Narrative:

In attempting to operate a widebody transport flight out of ord in feb, a series of very complicated and involved operational issues surfaced which caused extensive delay and near cancellation of our flight. These issues principally involved MEL items and inoperative components with regard to operations into icing conditions. Of major concern was the difficulty of interpreting the MEL to determine if the operation was permissible. This was further complicated by conflicting MEL directives as contained in computer storage that engineering has access to versus information that maintenance provided via its maintenance release document. The step by step resolution of this problem by the flight crew, maintenance dispatcher was undertaken, and what appeared to be problem that would be resolved momentarily continued and became more complicated and time consuming. These were the factors, information and pr provided to an interested audience. The following highlights additional details of concerns and problems regarding this flight. Operations were delayed due to snow and icing conditions at ord. Light snow was falling and the temperature was 26 degrees F. The aircraft was initially deiced some 10-15 mins prior to scheduled departure time. Then passenger service announced a departure delay from the scheduled XA05 to a new time of XA25. As snow continued to fall coupled with this long delay, another deice service was requested. This was accomplished and concluded at XA50 and our flight departed the blocks at XA55. Departure delays were occurring and taxi was slow. Approximately 25 mins after block departure we decided to return to the gate for additional deicing. We were nearing #1 position for takeoff, but snow was still falling and it could not be assured that the wings/control surfaces were free of frost, snow or ice. About this time our dispatcher contacted us regarding some question as to the possibility that flight into known icing conditions may not be appropriate. We had a #1 pneumatic temperature gauge that was inoperative, but operation under MEL authority (see 1 attached) this seemed appropriate so long as the systems supplying pneumatic air for ice protection had operation temperature gauges. However, his point was well taken as further discussion proved that the MEL in this area was far from being clear. Was the system with the inoperative temperature gauge to be turned off if the flight was to be operated into icing conditions? Then what consideration should be given to reduced pneumatic capacity. Should the #1 pneumatic system have been deactivated by maintenance under this situation? At this time engineering was contacted, and when he pulled up the MEL from his computer in san francisco, it indicated that operation into icing conditions was permitted. We were in agreement and I asked that a copy of maintenance release document with the MEL information be sent to me through the computer terminal at the gate and we would be underway. I received the document (see 2 attached) and proceeded to board the aircraft when to my shock I noticed the same restrictions were still part of the document, flight shall not be made into icing conditions. So, back to the gate telephone and another call. In the meantime we patched in the dispatcher and had ord line maintenance in the communications loop. We were all perplexed! I was satisfied that the operation would have been correct and proper as was ordmm and chidd, but I explained that it would be necessary to have correct paperwork to show this as part of the aircraft logbook documentation. This problem took nearly 1 hour to resolve! It was finally decided that maintenance should deactivate the pneumatic system with the inoperative temperature gauge. Thus, a new MEL would come into play (see 3 attached) authorizing operations into icing conditions. This complicated and round-about way to try to operate under an MEL authorization should not exist. Ironically, after takeoff a wing anti-ice valve failed to open. Since we were in icing conditions, we continued climb to a high altitude where we were clear of ice accumulation. Our second officer could not open the valve after several attempts by using the irregular procedures and with the assistance of our dispatcher, we were prepared to fly to a new destination that was freeof icing conditions. However, one last attempt at opening the valve succeeded, and we flew on to our original destination where the aircraft was taken OTS.

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Original NASA ASRS Text

Title: ACR WDB DELAYED BECAUSE OF INOPERATIVE TEMPERATURE GAUGE DUE TO CONFLICTING INTERP BY MAINTENANCE OF MINIMUM EQUIPMENT LIST.

Narrative: IN ATTEMPTING TO OPERATE A WDB FLT OUT OF ORD IN FEB, A SERIES OF VERY COMPLICATED AND INVOLVED OPERATIONAL ISSUES SURFACED WHICH CAUSED EXTENSIVE DELAY AND NEAR CANCELLATION OF OUR FLT. THESE ISSUES PRINCIPALLY INVOLVED MEL ITEMS AND INOP COMPONENTS WITH REGARD TO OPS INTO ICING CONDITIONS. OF MAJOR CONCERN WAS THE DIFFICULTY OF INTERPRETING THE MEL TO DETERMINE IF THE OP WAS PERMISSIBLE. THIS WAS FURTHER COMPLICATED BY CONFLICTING MEL DIRECTIVES AS CONTAINED IN COMPUTER STORAGE THAT ENGINEERING HAS ACCESS TO VERSUS INFO THAT MAINT PROVIDED VIA ITS MAINT RELEASE DOCUMENT. THE STEP BY STEP RESOLUTION OF THIS PROB BY THE FLT CREW, MAINT DISPATCHER WAS UNDERTAKEN, AND WHAT APPEARED TO BE PROB THAT WOULD BE RESOLVED MOMENTARILY CONTINUED AND BECAME MORE COMPLICATED AND TIME CONSUMING. THESE WERE THE FACTORS, INFO AND PR PROVIDED TO AN INTERESTED AUDIENCE. THE FOLLOWING HIGHLIGHTS ADDITIONAL DETAILS OF CONCERNS AND PROBS REGARDING THIS FLT. OPS WERE DELAYED DUE TO SNOW AND ICING CONDITIONS AT ORD. LIGHT SNOW WAS FALLING AND THE TEMP WAS 26 DEGS F. THE ACFT WAS INITIALLY DEICED SOME 10-15 MINS PRIOR TO SCHEDULED DEP TIME. THEN PAX SVC ANNOUNCED A DEP DELAY FROM THE SCHEDULED XA05 TO A NEW TIME OF XA25. AS SNOW CONTINUED TO FALL COUPLED WITH THIS LONG DELAY, ANOTHER DEICE SVC WAS REQUESTED. THIS WAS ACCOMPLISHED AND CONCLUDED AT XA50 AND OUR FLT DEPARTED THE BLOCKS AT XA55. DEP DELAYS WERE OCCURRING AND TAXI WAS SLOW. APPROX 25 MINS AFTER BLOCK DEP WE DECIDED TO RETURN TO THE GATE FOR ADDITIONAL DEICING. WE WERE NEARING #1 POS FOR TKOF, BUT SNOW WAS STILL FALLING AND IT COULD NOT BE ASSURED THAT THE WINGS/CTL SURFACES WERE FREE OF FROST, SNOW OR ICE. ABOUT THIS TIME OUR DISPATCHER CONTACTED US REGARDING SOME QUESTION AS TO THE POSSIBILITY THAT FLT INTO KNOWN ICING CONDITIONS MAY NOT BE APPROPRIATE. WE HAD A #1 PNEUMATIC TEMP GAUGE THAT WAS INOP, BUT OPERATION UNDER MEL AUTHORITY (SEE 1 ATTACHED) THIS SEEMED APPROPRIATE SO LONG AS THE SYSTEMS SUPPLYING PNEUMATIC AIR FOR ICE PROTECTION HAD OP TEMP GAUGES. HOWEVER, HIS POINT WAS WELL TAKEN AS FURTHER DISCUSSION PROVED THAT THE MEL IN THIS AREA WAS FAR FROM BEING CLEAR. WAS THE SYS WITH THE INOP TEMP GAUGE TO BE TURNED OFF IF THE FLT WAS TO BE OPERATED INTO ICING CONDITIONS? THEN WHAT CONSIDERATION SHOULD BE GIVEN TO REDUCED PNEUMATIC CAPACITY. SHOULD THE #1 PNEUMATIC SYS HAVE BEEN DEACTIVATED BY MAINT UNDER THIS SITUATION? AT THIS TIME ENGINEERING WAS CONTACTED, AND WHEN HE PULLED UP THE MEL FROM HIS COMPUTER IN SAN FRANCISCO, IT INDICATED THAT OPERATION INTO ICING CONDITIONS WAS PERMITTED. WE WERE IN AGREEMENT AND I ASKED THAT A COPY OF MAINT RELEASE DOCUMENT WITH THE MEL INFO BE SENT TO ME THROUGH THE COMPUTER TERMINAL AT THE GATE AND WE WOULD BE UNDERWAY. I RECEIVED THE DOCUMENT (SEE 2 ATTACHED) AND PROCEEDED TO BOARD THE ACFT WHEN TO MY SHOCK I NOTICED THE SAME RESTRICTIONS WERE STILL PART OF THE DOCUMENT, FLT SHALL NOT BE MADE INTO ICING CONDITIONS. SO, BACK TO THE GATE TELEPHONE AND ANOTHER CALL. IN THE MEANTIME WE PATCHED IN THE DISPATCHER AND HAD ORD LINE MAINT IN THE COMS LOOP. WE WERE ALL PERPLEXED! I WAS SATISFIED THAT THE OPERATION WOULD HAVE BEEN CORRECT AND PROPER AS WAS ORDMM AND CHIDD, BUT I EXPLAINED THAT IT WOULD BE NECESSARY TO HAVE CORRECT PAPERWORK TO SHOW THIS AS PART OF THE ACFT LOGBOOK DOCUMENTATION. THIS PROB TOOK NEARLY 1 HR TO RESOLVE! IT WAS FINALLY DECIDED THAT MAINT SHOULD DEACTIVATE THE PNEUMATIC SYS WITH THE INOP TEMP GAUGE. THUS, A NEW MEL WOULD COME INTO PLAY (SEE 3 ATTACHED) AUTHORIZING OPS INTO ICING CONDITIONS. THIS COMPLICATED AND ROUND-ABOUT WAY TO TRY TO OPERATE UNDER AN MEL AUTHORIZATION SHOULD NOT EXIST. IRONICALLY, AFTER TKOF A WING ANTI-ICE VALVE FAILED TO OPEN. SINCE WE WERE IN ICING CONDITIONS, WE CONTINUED CLB TO A HIGH ALT WHERE WE WERE CLR OF ICE ACCUMULATION. OUR S/O COULD NOT OPEN THE VALVE AFTER SEVERAL ATTEMPTS BY USING THE IRREGULAR PROCS AND WITH THE ASSISTANCE OF OUR DISPATCHER, WE WERE PREPARED TO FLY TO A NEW DEST THAT WAS FREEOF ICING CONDITIONS. HOWEVER, ONE LAST ATTEMPT AT OPENING THE VALVE SUCCEEDED, AND WE FLEW ON TO OUR ORIGINAL DEST WHERE THE ACFT WAS TAKEN OTS.

Data retrieved from NASA's ASRS site as of August 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.