Narrative:

We were dispatched on flight X on dec/sun/06 on aircraft X. The dispatch release disclosed an MEL 21-32 with the title of 'control cabin temperature control inoperative.' upon completion of engine start after pushback we attempted to comply with the MEL system operations verification procedure. Upon selecting 'recall' we expected to see the affected air-conditioning pack light and master caution lights illuminated. The verification procedure would then have us push the master caution light to reset the system and extinguish the light. According to the procedure this was positive verification that the backup system was operational and functioning properly. None of the lights illuminated as advertised per the procedure. We analyzed the MEL manual again to determine if we were conducting the procedure properly. This investigation revealed that the issued MEL's title was incorrect and that an alternative MEL (21-21C) should have been utilized. The error revealed was that the correct title was used but the wrong number MEL was issued. Upon return to the gate we debriefed maintenance on the matter and the response was to issue the correct MEL (21-21C). Upon review of the compliance procedure with the maintenance technician on board we were unable to successfully accomplish the procedure as specified in the MEL. At this point a supervisor intervened and adamantly stipulated that this outcome was common on this MEL and that we could comfortably take the aircraft as is. We attempted to comply with the verification procedure in the new MEL and were unable to do so. The maintenance supervisor insisted that this was a normal outcome and that we should accept the aircraft as is with the new MEL. We insisted that the documentation be corrected to reflect these exceptions and the response from maintenance was that they would not alter the published MEL procedure. As the crew we stipulated that there were 2 available options to resolve the issue: fix the aircraft or provide written guidance to address the situation in order to enable aircrew compliance. After a 2 hour delay the aircraft was repaired. Upon further analysis we discovered that the original MEL had been issued on dec/thu/06 and that the aircraft had been improperly dispatched for 3 days.

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Original NASA ASRS Text

Title: A B737-400 CTL CABIN TEMP CTL WAS IMPROPERLY DEFERRED WITH WRONG MEL PROCS AND REF. CREW UNABLE TO MAKE REQUIRED OPS CHK.

Narrative: WE WERE DISPATCHED ON FLT X ON DEC/SUN/06 ON ACFT X. THE DISPATCH RELEASE DISCLOSED AN MEL 21-32 WITH THE TITLE OF 'CTL CABIN TEMP CTL INOP.' UPON COMPLETION OF ENG START AFTER PUSHBACK WE ATTEMPTED TO COMPLY WITH THE MEL SYS OPS VERIFICATION PROC. UPON SELECTING 'RECALL' WE EXPECTED TO SEE THE AFFECTED AIR-CONDITIONING PACK LIGHT AND MASTER CAUTION LIGHTS ILLUMINATED. THE VERIFICATION PROC WOULD THEN HAVE US PUSH THE MASTER CAUTION LIGHT TO RESET THE SYS AND EXTINGUISH THE LIGHT. ACCORDING TO THE PROC THIS WAS POSITIVE VERIFICATION THAT THE BACKUP SYS WAS OPERATIONAL AND FUNCTIONING PROPERLY. NONE OF THE LIGHTS ILLUMINATED AS ADVERTISED PER THE PROC. WE ANALYZED THE MEL MANUAL AGAIN TO DETERMINE IF WE WERE CONDUCTING THE PROC PROPERLY. THIS INVESTIGATION REVEALED THAT THE ISSUED MEL'S TITLE WAS INCORRECT AND THAT AN ALTERNATIVE MEL (21-21C) SHOULD HAVE BEEN UTILIZED. THE ERROR REVEALED WAS THAT THE CORRECT TITLE WAS USED BUT THE WRONG NUMBER MEL WAS ISSUED. UPON RETURN TO THE GATE WE DEBRIEFED MAINT ON THE MATTER AND THE RESPONSE WAS TO ISSUE THE CORRECT MEL (21-21C). UPON REVIEW OF THE COMPLIANCE PROC WITH THE MAINT TECHNICIAN ON BOARD WE WERE UNABLE TO SUCCESSFULLY ACCOMPLISH THE PROC AS SPECIFIED IN THE MEL. AT THIS POINT A SUPVR INTERVENED AND ADAMANTLY STIPULATED THAT THIS OUTCOME WAS COMMON ON THIS MEL AND THAT WE COULD COMFORTABLY TAKE THE ACFT AS IS. WE ATTEMPTED TO COMPLY WITH THE VERIFICATION PROC IN THE NEW MEL AND WERE UNABLE TO DO SO. THE MAINT SUPVR INSISTED THAT THIS WAS A NORMAL OUTCOME AND THAT WE SHOULD ACCEPT THE ACFT AS IS WITH THE NEW MEL. WE INSISTED THAT THE DOCUMENTATION BE CORRECTED TO REFLECT THESE EXCEPTIONS AND THE RESPONSE FROM MAINT WAS THAT THEY WOULD NOT ALTER THE PUBLISHED MEL PROC. AS THE CREW WE STIPULATED THAT THERE WERE 2 AVAILABLE OPTIONS TO RESOLVE THE ISSUE: FIX THE ACFT OR PROVIDE WRITTEN GUIDANCE TO ADDRESS THE SITUATION IN ORDER TO ENABLE AIRCREW COMPLIANCE. AFTER A 2 HR DELAY THE ACFT WAS REPAIRED. UPON FURTHER ANALYSIS WE DISCOVERED THAT THE ORIGINAL MEL HAD BEEN ISSUED ON DEC/THU/06 AND THAT THE ACFT HAD BEEN IMPROPERLY DISPATCHED FOR 3 DAYS.

Data retrieved from NASA's ASRS site as of January 2009 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.