Narrative:

Prior to departure the copilot discovered the takeoff warning horn on the left throttle inoperative. The warning horn on the right throttle operated normally. We called maintenance and consulted the MEL. Under flight controls we read 'takeoff warning horn must be operative.' then checked with maintenance headquarters and they advised that the airplane can be dispatched with this item deferred. This item is deferred when maintenance sends a computer message to the station authorizing such action. The message is signed by a maintenance authority. The message stated that the deferral assumes the normal operation of the warning system on the opp throttle. Our MEL does not specifically address the fact that each throttle has a warning horn--must they both be operative? I chose to allow that the authority of maintenance in this question and decided to depart the station with the maintenance deferral stapled to the log book page. It stated, in part, 'authorization to defer warning horn on left throttle provided warning horn on right throttle is normal.' I have been advised that my chosen action was not correct, in other words, I should not have accepted the airplane until the malfunction was repaired and the item cleared from the log. Looking back on it now I have to agree that the airplane should have been taken OTS at that station. What I am asking for is more concise text in the MEL. A text that will cover the situation we found ourselves in. A text that will offer the possible alternatives to these malfunctions. Anything less is guesswork on our part.

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Original NASA ASRS Text

Title: FLT CREW QUESTIONS MINIMUM EQUIPMENT LIST INTERPRETATION.

Narrative: PRIOR TO DEP THE COPLT DISCOVERED THE TKOF WARNING HORN ON THE LEFT THROTTLE INOP. THE WARNING HORN ON THE RIGHT THROTTLE OPERATED NORMALLY. WE CALLED MAINT AND CONSULTED THE MEL. UNDER FLT CONTROLS WE READ 'TKOF WARNING HORN MUST BE OPERATIVE.' THEN CHKED WITH MAINT HEADQUARTERS AND THEY ADVISED THAT THE AIRPLANE CAN BE DISPATCHED WITH THIS ITEM DEFERRED. THIS ITEM IS DEFERRED WHEN MAINT SENDS A COMPUTER MESSAGE TO THE STATION AUTHORIZING SUCH ACTION. THE MESSAGE IS SIGNED BY A MAINT AUTHORITY. THE MESSAGE STATED THAT THE DEFERRAL ASSUMES THE NORMAL OPERATION OF THE WARNING SYS ON THE OPP THROTTLE. OUR MEL DOES NOT SPECIFICALLY ADDRESS THE FACT THAT EACH THROTTLE HAS A WARNING HORN--MUST THEY BOTH BE OPERATIVE? I CHOSE TO ALLOW THAT THE AUTHORITY OF MAINT IN THIS QUESTION AND DECIDED TO DEPART THE STATION WITH THE MAINT DEFERRAL STAPLED TO THE LOG BOOK PAGE. IT STATED, IN PART, 'AUTHORIZATION TO DEFER WARNING HORN ON LEFT THROTTLE PROVIDED WARNING HORN ON RIGHT THROTTLE IS NORMAL.' I HAVE BEEN ADVISED THAT MY CHOSEN ACTION WAS NOT CORRECT, IN OTHER WORDS, I SHOULD NOT HAVE ACCEPTED THE AIRPLANE UNTIL THE MALFUNCTION WAS REPAIRED AND THE ITEM CLRED FROM THE LOG. LOOKING BACK ON IT NOW I HAVE TO AGREE THAT THE AIRPLANE SHOULD HAVE BEEN TAKEN OTS AT THAT STATION. WHAT I AM ASKING FOR IS MORE CONCISE TEXT IN THE MEL. A TEXT THAT WILL COVER THE SITUATION WE FOUND OURSELVES IN. A TEXT THAT WILL OFFER THE POSSIBLE ALTERNATIVES TO THESE MALFUNCTIONS. ANYTHING LESS IS GUESSWORK ON OUR PART.

Data retrieved from NASA's ASRS site as of August 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.