Narrative:

I was in the right seat working the radios during a reposition taxi of aircraft from the terminal to the maintenance hangar. During taxi we experienced an engine egt exceedance and shutdown of #2 engine. We were alerted to the problem by a chime at which time we both looked at the instruments and noticed the right engine oil pressure going down and the egt over 900 degrees C. The right engine fuel lever was immediately cut off by the mechanic in the left seat. After shutdown we motored the engine until the egt was below 200 degree. This occurred with both engines at idle and taxing at normal speed. The last time the engines were advanced above idle was to cross runway xx. The taxi down taxiway alpha was approximately 1/2 mile so the engines were at idle for several minutes when the over temperature occurred. The outside air temperature was in the 50's and wind was negligible. I have no explanation for the cause of this incident and know of no way we could have prevented it unless one of us were looking at the instruments at the exact moment the engine started to over temperature. There have been several instances of over temperatures during taxi on 757's at air carrier X with a lot of speculation as to the cause. I feel what is needed is an earlier aural alert to any engine parameter exceedances (especially egt) during ground operation; without which the probability of a reoccurrence is high.callback conversation with reporter revealed the following information: reporter stated this was not the first time his carrier has had unexplained high egt readings on their RB211-535 engines that suddenly appear without any prior warning. Reporter stated he personally knows of three other incidents where very competent taxi crew mechanics have experienced the same conditions of sudden high engine egt during idle taxi. Most of the time the event happens shortly after engines are advanced above idle when moving the aircraft across a runway and the RB211's are throttled back to idle. But his high egt event happened several minutes after they had throttled back to idle. Approximately two years ago; taxi and engine run mechanics were briefed to be more diligent on the engine instruments and indications. He questions if the pilots have the same problem; or if procedures are different when they are taxiing. Reporter stated there is a software upgrade program available to give progressive and earlier warnings of an engine egt rise; but his carrier does not want to spend the money. He does not know whether boeing or the engine manufacturer; rolls royce; offers the program. The #2 engine required removal after the sudden high egt exceedance rise above 900 degrees centigrade. Reporter also stated no one from his company engineering has come down to talk with the taxi and engine run-up crews to get their input regarding the high egt events. The same #2 engine had been scheduled to come off the B757-200 one week earlier.

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Original NASA ASRS Text

Title: DURING A REPOSITION TAXI OF A B757-200; TWO MECHANICS WERE ALERTED BY A CHIME AND NOTICED THE RIGHT ENGINE OIL PRESSURE DROPPING AND AN EGT EXCEEDANCE OVER 900 DEGREES CENTIGRADE; REQUIRING THE #2 ENGINE TO BE SHUT DOWN.

Narrative: I WAS IN THE RIGHT SEAT WORKING THE RADIOS DURING A REPOSITION TAXI OF ACFT FROM THE TERMINAL TO THE MAINT HANGAR. DURING TAXI WE EXPERIENCED AN ENGINE EGT EXCEEDANCE AND SHUTDOWN OF #2 ENGINE. WE WERE ALERTED TO THE PROBLEM BY A CHIME AT WHICH TIME WE BOTH LOOKED AT THE INSTRUMENTS AND NOTICED THE R ENGINE OIL PRESSURE GOING DOWN AND THE EGT OVER 900 DEGS C. THE R ENGINE FUEL LEVER WAS IMMEDIATELY CUT OFF BY THE MECHANIC IN THE LEFT SEAT. AFTER SHUTDOWN WE MOTORED THE ENGINE UNTIL THE EGT WAS BELOW 200 DEG. THIS OCCURRED WITH BOTH ENGINES AT IDLE AND TAXING AT NORMAL SPEED. THE LAST TIME THE ENGINES WERE ADVANCED ABOVE IDLE WAS TO CROSS RUNWAY XX. THE TAXI DOWN TAXIWAY ALPHA WAS APPROXIMATELY 1/2 MILE SO THE ENGINES WERE AT IDLE FOR SEVERAL MINUTES WHEN THE OVER TEMP OCCURRED. THE OUTSIDE AIR TEMPERATURE WAS IN THE 50'S AND WIND WAS NEGLIGIBLE. I HAVE NO EXPLANATION FOR THE CAUSE OF THIS INCIDENT AND KNOW OF NO WAY WE COULD HAVE PREVENTED IT UNLESS ONE OF US WERE LOOKING AT THE INSTRUMENTS AT THE EXACT MOMENT THE ENGINE STARTED TO OVER TEMP. THERE HAVE BEEN SEVERAL INSTANCES OF OVER TEMPS DURING TAXI ON 757'S AT ACR X WITH A LOT OF SPECULATION AS TO THE CAUSE. I FEEL WHAT IS NEEDED IS AN EARLIER AURAL ALERT TO ANY ENGINE PARAMETER EXCEEDANCES (ESPECIALLY EGT) DURING GROUND OPERATION; WITHOUT WHICH THE PROBABILITY OF A REOCCURRENCE IS HIGH.CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: REPORTER STATED THIS WAS NOT THE FIRST TIME HIS CARRIER HAS HAD UNEXPLAINED HIGH EGT READINGS ON THEIR RB211-535 ENGINES THAT SUDDENLY APPEAR WITHOUT ANY PRIOR WARNING. REPORTER STATED HE PERSONALLY KNOWS OF THREE OTHER INCIDENTS WHERE VERY COMPETENT TAXI CREW MECHANICS HAVE EXPERIENCED THE SAME CONDITIONS OF SUDDEN HIGH ENGINE EGT DURING IDLE TAXI. MOST OF THE TIME THE EVENT HAPPENS SHORTLY AFTER ENGINES ARE ADVANCED ABOVE IDLE WHEN MOVING THE AIRCRAFT ACROSS A RUNWAY AND THE RB211'S ARE THROTTLED BACK TO IDLE. BUT HIS HIGH EGT EVENT HAPPENED SEVERAL MINUTES AFTER THEY HAD THROTTLED BACK TO IDLE. APPROXIMATELY TWO YEARS AGO; TAXI AND ENGINE RUN MECHANICS WERE BRIEFED TO BE MORE DILIGENT ON THE ENGINE INSTRUMENTS AND INDICATIONS. HE QUESTIONS IF THE PILOTS HAVE THE SAME PROBLEM; OR IF PROCEDURES ARE DIFFERENT WHEN THEY ARE TAXIING. REPORTER STATED THERE IS A SOFTWARE UPGRADE PROGRAM AVAILABLE TO GIVE PROGRESSIVE AND EARLIER WARNINGS OF AN ENGINE EGT RISE; BUT HIS CARRIER DOES NOT WANT TO SPEND THE MONEY. HE DOES NOT KNOW WHETHER BOEING OR THE ENGINE MANUFACTURER; ROLLS ROYCE; OFFERS THE PROGRAM. THE #2 ENGINE REQUIRED REMOVAL AFTER THE SUDDEN HIGH EGT EXCEEDANCE RISE ABOVE 900 DEGREES CENTIGRADE. REPORTER ALSO STATED NO ONE FROM HIS COMPANY ENGINEERING HAS COME DOWN TO TALK WITH THE TAXI AND ENGINE RUN-UP CREWS TO GET THEIR INPUT REGARDING THE HIGH EGT EVENTS. THE SAME #2 ENGINE HAD BEEN SCHEDULED TO COME OFF THE B757-200 ONE WEEK EARLIER.

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