DC9 CREW DISTR BY ARR ARPT NOTAMS OVERSHOT ASSIGNED ALT.

Narrative

DURING INITIAL DSCNT INTO ROC; ZOB CLRED FLT FROM FL220 TO 16000 FT. CORRECT ALT WAS SET IN THE ALT ALERTER FOLLOWING ALT AWARENESS SOP'S. DSCNT WAS COMMENCED. THE CAPT AS PF BEGAN THE APCH BRIEFING IN PREPARATION FOR AN ILS APCH TO RWY 22. WHILE DISCUSSING A NOTAM CONCERNING THE MIDDLE MARKER BEING OTS; BOTH PLTS REALIZED THAT THEY HAD EXCEEDED THE ALT CLRNC. A CORRECTIVE CLB WAS INITIATED AT 14900 FT MSL. IMMEDIATELY AFTER BEGINNING THE CLB; ATC INQUIRED AS TO THE CLRNC ALT ASSIGNMENT. THE FO RESPONDED AS TO THE ALTDEV; INCLUDING THE ALT PASSING IN THE RETURN TO 16000 FT. ATC RESPONDED WITH 'NO PROB' AND ISSUED A DISCRETIONARY CLRNC TO 11000 FT. THE DSCNT; APCH; AND LNDG PROCEEDED WITHOUT INCIDENT. RELATIVE FACTORS: 1) ALT ALERTER WAS MEL'ED. AURAL TONE WAS INOP AND ALERT LIGHTS WERE INTERMITTENT. LIGHTS DID NOT ILLUMINATE DURING THE EVENT. 2) BOTH PLTS HAD DISCUSSED THE MEL EXTENSIVELY PRIOR TO THE FLT; INCLUDING THE NECESSITY FOR EXTRA VIGILANCE IN ALT CLRNCS. EVEN SO; THE DEV OCCURRED. 3) INOP ILS EQUIP (MM) LENGTHENED THE APCH BRIEFING DISCUSSION. 4) THE EVENT ACFT DID NOT HAVE AUTOPLT ALT PRESELECT; MAKING THE LOSS OF THE ALT ALERTER VERY SERIOUS. CONSIDERATION SHOULD BE GIVEN TO REMOVING THE ALT ALERTER FROM THE MEL DUE TO ALTDEV IMPLICATIONS.