Narrative:

Experience of system and the maintenance personnel's conclusions led us to believe we did the common sense thing to get the aircraft into service. Not understanding the 2 conflicting MEL's. Both MEL's should not have been placed on the aircraft together. On aug/xa/07; I reported for duty on aircraft X for the day's flts. Upon checking into the flight deck; the MEL and maintenance log were missing and 2 maintenance personnel were troubleshooting an MEL. I continued with my receiving aircraft cockpit preparation duties. During my walkaround; I noticed 1 maintenance person working on the cargo door switches. After returning to the cockpit; I asked the other maintenance person what the trouble was and I was informed they were trying to solve a continuously running yellow hydraulic electric pump problem that was traced to the cargo door switches. Before engine start; the captain and I ran the flight deck check for MEL 'Y system lo pr' which called for checking the blue hydraulic electric pump automatic; blue pump override on; yellow electric pump on; check hydraulic pressures on all 3 system (ok) and check for proper flight control spoilers on the ECAM F/control page (ok). Turned off blue hydraulic pump automatic switch to off; then on; this causes the blue override to turn off. Turned off yellow hydraulic electric pump. Complied with MEL with maintenance log notations. We did this check for all 3 flts of the day. However; upon notification by my captain on aug/xa/07; he reported that we may not have operated the aircraft properly according to the second MEL on aircraft X; MEL 'yellow system electric pump inoperative.' per the MEL the yellow hydraulic pump was to be in the off position. With this MEL in place; there is some confusion whether we could actually comply with the previously issued MEL due to the flight deck check of hydraulic system and spoilers because we were not to turn on the yellow hydraulic electric pump. However; circuit breaker T12 was collared per MEL and the yellow hydraulic pump operations were noted normal. After the maintenance discussion about the cause of the continuously running yellow hydraulic pump and their disclosure of tracing it to the cargo door switches; and with our knowledge of the cargo door system and yellow hydraulic interface; we proceeded with the flts and complied with the MEL checks. On the ground; we personally saw the maintenance personnel reset circuit breaker T12 cargo doors and the yellow hydraulic electric pump ran. When they pulled circuit breaker T12 out; the yellow hydraulic electric pump shut off. They also ran the yellow hydraulic electric pump from the overhead switch to allow the ground personnel to close the cargo doors without using the yellow hydraulic hand pump. When they turned off the switch; the yellow hydraulic electric pump turned off. In the future; a closer check on both our parts will be required to find the discrepancies between similar MEL's. In my opinion; these 2 MEL's should not be allowed on an aircraft at the same time due to the potential for conflicting logic. Starting the next day's duty day; captain informed me that he received a call from someone that we may not have understood the MEL's correctly. Make sure maintenance understands the consequences of applying multiple MEL's for similar malfunctions and they are logical. If not; apply 1 and fix the other. I will be more diligent in reviewing every word and note written in the MEL when reviewing for operations; especially when looking at multiple MEL's and how they may interact. Callback conversation with reporter revealed the following information: reporter stated the 'yellow' hydraulic system electric pump was working and not made inoperative. The pulled C/B was for the cargo door switches not the pump. Of the two MEL deferrals; one required verification of yellow system hydraulic press and the yellow electric pump to be operational; while the other MEL required the yellow electric pump to be deferred as inoperative. They departed with the yellow pump fully operational even though the MEL deferral said pump was inoperative.

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Original NASA ASRS Text

Title: AN AIRBUS A319 ACFT RELEASED FOR SERVICE WITH CONFLICTING MAINT MEL'S. FLIGHT CREW AND MAINT NOT ALERT TO THE REQUIREMENT ONE MEL HAD OVER THE OTHER.

Narrative: EXPERIENCE OF SYS AND THE MAINT PERSONNEL'S CONCLUSIONS LED US TO BELIEVE WE DID THE COMMON SENSE THING TO GET THE ACFT INTO SVC. NOT UNDERSTANDING THE 2 CONFLICTING MEL'S. BOTH MEL'S SHOULD NOT HAVE BEEN PLACED ON THE ACFT TOGETHER. ON AUG/XA/07; I RPTED FOR DUTY ON ACFT X FOR THE DAY'S FLTS. UPON CHKING INTO THE FLT DECK; THE MEL AND MAINT LOG WERE MISSING AND 2 MAINT PERSONNEL WERE TROUBLESHOOTING AN MEL. I CONTINUED WITH MY RECEIVING ACFT COCKPIT PREPARATION DUTIES. DURING MY WALKAROUND; I NOTICED 1 MAINT PERSON WORKING ON THE CARGO DOOR SWITCHES. AFTER RETURNING TO THE COCKPIT; I ASKED THE OTHER MAINT PERSON WHAT THE TROUBLE WAS AND I WAS INFORMED THEY WERE TRYING TO SOLVE A CONTINUOUSLY RUNNING YELLOW HYD ELECTRIC PUMP PROB THAT WAS TRACED TO THE CARGO DOOR SWITCHES. BEFORE ENG START; THE CAPT AND I RAN THE FLT DECK CHK FOR MEL 'Y SYS LO PR' WHICH CALLED FOR CHKING THE BLUE HYD ELECTRIC PUMP AUTO; BLUE PUMP OVERRIDE ON; YELLOW ELECTRIC PUMP ON; CHK HYD PRESSURES ON ALL 3 SYS (OK) AND CHK FOR PROPER FLT CTL SPOILERS ON THE ECAM F/CTL PAGE (OK). TURNED OFF BLUE HYD PUMP AUTO SWITCH TO OFF; THEN ON; THIS CAUSES THE BLUE OVERRIDE TO TURN OFF. TURNED OFF YELLOW HYD ELECTRIC PUMP. COMPLIED WITH MEL WITH MAINT LOG NOTATIONS. WE DID THIS CHK FOR ALL 3 FLTS OF THE DAY. HOWEVER; UPON NOTIFICATION BY MY CAPT ON AUG/XA/07; HE RPTED THAT WE MAY NOT HAVE OPERATED THE ACFT PROPERLY ACCORDING TO THE SECOND MEL ON ACFT X; MEL 'YELLOW SYS ELECTRIC PUMP INOP.' PER THE MEL THE YELLOW HYD PUMP WAS TO BE IN THE OFF POS. WITH THIS MEL IN PLACE; THERE IS SOME CONFUSION WHETHER WE COULD ACTUALLY COMPLY WITH THE PREVIOUSLY ISSUED MEL DUE TO THE FLT DECK CHK OF HYD SYS AND SPOILERS BECAUSE WE WERE NOT TO TURN ON THE YELLOW HYD ELECTRIC PUMP. HOWEVER; CIRCUIT BREAKER T12 WAS COLLARED PER MEL AND THE YELLOW HYD PUMP OPS WERE NOTED NORMAL. AFTER THE MAINT DISCUSSION ABOUT THE CAUSE OF THE CONTINUOUSLY RUNNING YELLOW HYD PUMP AND THEIR DISCLOSURE OF TRACING IT TO THE CARGO DOOR SWITCHES; AND WITH OUR KNOWLEDGE OF THE CARGO DOOR SYS AND YELLOW HYD INTERFACE; WE PROCEEDED WITH THE FLTS AND COMPLIED WITH THE MEL CHKS. ON THE GND; WE PERSONALLY SAW THE MAINT PERSONNEL RESET CIRCUIT BREAKER T12 CARGO DOORS AND THE YELLOW HYD ELECTRIC PUMP RAN. WHEN THEY PULLED CIRCUIT BREAKER T12 OUT; THE YELLOW HYD ELECTRIC PUMP SHUT OFF. THEY ALSO RAN THE YELLOW HYD ELECTRIC PUMP FROM THE OVERHEAD SWITCH TO ALLOW THE GND PERSONNEL TO CLOSE THE CARGO DOORS WITHOUT USING THE YELLOW HYD HAND PUMP. WHEN THEY TURNED OFF THE SWITCH; THE YELLOW HYD ELECTRIC PUMP TURNED OFF. IN THE FUTURE; A CLOSER CHK ON BOTH OUR PARTS WILL BE REQUIRED TO FIND THE DISCREPANCIES BTWN SIMILAR MEL'S. IN MY OPINION; THESE 2 MEL'S SHOULD NOT BE ALLOWED ON AN ACFT AT THE SAME TIME DUE TO THE POTENTIAL FOR CONFLICTING LOGIC. STARTING THE NEXT DAY'S DUTY DAY; CAPT INFORMED ME THAT HE RECEIVED A CALL FROM SOMEONE THAT WE MAY NOT HAVE UNDERSTOOD THE MEL'S CORRECTLY. MAKE SURE MAINT UNDERSTANDS THE CONSEQUENCES OF APPLYING MULTIPLE MEL'S FOR SIMILAR MALFUNCTIONS AND THEY ARE LOGICAL. IF NOT; APPLY 1 AND FIX THE OTHER. I WILL BE MORE DILIGENT IN REVIEWING EVERY WORD AND NOTE WRITTEN IN THE MEL WHEN REVIEWING FOR OPS; ESPECIALLY WHEN LOOKING AT MULTIPLE MEL'S AND HOW THEY MAY INTERACT. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: RPTR STATED THE 'YELLOW' HYD SYSTEM ELECTRIC PUMP WAS WORKING AND NOT MADE INOP. THE PULLED C/B WAS FOR THE CARGO DOOR SWITCHES NOT THE PUMP. OF THE TWO MEL DEFERRALS; ONE REQUIRED VERIFICATION OF YELLOW SYS HYD PRESS AND THE YELLOW ELECTRIC PUMP TO BE OPERATIONAL; WHILE THE OTHER MEL REQUIRED THE YELLOW ELECTRIC PUMP TO BE DEFERRED AS INOP. THEY DEPARTED WITH THE YELLOW PUMP FULLY OPERATIONAL EVEN THOUGH THE MEL DEFERRAL SAID PUMP WAS INOP.

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.