B732 FO OVERSHOOTS ASSIGNED ALT; FORGETTING HIS TYPE ACFT DOES NOT HAVE A MORE ADVANCED FMS AND DISTR BY COCKPIT TASKS.

Narrative

FO WAS FLYING THE ACFT. THE AUTOPLT WAS INOP. THE FLT WAS FROM MCI TO ATL. SOME WX IN THE AREA AND ON APCH. WE WERE IN AND OUT OF THE CLOUDS. APCH CTL CLRED US TO 6000 FT MSL. THE FO HAD THE FLT DIRECTOR SET TO GIVE A DSCNT TO THE ASSIGNED ALT. DURING THE DSCNT; THE CAPT WAS TUNING AND IDENTING NAV RADIOS AND RUNNING THE APCH CHKLIST. THE DISTRS CAUSED THE FO TO CONTINUE TO FOLLOW THE FLT DIRECTOR THROUGH THE ASSIGNED ALT OF 6000 FT MSL TO 5500 FT MSL. APCH CTL THEN ASKED US WHAT OUR ASSIGNED ALT WAS. WE WERE THEN CLRED TO 5000 FT MSL. WE SHOULD HAVE STRICTLY MONITORED THE DSCNT WHEN WITHIN 1000 FT OF LEVELOFF. WE SHOULD HAVE AN AIRPLANE WITH AN AUTOPLT THAT WORKS. IF A PLANE DOES NOT HAVE AN AUTOPLT WITH ABILITY TO LEVEL OFF; IT OUGHT TO HAVE A WARNING HORN AT 300 FT FROM ALT. SUPPLEMENTAL INFO FROM ACN 501650: THE APCH CTLR SAID THERE WAS NO CONFLICT. AN OTHERWISE UNEVENTFUL APCH AND LNDG WAS MADE. THE ACFT WE WERE FLYING THIS DAY HAS AN AUTOPLT AND FLT DIRECTOR SYS THAT IS MUCH MORE PRIMITIVE; AND LESS CAPABLE THAN ALL THE OTHER ACFT WE NORMALLY FLY. OUR HABIT PATTERNS ARE NOT CONSISTENT WITH COMPETENTLY FLYING THIS ACFT. WE SEE THIS ACFT ONCE EVERY FEW MONTHS. AS THE PNF; I WAS BUSY TUNING AND IDENTING THE ILS RADIOS AND ACCOMPLISHING THE APCH CHKLIST.