Narrative:

We decided to return to einn after discovering a liquid on top of left wing while trying to diagnose a possible fuel indication problem. We turned 90 degrees to our track until 30 NM off track and descended 1000 ft before turning the other 90 degrees towards einn. All procedures were followed and return clearance received from shanwick. Return uneventful. On the ground the liquid on the wing was determined to be deicing fluid (the aircraft had been deiced prior to departing). I think more information needs to be released to all air crews about how deicing fluid can be liquid after 2 hours plus at a cruise altitude of 35000 ft supplemental information from acn 199956: a diversion procedure was initiated following special procedures for in-flight contingencies. A descent to FL340 from FL350 was made in the interests of safety. No conflicts occurred. Callback conversation with reporter revealed the following information: callback made to captain of flight. Captain stated that passenger were nervous over the fluid appearing on the left (port-sun side) wing. They were apprehensive as well, as they had been checking an imbal fuel situation that appeared to be getting worse, indicating as a fuel leak. The imbal was about 4500 to 5000 pounds of fuel from the port wing. The fuel remaining can be checked 2 different ways, either by the totalizer or using the fuel flow against the fuel load for fuel left on board. Either way, the onboard computer prompts the system when a discrepancy of over 3000 pounds exists. A revised clearance was requested and after about 20- 30 mins the aircraft had not received a reclrnc. Neither the flight crew nor shanwick radio had mentioned the word 'emergency.' captain elected to use his emergency command authority for the altitude/heading/track deviation and after establishing contact with shanwick, received 3 revisions of flight plans after the first one. After arriving in shannon the aircraft had its tanks dripped and they found no discrepancy in fuel load. The fuel computers were bite checked, reset and the aircraft refueled for departure. The aircraft had departed the milan airport where it had been deiced. Reporter found out that 2 other incidents relating to deicing fluid being visible on the sun side wing had occurred, causing those 2 wide body 4 enged aircraft to return as a precautionary diversion. This has occurred only out of milan. Reporter showed some irritation that this information was not passed around through company channels. An interesting point noted during this callback was that the captain did not seem overly concerned about the fact that he had not officially declared an emergency with shanwick. Nothing was mentioned later on the return to shannon and no agency has come forth with any questions or proposed action.

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Original NASA ASRS Text

Title: ALTDEV ALT EXCURSION BY ACR WDB ON AN EXTENDED OVERWATER OP. HDG TRACK POS DEV PERFORMED AS ACFT REVERSES COURSE FOR A RETURN LAND ON A DIVERSION TO ALTERNATE ARPT. ACFT INCIDENT STARTED WHEN DEICING FLUID SEEN ON PORT WING AND WAS MISTAKEN FOR FUEL LEAK. THIS COINCIDED WITH AN ACFT FUEL EQUIP PROBLEM.

Narrative: WE DECIDED TO RETURN TO EINN AFTER DISCOVERING A LIQUID ON TOP OF L WING WHILE TRYING TO DIAGNOSE A POSSIBLE FUEL INDICATION PROBLEM. WE TURNED 90 DEGS TO OUR TRACK UNTIL 30 NM OFF TRACK AND DSNDED 1000 FT BEFORE TURNING THE OTHER 90 DEGS TOWARDS EINN. ALL PROCS WERE FOLLOWED AND RETURN CLRNC RECEIVED FROM SHANWICK. RETURN UNEVENTFUL. ON THE GND THE LIQUID ON THE WING WAS DETERMINED TO BE DEICING FLUID (THE ACFT HAD BEEN DEICED PRIOR TO DEPARTING). I THINK MORE INFO NEEDS TO BE RELEASED TO ALL AIR CREWS ABOUT HOW DEICING FLUID CAN BE LIQUID AFTER 2 HRS PLUS AT A CRUISE ALT OF 35000 FT SUPPLEMENTAL INFO FROM ACN 199956: A DIVERSION PROC WAS INITIATED FOLLOWING SPECIAL PROCS FOR INFLT CONTINGENCIES. A DSCNT TO FL340 FROM FL350 WAS MADE IN THE INTERESTS OF SAFETY. NO CONFLICTS OCCURRED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: CALLBACK MADE TO CAPT OF FLT. CAPT STATED THAT PAX WERE NERVOUS OVER THE FLUID APPEARING ON THE L (PORT-SUN SIDE) WING. THEY WERE APPREHENSIVE AS WELL, AS THEY HAD BEEN CHKING AN IMBAL FUEL SITUATION THAT APPEARED TO BE GETTING WORSE, INDICATING AS A FUEL LEAK. THE IMBAL WAS ABOUT 4500 TO 5000 POUNDS OF FUEL FROM THE PORT WING. THE FUEL REMAINING CAN BE CHKED 2 DIFFERENT WAYS, EITHER BY THE TOTALIZER OR USING THE FUEL FLOW AGAINST THE FUEL LOAD FOR FUEL LEFT ON BOARD. EITHER WAY, THE ONBOARD COMPUTER PROMPTS THE SYS WHEN A DISCREPANCY OF OVER 3000 POUNDS EXISTS. A REVISED CLRNC WAS REQUESTED AND AFTER ABOUT 20- 30 MINS THE ACFT HAD NOT RECEIVED A RECLRNC. NEITHER THE FLC NOR SHANWICK RADIO HAD MENTIONED THE WORD 'EMER.' CAPT ELECTED TO USE HIS EMER COMMAND AUTHORITY FOR THE ALT/HDG/TRACK DEV AND AFTER ESTABLISHING CONTACT WITH SHANWICK, RECEIVED 3 REVISIONS OF FLT PLANS AFTER THE FIRST ONE. AFTER ARRIVING IN SHANNON THE ACFT HAD ITS TANKS DRIPPED AND THEY FOUND NO DISCREPANCY IN FUEL LOAD. THE FUEL COMPUTERS WERE BITE CHKED, RESET AND THE ACFT REFUELED FOR DEP. THE ACFT HAD DEPARTED THE MILAN ARPT WHERE IT HAD BEEN DEICED. RPTR FOUND OUT THAT 2 OTHER INCIDENTS RELATING TO DEICING FLUID BEING VISIBLE ON THE SUN SIDE WING HAD OCCURRED, CAUSING THOSE 2 WIDE BODY 4 ENGED ACFT TO RETURN AS A PRECAUTIONARY DIVERSION. THIS HAS OCCURRED ONLY OUT OF MILAN. RPTR SHOWED SOME IRRITATION THAT THIS INFO WAS NOT PASSED AROUND THROUGH COMPANY CHANNELS. AN INTERESTING POINT NOTED DURING THIS CALLBACK WAS THAT THE CAPT DID NOT SEEM OVERLY CONCERNED ABOUT THE FACT THAT HE HAD NOT OFFICIALLY DECLARED AN EMER WITH SHANWICK. NOTHING WAS MENTIONED LATER ON THE RETURN TO SHANNON AND NO AGENCY HAS COME FORTH WITH ANY QUESTIONS OR PROPOSED ACTION.

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