Narrative:

The captain and I received the aircraft at an outstation with 2 MEL items already listed. The pertinent one was the altitude alerter. As part of the MEL process, it was deactivated. During our arrival into sea, we briefed a practice CAT ii approach for procedural practice. As part of the approach, we coupled the autoplt to the ILS. Just before the middle marker, the autoplt went off line, but the autoplt out' light did not flash as it should. After an uneventful landing, the captain called maintenance and wrote up the autoplt approach function in the maintenance log. Because it was just the approach function that we thought was faulty, it did not seem to conflict with the altitude alerter being on the MEL. We then continued to our next destination. Nearly a week later, an assistant chief pilot called asking about the incident. He claimed that both items cannot be on the MEL at the same time. My suggestion is that for conflicting MEL items like this, the procedures should be explicit regarding whether the autoplt can still be used en route if it failed on an approach mode. Common sense indicates that a normally operating autoplt with the approach function deferred is not in conflict with the altitude alerter inoperative.

Related reports:

Google
 

Original NASA ASRS Text

Title: FOKKER F28 FLC OPERATED ACFT CONTRARY TO THE ACFT'S APPROVED MEL EQUIP LIST.

Narrative: THE CAPT AND I RECEIVED THE ACFT AT AN OUTSTATION WITH 2 MEL ITEMS ALREADY LISTED. THE PERTINENT ONE WAS THE ALT ALERTER. AS PART OF THE MEL PROCESS, IT WAS DEACTIVATED. DURING OUR ARR INTO SEA, WE BRIEFED A PRACTICE CAT II APCH FOR PROCEDURAL PRACTICE. AS PART OF THE APCH, WE COUPLED THE AUTOPLT TO THE ILS. JUST BEFORE THE MIDDLE MARKER, THE AUTOPLT WENT OFF LINE, BUT THE AUTOPLT OUT' LIGHT DID NOT FLASH AS IT SHOULD. AFTER AN UNEVENTFUL LNDG, THE CAPT CALLED MAINT AND WROTE UP THE AUTOPLT APCH FUNCTION IN THE MAINT LOG. BECAUSE IT WAS JUST THE APCH FUNCTION THAT WE THOUGHT WAS FAULTY, IT DID NOT SEEM TO CONFLICT WITH THE ALT ALERTER BEING ON THE MEL. WE THEN CONTINUED TO OUR NEXT DEST. NEARLY A WK LATER, AN ASSISTANT CHIEF PLT CALLED ASKING ABOUT THE INCIDENT. HE CLAIMED THAT BOTH ITEMS CANNOT BE ON THE MEL AT THE SAME TIME. MY SUGGESTION IS THAT FOR CONFLICTING MEL ITEMS LIKE THIS, THE PROCS SHOULD BE EXPLICIT REGARDING WHETHER THE AUTOPLT CAN STILL BE USED ENRTE IF IT FAILED ON AN APCH MODE. COMMON SENSE INDICATES THAT A NORMALLY OPERATING AUTOPLT WITH THE APCH FUNCTION DEFERRED IS NOT IN CONFLICT WITH THE ALT ALERTER INOP.

Data retrieved from NASA's ASRS site as of July 2007 and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.