Narrative:

MEL's in potential conflict and subject to interpretation. I chose to operate a flight that had the EPR probe heat of one engine inoperative; the related EPR indication inoperative; and the autothrottle system inoperative. Attached is the chain of events and human performance considerations along with recommendations to correct the situation and recurrence. There exists a possible conflict in MEL's which may lead to either 1) an aircraft grounded when it is actually legal and safe to dispatch; or 2) an aircraft being dispatched illegally. I reviewed the aircraft readiness document online the day before my flight and called to alert operations that this aircraft will not be legal to fly into foreign airspace with the present MEL's. Arrived the hub to find aircraft had 6 MEL's. One of which was incorrect; showing the inner fuel tank pump fault 'light' as inoperative instead of the pump itself. My first officer and I reviewed the other MEL's and interpreted the EPR system as being legal for dispatch provided the entire flight was conducted with ats lever off. Thus; more restrictive rather than in conflict with each other. Maintenance control and the ramp mechanics agreed as did the previous crews who had flown the jet. Arrived aircraft and discussed the pump light fault versus pump fault with mechanic and he agreed to change the logbook. However; it required a new flight plan calculated at an FL200 fuel burn and an additional 4400 pounds in each inner as 'unusable.' I then asked the fueler to stay here as we would need more fuel. Reviewing the EPR MEL's; maintenance said they had been working on MEL 77-10-01-B EPR #1 and #2 indications inoperative. I asked them why it was not signed off since the indicators were indeed working. They said they were not sure if it might fault later on in-flight due to the EPR probe heat fault affects the associated EPR system and its gauge. I made mention of the note from maintenance control that if they would fix the EPR probe heat fault; that the other problems would go away. They assured me that the jet was flight ready and legal. Additionally; several other crews agreed and had just flown it in bringing it to me. We agreed; as a crew; that it was not a conflicting MEL but rather one that required a more conservative operation with manual throttle procedures. All other requirements were met and accounted for in planning; and the takeoff; en route; and approach phases of flight. Both my first officer and I treated the MEL's in the more restrictive manner and thus took the aircraft without the use of the ats for the duration of the flight. Especially; as it was not expressed in the main box to the right of the MEL labeled as '(M)' '(O)' as a requirement to have the ats lever on. But rather just discussed in the latter paragraph as an operational procedure to turn the ats lever on; but rather to use manual autothrottle procedures and the availability to use profile above 3000 ft after gear retraction. Recommendations: if the MEL's ae in conflict rendering the aircraft grounded until repaired; it would be helpful to add the requirement of the ats lever 'on' to be listed in the main box of remarks or exceptions. Also; it could and should indicate that no operational relief is given for the other related MEL's. If these MEL's are not really in conflict and the aircraft is considered legal to dispatch; then the note to turn the ATIS lever 'on' should be amended with wording such as 'if available;' and additionally that relief is offered for the related system. Safety would best be served if maintenance control has a 'relational database' incorporated into our computer generated release and flight planning system; that would prohibit the issuance of a release/flight plan with 'conflicting' MEL's and; therefore; not airworthy. The system that generates both the aircraft release and fpr would thus serve as a final xchk to ensure that no conflicting MEL's could be printed on the same fpr and potentially releasing an aircraft that is indeed not airworthy. Other factors that raise warning signs are the unnecessary interruptions to legal crew rest; dealing with an excessive number of MEL's; especially if they are in conflict with each other and the reliance one might placeon the advice of maintenance staff that is signing off on the aircraft.

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Original NASA ASRS Text

Title: AN A310 CREW FLEW AN ACFT WITH CONFLICTING MEL ITEMS PRESENTING UNCLR SYS REQUIREMENTS AND CONFUSING THE LEGALITY OF ACFT READINESS.

Narrative: MEL'S IN POTENTIAL CONFLICT AND SUBJECT TO INTERP. I CHOSE TO OPERATE A FLT THAT HAD THE EPR PROBE HEAT OF ONE ENG INOP; THE RELATED EPR INDICATION INOP; AND THE AUTOTHROTTLE SYS INOP. ATTACHED IS THE CHAIN OF EVENTS AND HUMAN PERFORMANCE CONSIDERATIONS ALONG WITH RECOMMENDATIONS TO CORRECT THE SIT AND RECURRENCE. THERE EXISTS A POSSIBLE CONFLICT IN MEL'S WHICH MAY LEAD TO EITHER 1) AN ACFT GNDED WHEN IT IS ACTUALLY LEGAL AND SAFE TO DISPATCH; OR 2) AN ACFT BEING DISPATCHED ILLEGALLY. I REVIEWED THE ACFT READINESS DOCUMENT ONLINE THE DAY BEFORE MY FLT AND CALLED TO ALERT OPS THAT THIS ACFT WILL NOT BE LEGAL TO FLY INTO FOREIGN AIRSPACE WITH THE PRESENT MEL'S. ARRIVED THE HUB TO FIND ACFT HAD 6 MEL'S. ONE OF WHICH WAS INCORRECT; SHOWING THE INNER FUEL TANK PUMP FAULT 'LIGHT' AS INOP INSTEAD OF THE PUMP ITSELF. MY FO AND I REVIEWED THE OTHER MEL'S AND INTERPED THE EPR SYS AS BEING LEGAL FOR DISPATCH PROVIDED THE ENTIRE FLT WAS CONDUCTED WITH ATS LEVER OFF. THUS; MORE RESTRICTIVE RATHER THAN IN CONFLICT WITH EACH OTHER. MAINT CTL AND THE RAMP MECHS AGREED AS DID THE PREVIOUS CREWS WHO HAD FLOWN THE JET. ARRIVED ACFT AND DISCUSSED THE PUMP LIGHT FAULT VERSUS PUMP FAULT WITH MECH AND HE AGREED TO CHANGE THE LOGBOOK. HOWEVER; IT REQUIRED A NEW FLT PLAN CALCULATED AT AN FL200 FUEL BURN AND AN ADDITIONAL 4400 LBS IN EACH INNER AS 'UNUSABLE.' I THEN ASKED THE FUELER TO STAY HERE AS WE WOULD NEED MORE FUEL. REVIEWING THE EPR MEL'S; MAINT SAID THEY HAD BEEN WORKING ON MEL 77-10-01-B EPR #1 AND #2 INDICATIONS INOP. I ASKED THEM WHY IT WAS NOT SIGNED OFF SINCE THE INDICATORS WERE INDEED WORKING. THEY SAID THEY WERE NOT SURE IF IT MIGHT FAULT LATER ON INFLT DUE TO THE EPR PROBE HEAT FAULT AFFECTS THE ASSOCIATED EPR SYS AND ITS GAUGE. I MADE MENTION OF THE NOTE FROM MAINT CTL THAT IF THEY WOULD FIX THE EPR PROBE HEAT FAULT; THAT THE OTHER PROBS WOULD GO AWAY. THEY ASSURED ME THAT THE JET WAS FLT READY AND LEGAL. ADDITIONALLY; SEVERAL OTHER CREWS AGREED AND HAD JUST FLOWN IT IN BRINGING IT TO ME. WE AGREED; AS A CREW; THAT IT WAS NOT A CONFLICTING MEL BUT RATHER ONE THAT REQUIRED A MORE CONSERVATIVE OP WITH MANUAL THROTTLE PROCS. ALL OTHER REQUIREMENTS WERE MET AND ACCOUNTED FOR IN PLANNING; AND THE TKOF; ENRTE; AND APCH PHASES OF FLT. BOTH MY FO AND I TREATED THE MEL'S IN THE MORE RESTRICTIVE MANNER AND THUS TOOK THE ACFT WITHOUT THE USE OF THE ATS FOR THE DURATION OF THE FLT. ESPECIALLY; AS IT WAS NOT EXPRESSED IN THE MAIN BOX TO THE R OF THE MEL LABELED AS '(M)' '(O)' AS A REQUIREMENT TO HAVE THE ATS LEVER ON. BUT RATHER JUST DISCUSSED IN THE LATTER PARAGRAPH AS AN OPERATIONAL PROC TO TURN THE ATS LEVER ON; BUT RATHER TO USE MANUAL AUTOTHROTTLE PROCS AND THE AVAILABILITY TO USE PROFILE ABOVE 3000 FT AFTER GEAR RETRACTION. RECOMMENDATIONS: IF THE MEL'S AE IN CONFLICT RENDERING THE ACFT GNDED UNTIL REPAIRED; IT WOULD BE HELPFUL TO ADD THE REQUIREMENT OF THE ATS LEVER 'ON' TO BE LISTED IN THE MAIN BOX OF REMARKS OR EXCEPTIONS. ALSO; IT COULD AND SHOULD INDICATE THAT NO OPERATIONAL RELIEF IS GIVEN FOR THE OTHER RELATED MEL'S. IF THESE MEL'S ARE NOT REALLY IN CONFLICT AND THE ACFT IS CONSIDERED LEGAL TO DISPATCH; THEN THE NOTE TO TURN THE ATIS LEVER 'ON' SHOULD BE AMENDED WITH WORDING SUCH AS 'IF AVAILABLE;' AND ADDITIONALLY THAT RELIEF IS OFFERED FOR THE RELATED SYS. SAFETY WOULD BEST BE SERVED IF MAINT CTL HAS A 'RELATIONAL DATABASE' INCORPORATED INTO OUR COMPUTER GENERATED RELEASE AND FLT PLANNING SYS; THAT WOULD PROHIBIT THE ISSUANCE OF A RELEASE/FLT PLAN WITH 'CONFLICTING' MEL'S AND; THEREFORE; NOT AIRWORTHY. THE SYS THAT GENERATES BOTH THE ACFT RELEASE AND FPR WOULD THUS SERVE AS A FINAL XCHK TO ENSURE THAT NO CONFLICTING MEL'S COULD BE PRINTED ON THE SAME FPR AND POTENTIALLY RELEASING AN ACFT THAT IS INDEED NOT AIRWORTHY. OTHER FACTORS THAT RAISE WARNING SIGNS ARE THE UNNECESSARY INTERRUPTIONS TO LEGAL CREW REST; DEALING WITH AN EXCESSIVE NUMBER OF MEL'S; ESPECIALLY IF THEY ARE IN CONFLICT WITH EACH OTHER AND THE RELIANCE ONE MIGHT PLACEON THE ADVICE OF MAINT STAFF THAT IS SIGNING OFF ON THE ACFT.

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.