Narrative:

On feb/fri/06; while working in the center; I issued and assigned to field personnel an MEL to permit deferral of maintenance on #3 engine thrust reverser. Review of the aircraft logbook during preflight at the next station revealed that the autospoilers had been previously deferred on feb/tue/06. MEL permits thrust reverser deferral; provided the autospoiler system operates normally. Even though not intentional; I failed to meet the requirements of the MEL in assuring that the autospoilers were operating normally prior to assigning this deferred maintenance item. This was discovered by flight crew personnel and reported to the airline technical center. The technical center representative on duty contacted and worked with line maintenance personnel to repair the autospoilers prior to the aircraft being released into service. Contributing to this error was the failure on my part to thoroughly review the deferred maintenance listing for the aircraft affected. The MEL clearly states what conditions that must be met in order to deactivate a thrust reverser. I relied on memory to determine the appropriate MEL reference and did not refer to the MEL book when I had issued the dmi. Had I referenced the book; I would have noted the prerequisites. To prevent repeating this or similar mistakes I will always review the MEL manual and deferred item listing for the aircraft affected; and not rely solely on memory. In addition; the MEL is currently being revised. The dispatch deviation procedure guide will include steps to instruct the mechanic to check; prior to deactivating a thrust reverser the aircraft logbook for deferrals against spoiler and antiskid system; which are not permitted to be deferred in combination. This additional information will serve to remind the technical center and maintenance personnel of the above referenced requirements that must be met to deactivate a thrust reverser.

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Original NASA ASRS Text

Title: A B747-200 WAS DISPATCHED WITH THE #3 THRUST REVERSER INOP PER THE MEL. THE MAINT CTLR FAILED TO NOTE THE AUTOSPOILERS WERE ALSO INOP. THE AUTOSPOILERS MUST BE OPERATIVE WITH AN INOP THRUST REVERSER.

Narrative: ON FEB/FRI/06; WHILE WORKING IN THE CTR; I ISSUED AND ASSIGNED TO FIELD PERSONNEL AN MEL TO PERMIT DEFERRAL OF MAINT ON #3 ENG THRUST REVERSER. REVIEW OF THE ACFT LOGBOOK DURING PREFLT AT THE NEXT STATION REVEALED THAT THE AUTOSPOILERS HAD BEEN PREVIOUSLY DEFERRED ON FEB/TUE/06. MEL PERMITS THRUST REVERSER DEFERRAL; PROVIDED THE AUTOSPOILER SYS OPERATES NORMALLY. EVEN THOUGH NOT INTENTIONAL; I FAILED TO MEET THE REQUIREMENTS OF THE MEL IN ASSURING THAT THE AUTOSPOILERS WERE OPERATING NORMALLY PRIOR TO ASSIGNING THIS DEFERRED MAINT ITEM. THIS WAS DISCOVERED BY FLT CREW PERSONNEL AND RPTED TO THE AIRLINE TECHNICAL CTR. THE TECHNICAL CTR REPRESENTATIVE ON DUTY CONTACTED AND WORKED WITH LINE MAINT PERSONNEL TO REPAIR THE AUTOSPOILERS PRIOR TO THE ACFT BEING RELEASED INTO SVC. CONTRIBUTING TO THIS ERROR WAS THE FAILURE ON MY PART TO THOROUGHLY REVIEW THE DEFERRED MAINT LISTING FOR THE ACFT AFFECTED. THE MEL CLRLY STATES WHAT CONDITIONS THAT MUST BE MET IN ORDER TO DEACTIVATE A THRUST REVERSER. I RELIED ON MEMORY TO DETERMINE THE APPROPRIATE MEL REF AND DID NOT REFER TO THE MEL BOOK WHEN I HAD ISSUED THE DMI. HAD I REFED THE BOOK; I WOULD HAVE NOTED THE PREREQUISITES. TO PREVENT REPEATING THIS OR SIMILAR MISTAKES I WILL ALWAYS REVIEW THE MEL MANUAL AND DEFERRED ITEM LISTING FOR THE ACFT AFFECTED; AND NOT RELY SOLELY ON MEMORY. IN ADDITION; THE MEL IS CURRENTLY BEING REVISED. THE DISPATCH DEV PROC GUIDE WILL INCLUDE STEPS TO INSTRUCT THE MECH TO CHK; PRIOR TO DEACTIVATING A THRUST REVERSER THE ACFT LOGBOOK FOR DEFERRALS AGAINST SPOILER AND ANTISKID SYS; WHICH ARE NOT PERMITTED TO BE DEFERRED IN COMBINATION. THIS ADDITIONAL INFO WILL SERVE TO REMIND THE TECHNICAL CTR AND MAINT PERSONNEL OF THE ABOVE REFED REQUIREMENTS THAT MUST BE MET TO DEACTIVATE A THRUST REVERSER.

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.