Narrative:

After departure with the aircraft cleaned up, the forward leading edge flap transit light flickered on and off. This was accompanied by the illumination of the overhead annunciator for the #3 leading edge flap. No roll was encountered and the leading edge flap was visually checked up. Immediately called maintenance and specifically told them that we had a leading edge flap annunciator problem. They told us to press on to destination. Next, called dispatch and they agreed. After discussion about how to interpretation a poorly worded MEL, we agreed and pressed on. Landed without incident with all leading edge devices and indications normal. Received an en route MEL 27-4B from maintenance control and departed for home. Again, all leading edge devices and indications were normal for the departure. Only when the leading edge flaps were up, did the indication problem manifest itself. Discovered 2 days later that maintenance had misapplied the MEL and the aircraft was grounded until the malfunctioning switch was repaired. As flight crew, we are reliant on maintenance and dispatch to help us interpretation how MEL's are applied. This particular MEL begins by referring to any leading edge devices (flaps and slats) and then refers you to another paragraph if any leading edge device indications are at fault. The paragraph referred to only discusses leading edge slat indication malfunctions. So, are leading edge flap indications covered or not? I specifically asked this question to maintenance on the initial radio call. The reply was that leading edge flaps were covered as well. So with maintenance and dispatch concurrence, and knowing that the leading edge flap was up and would extend and indicate normally for landing and takeoff, we decided to press on.

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Original NASA ASRS Text

Title: A B737-200 WITH A LEADING EDGE FLAP WARNING LIGHT PROB DEFERRED WAS ALLOWED TO CONTINUE IN SVC IN CONFLICT WITH THE MEL.

Narrative: AFTER DEP WITH THE ACFT CLEANED UP, THE FORWARD LEADING EDGE FLAP TRANSIT LIGHT FLICKERED ON AND OFF. THIS WAS ACCOMPANIED BY THE ILLUMINATION OF THE OVERHEAD ANNUNCIATOR FOR THE #3 LEADING EDGE FLAP. NO ROLL WAS ENCOUNTERED AND THE LEADING EDGE FLAP WAS VISUALLY CHKED UP. IMMEDIATELY CALLED MAINT AND SPECIFICALLY TOLD THEM THAT WE HAD A LEADING EDGE FLAP ANNUNCIATOR PROB. THEY TOLD US TO PRESS ON TO DEST. NEXT, CALLED DISPATCH AND THEY AGREED. AFTER DISCUSSION ABOUT HOW TO INTERP A POORLY WORDED MEL, WE AGREED AND PRESSED ON. LANDED WITHOUT INCIDENT WITH ALL LEADING EDGE DEVICES AND INDICATIONS NORMAL. RECEIVED AN ENRTE MEL 27-4B FROM MAINT CTL AND DEPARTED FOR HOME. AGAIN, ALL LEADING EDGE DEVICES AND INDICATIONS WERE NORMAL FOR THE DEP. ONLY WHEN THE LEADING EDGE FLAPS WERE UP, DID THE INDICATION PROB MANIFEST ITSELF. DISCOVERED 2 DAYS LATER THAT MAINT HAD MISAPPLIED THE MEL AND THE ACFT WAS GNDED UNTIL THE MALFUNCTIONING SWITCH WAS REPAIRED. AS FLC, WE ARE RELIANT ON MAINT AND DISPATCH TO HELP US INTERP HOW MEL'S ARE APPLIED. THIS PARTICULAR MEL BEGINS BY REFERRING TO ANY LEADING EDGE DEVICES (FLAPS AND SLATS) AND THEN REFERS YOU TO ANOTHER PARAGRAPH IF ANY LEADING EDGE DEVICE INDICATIONS ARE AT FAULT. THE PARAGRAPH REFERRED TO ONLY DISCUSSES LEADING EDGE SLAT INDICATION MALFUNCTIONS. SO, ARE LEADING EDGE FLAP INDICATIONS COVERED OR NOT? I SPECIFICALLY ASKED THIS QUESTION TO MAINT ON THE INITIAL RADIO CALL. THE REPLY WAS THAT LEADING EDGE FLAPS WERE COVERED AS WELL. SO WITH MAINT AND DISPATCH CONCURRENCE, AND KNOWING THAT THE LEADING EDGE FLAP WAS UP AND WOULD EXTEND AND INDICATE NORMALLY FOR LNDG AND TKOF, WE DECIDED TO PRESS ON.

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.