Narrative:

Departing ZZZ aircraft ground interrupted due to 'engine' light illuminated on 6 pack light on recall. #2 thrust reverser on placard per MEL. I was working as the outside lead mechanic and an avionics technician was dispatched to the aircraft. I arrived at the jetbridge and found the technician on the phone with maintenance control. The question being asked was if this would be a normal condition due to the fact the 'reverser' light was illuminated on the overhead panel. At this time there was no clear answer to this question. We proceeded by putting the aircraft back into normal confign; ie; reversing all steps taken when MEL was issued. Upon reversing the procedure manual it was discovered step 2 had not been performed. These steps involve removing connectors D1008 and D1016 from the right and left sync locks. We verified that this would have been the correct procedure to follow because after reversing all steps of the procedure manual we discovered the thrust reversers would not deploy or stow with hydraulic power. We accomplished the procedure in its entirety for an inoperative thrust reverser. However; the reverser light was still illuminated on the overhead. Thus the 'engine' light would still illuminate on recall of the 6 pack. We received an ACARS message from maintenance control explaining this was a normal condition. We reviewed MEL 'engine 2 thrust reverser flight deck indication;' the print clearly shows and is noted by 'note 1' -- 'if a fault occurs when the thrust reverser is stowed; then the reverser fault light will stay on until the fault is gone.' this was the mechanical situation present. PIREP was signed off by me as a normal condition and the aircraft was dispatched. The problem is the MEL doesn't specify that this condition can exist to the operational crews; ie; 'engine' light on recall. And/or; there's no additional procedure in the maintenance manual for opening the circuit breaker C1004 'engine 2 thrust reverser ind' to clear this condition. The placard was originally applied at ZZZZ; however for whatever reason the above steps were not completed or had been reversed at some point. Callback conversation with reporter revealed the following information: reporter stated the original write-up stated the #2 engine would not go into reverse (deploy) upon landing. This led to a deferral for the #2 engine reverser as inoperative; per their MEL procedures. However; the reverser fault light on the aft overhead panel would stay on. This was normal; except; whenever the flight crew pressed the '6-pack' lights on the fwd glare shield to recall previous alerts; then the 'engine' light would also come on. Nothing in their MEL procedures had any language or verbiage noting this was also normal and would happen each time the '6-pack' was pressed (or recalled). This was due to the fact that any time the engine accessory unit (eau) showed a fault (faulted); in this case; the reverser would not deploy; then not only would the reverser light on the aft overhead panel stay lit; but the '6-pack' light for the 'engine' would also come on. The reverser handle on the #2 engine throttle was safety-wired; the two sync-lock connectors were disconnected and the 4 lock-out bolts (2 on each reverser half sleeve) were installed as part of the deferral procedure. Reporter also stated his company has reviewed their MEL language regarding the reverser lights and will make changes. Appears boeing's master minimum equipment list (mmel); has the appropriate language addressing this issue and this verbiage was left out of his carrier's MEL.

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Original NASA ASRS Text

Title: A B737-800 LEAD MECHANIC REPORTS OF HIS CARRIER'S MEL DEFERRAL PROCEDURE LANGUAGE DOES NOT TELL FLIGHT CREWS THAT THE 'ENG' LIGHT ON THE 'SIX-PACK' WILL ILLUMINATE WHEN LIGHTS ARE PRESSED FOR RECALL.

Narrative: DEPARTING ZZZ ACFT GND INTERRUPTED DUE TO 'ENG' LIGHT ILLUMINATED ON 6 PACK LIGHT ON RECALL. #2 THRUST REVERSER ON PLACARD PER MEL. I WAS WORKING AS THE OUTSIDE LEAD MECH AND AN AVIONICS TECHNICIAN WAS DISPATCHED TO THE ACFT. I ARRIVED AT THE JETBRIDGE AND FOUND THE TECHNICIAN ON THE PHONE WITH MAINT CTL. THE QUESTION BEING ASKED WAS IF THIS WOULD BE A NORMAL CONDITION DUE TO THE FACT THE 'REVERSER' LIGHT WAS ILLUMINATED ON THE OVERHEAD PANEL. AT THIS TIME THERE WAS NO CLR ANSWER TO THIS QUESTION. WE PROCEEDED BY PUTTING THE ACFT BACK INTO NORMAL CONFIGN; IE; REVERSING ALL STEPS TAKEN WHEN MEL WAS ISSUED. UPON REVERSING THE PROC MANUAL IT WAS DISCOVERED STEP 2 HAD NOT BEEN PERFORMED. THESE STEPS INVOLVE REMOVING CONNECTORS D1008 AND D1016 FROM THE R AND L SYNC LOCKS. WE VERIFIED THAT THIS WOULD HAVE BEEN THE CORRECT PROC TO FOLLOW BECAUSE AFTER REVERSING ALL STEPS OF THE PROC MANUAL WE DISCOVERED THE THRUST REVERSERS WOULD NOT DEPLOY OR STOW WITH HYD PWR. WE ACCOMPLISHED THE PROC IN ITS ENTIRETY FOR AN INOP THRUST REVERSER. HOWEVER; THE REVERSER LIGHT WAS STILL ILLUMINATED ON THE OVERHEAD. THUS THE 'ENG' LIGHT WOULD STILL ILLUMINATE ON RECALL OF THE 6 PACK. WE RECEIVED AN ACARS MESSAGE FROM MAINT CTL EXPLAINING THIS WAS A NORMAL CONDITION. WE REVIEWED MEL 'ENG 2 THRUST REVERSER FLT DECK INDICATION;' THE PRINT CLEARLY SHOWS AND IS NOTED BY 'NOTE 1' -- 'IF A FAULT OCCURS WHEN THE THRUST REVERSER IS STOWED; THEN THE REVERSER FAULT LIGHT WILL STAY ON UNTIL THE FAULT IS GONE.' THIS WAS THE MECHANICAL SITUATION PRESENT. PIREP WAS SIGNED OFF BY ME AS A NORMAL CONDITION AND THE ACFT WAS DISPATCHED. THE PROB IS THE MEL DOESN'T SPECIFY THAT THIS CONDITION CAN EXIST TO THE OPERATIONAL CREWS; IE; 'ENG' LIGHT ON RECALL. AND/OR; THERE'S NO ADDITIONAL PROC IN THE MAINT MANUAL FOR OPENING THE CIRCUIT BREAKER C1004 'ENG 2 THRUST REVERSER IND' TO CLR THIS CONDITION. THE PLACARD WAS ORIGINALLY APPLIED AT ZZZZ; HOWEVER FOR WHATEVER REASON THE ABOVE STEPS WERE NOT COMPLETED OR HAD BEEN REVERSED AT SOME POINT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THE ORIGINAL WRITE-UP STATED THE #2 ENGINE WOULD NOT GO INTO REVERSE (DEPLOY) UPON LANDING. THIS LED TO A DEFERRAL FOR THE #2 ENG REVERSER AS INOP; PER THEIR MEL PROCEDURES. HOWEVER; THE REVERSER FAULT LIGHT ON THE AFT OVERHEAD PANEL WOULD STAY ON. THIS WAS NORMAL; EXCEPT; WHENEVER THE FLIGHT CREW PRESSED THE '6-PACK' LIGHTS ON THE FWD GLARE SHIELD TO RECALL PREVIOUS ALERTS; THEN THE 'ENG' LIGHT WOULD ALSO COME ON. NOTHING IN THEIR MEL PROCEDURES HAD ANY LANGUAGE OR VERBIAGE NOTING THIS WAS ALSO NORMAL AND WOULD HAPPEN EACH TIME THE '6-PACK' WAS PRESSED (OR RECALLED). THIS WAS DUE TO THE FACT THAT ANY TIME THE ENGINE ACCESSORY UNIT (EAU) SHOWED A FAULT (FAULTED); IN THIS CASE; THE REVERSER WOULD NOT DEPLOY; THEN NOT ONLY WOULD THE REVERSER LIGHT ON THE AFT OVERHEAD PANEL STAY LIT; BUT THE '6-PACK' LIGHT FOR THE 'ENG' WOULD ALSO COME ON. THE REVERSER HANDLE ON THE #2 ENG THROTTLE WAS SAFETY-WIRED; THE TWO SYNC-LOCK CONNECTORS WERE DISCONNECTED AND THE 4 LOCK-OUT BOLTS (2 ON EACH REVERSER HALF SLEEVE) WERE INSTALLED AS PART OF THE DEFERRAL PROCEDURE. REPORTER ALSO STATED HIS COMPANY HAS REVIEWED THEIR MEL LANGUAGE REGARDING THE REVERSER LIGHTS AND WILL MAKE CHANGES. APPEARS BOEING'S MASTER MINIMUM EQUIPMENT LIST (MMEL); HAS THE APPROPRIATE LANGUAGE ADDRESSING THIS ISSUE AND THIS VERBIAGE WAS LEFT OUT OF HIS CARRIER'S MEL.

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.