What was found
DURING CRUISE DUEL FMC FAIL. VTK ON BOTH CA AND FO ND. AFTER A FEW MINUTES IT CAME BACK AND THEN FAILED AGAIN. IT CAME BACK AND SEEMED TO WORK OK AFTER FMC WAS RELOADED THE SECOND TIME. ALSO "LDG ALT" FLAG WAS ILLUMINATED THEN WENT AWAY. ACFT GROUNDED. ACCOMPLISHED FMCS BITE IAW FIM 34-61 TASK 801, SENSOR DATA SHOWED NO CURRENT FAULTS. FMC SOFTWARE CONFIG GOOD, IAW AMM 34-61-00-750-801. IAW FIM 34-61 TASK 837, INFLIGHT FAULT WAS A FMC PROGRAM FAULT THAT OCCURRED WHEN THE FMC WAS UNABLE TO EXECUTE A SOFTWARE INSTRUCTION AND THE FMC SHOULD BE LEFT IN SERVICE.