AN ACR WDB CLBED THROUGH ITS ASSIGNED ALT.

Narrative

DURING THE TKOF SEGMENT OF OUR FLT THE FOLLOWING OCCURRED: AFTER LIFTOFF FROM THE MIA ARPT; THE CAPT; WHO WAS ON HIS IOE TRAINING; CALLED FOR CLB PWR/VNAV AT 400 FT AGL. THIS IS A NORMAL CALL PER COMPANY PROCS; HOWEVER; WHEN THE THRUST MGMNT SYS AND THE PITCH MODE SYS WAS ENGAGED; THE SYS DID NOT RESPOND AS EXPECTED. THE ACFT WAS CLBING ABOUT 4000 FPM TO AN ASSIGNED ALT OF 7000 FT MSL. I ADVISED THE CAPT WE WERE NOT RECEIVING THE THRUST AND PITCH COMMANDS AND FOR HIM TO MANUALLY CTL THE ACFT. THE CAPT WAS SLOW TO RESPOND TO THE PWR REDUCTION AS WE APCHED 7000 FT MSL AND WE OVERSHOT THE ASSIGNED ALT. I TOOK CTL OF THE THRUST LEVERS AND CTL WHEEL AND PUSHED THE NOSE OVER TO RETURN TO THE ASSIGNED ALT OF 7000 FT. IN THE INTEREST OF NOT CAUSING DISCOMFORT IN ADDITION TO SAFETY CONCERNS; I DID NOT USE ABRUPT CTL FORCES. WE STARTED A DSCNT TO 7000 FT AT 7800 FT MSL. THE CTLR WAS ADVISED WE WERE LEVELING AT 7000 FT AND HE CLRED US TO 16000 FT. NO CONFLICT EXISTED NOR DID THE CTLR MENTION ANYTHING AS TO AN ALTDEV. THE REASON THE THRUST MGMNT AND PITCH MODE SYS DID NOT RESPOND PROPERLY TO THE COMMANDS GIVEN WAS BECAUSE THE FLT DIRECTORS WERE APPARENTLY NOT RESET AFTER THE PREVIOUS APCH WAS CONDUCTED. THIS WAS SUSPECTED BECAUSE THE LATERAL NAV SYS WAS ENGAGED IN THE APCH MODE. I WOULD SUGGEST THAT THE FLT DIRECTORS BE SWITCHED OFF AFTER EVERY LNDG TO PREVENT THIS SIT TO RECUR. I FEEL THIS ITEM SHOULD BE INCLUDED ON THE AFTER LNDG CHKLIST OR THE ENG SHUTDOWN CHKLIST. AT THIS TIME IT IS NOT MENTIONED ON ANY CHKLIST.