CORP SMT HAS ALTDEV ON DSCNT.

Narrative

WHILE ENRTE TO LAL ON JAN/XX/95; APPROX XX00 PM; I WAS GIVEN CLRNC TO DSND TO 6000 FT. AT THE TIME I WAS CIRCUMNAVIGATING A LINE OF EMBEDDED TSTMS OF LEVEL 3-4 INTENSITY ON MY RADAR; I WAS PENETRATING A SMALL CELL ON THE WEAK LIGHT RAIN SIDE. THE TURB THE LAST FEW MI WAS CONTINUOUS MODERATE; OCCASIONALLY HVY. AS I STARTED THE DSCNT; I RESET THE ALT ALERT AND I PRESUME THE ARM BUTTON. AT THE SAME TIME; TFC WAS CALLED OUT APPROX 10 MI AWAY AT 5000 FT. AT THAT TIME I NOTICED I WAS DSNDING THROUGH 5400 FT. I IMMEDIATELY CLBED BACK UP TO 6000 FT; LOOKED AT THE ALERTER AND SAW 6000 FT SET BUT THE ARMED LIGHT NOT ON. THE AUTOPLT WHICH WAS ON AT THE TIME DIDN'T CAPTURE ALT! WHY? 1) I DIDN'T ARM IT OR 2) IT DIDN'T CAPTURE BECAUSE OF TURB OR ME BUMPING THE TRIM IN THE TURB KNOCKING IT OFF? WHATEVER; I BELIEVE IT'S MY RESPONSIBILITY TO MONITOR ALL FUNCTIONS AND IN THE MIDST OF ALL THAT WAS HAPPENING; I MISSED THE ALT CAPTURE. I FAILED TO MONITOR THE ENGAGEMENT AND DIDN'T HEAR THE BELL. CTR ASKED ME IF I WAS LEVEL 6000 FT; WHICH NOW I WAS; I REPLIED AFFIRMATIVE LEVEL 6000 FT. THEY SAID MODE C INDICATED 5400 FT. I SAID ROGER AND SAID I'LL TRY ANOTHER XPONDER; WHICH I DID. THEY SAID IT SHOWED 6000 FT; AND ASKED ME TO VERIFY I WAS LEVEL AT 6000 FT; AS THEY HAVE TO WRITE IT DOWN. I SAID I WAS LEVEL 6000 FT. NOTHING ELSE WAS SAID AS I WAS HANDED OFF TO ANOTHER CTLR. IN CONCLUSION; IN A HIGH WORKLOAD ENVIRONMENT; SITUATIONAL AWARENESS CAN EASILY BE LOST. PLT MUST BE SURE TO REVERIFY ALL PERTINENT ITEMS.