH 300-6R ENTERED, BOTH FMC COMPUTERS HAD A PGM FAULT. PERFORMED FIM 34-61, TASK 807 FOR PGM FAULT, OPS NORMAL, INTERMITTENT FAULT. FMC SYSTEM OPS TESTED GOOD IAW AMM 34-61-00.