As reported to the FAA. Reports are unverified, and codes are left as the FAA publishes them.
What was found
CREW REPORT MOMENTARY FMC DROP. VTK ON NAV DISPLAY, LEFT SIDE. GROUNDED - YES. REF B737-800 FIM 34-61 TASK 836 RESET FMCS 1 & 2. NO FAULTS NOTED. VTK FLAGS NOT PRESENT. NO FURTHER ACTIONS REQUIRED AT THIS TIME. 2 MIG 51-A INSTALLED AND REMOVED.