What was found
ON ARRIVAL OF AIRCRAFT FLIGHT TAI-396 TO MGA FROM SAL, THE PILOT REPORTED AUTO BRAKE SYSTEM FAILURE, THE AIRCRAFT WAS DECLARED AOG. PER TSM 32-42-00, FOUND TACHOMETER NR 3 INOPERATIVE. REPLACED AND PERFORMED OPERATIONAL TEST AS PER AMM 32-42-00 WITH NO DUPLICATION OF FAILURE. THE AIRCRAFT WAS RETURNED TO SERVICE.