37000 Feet | Browse and search NASA's Aviation Safety Reporting System |
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Attributes | |
ACN | 421544 |
Time | |
Date | 199811 |
Day | Sun |
Local Time Of Day | 0001 To 0600 |
Place | |
Locale Reference | atc facility : osi |
State Reference | CA |
Altitude | msl bound lower : 36000 msl bound upper : 36000 |
Environment | |
Flight Conditions | VMC |
Light | Night |
Aircraft 1 | |
Controlling Facilities | artcc : zoa |
Operator | common carrier : air carrier |
Make Model Name | DC-10 40 |
Operating Under FAR Part | Part 121 |
Navigation In Use | Other |
Flight Phase | descent other |
Route In Use | enroute : direct enroute : pacific enroute other |
Flight Plan | IFR |
Person 1 | |
Affiliation | company : air carrier |
Function | flight crew : captain oversight : pic |
Qualification | pilot : atp |
Experience | flight time last 90 days : 200 flight time total : 18000 flight time type : 180 |
ASRS Report | 421544 |
Person 2 | |
Affiliation | company : air carrier |
Function | flight crew : first officer |
Qualification | pilot : commercial pilot : instrument |
Events | |
Anomaly | aircraft equipment problem : critical other anomaly other |
Independent Detector | other flight crewa |
Resolutory Action | flight crew : overcame equipment problem other |
Consequence | Other |
Supplementary | |
Primary Problem | Aircraft |
Air Traffic Incident | other |
Narrative:
Upon power reduction on descent from FL360, #3 engine experienced a surge (apparent compressor stall) and the egt started to rise. We shut the engine down, prior to an overheat. We then restarted the engine according to the checklist and it appeared to run normally for the duration of the flight. ATC was not notified as we rectified the problem without having to deviate from any clrncs. The engine appeared to be operating normally. This is reported to be a fairly common problem with the engines on the DC10-40, pratt & whitney. Callback conversation with reporter revealed the following information: the pilot's air carrier has had such a problem with this engine that there is a special throttle closure procedure in the flight manual. Before touching the throttles for descent, the engine thermal anti-ice and fuel heat must be turned on and operated. The extra pneumatic bleed is supposed to increase the engine stall margin. The #2 throttle is then reduced to idle over 10 seconds minimum. After #2 is stabilized, the same procedure is used to retard #1 and #3 throttles. The crew used this procedure this time but it did not prevent a stall and egt runaway. This pilot flew this aircraft several days later and maintenance accomplished the prescribed inspections without finding any problems. The very next flight the item repeated and the air carrier ferried the aircraft to its main maintenance base for an engine change. The pilot has seen this before on both B747's and DC10's. He wondered why, after all this time, that pratt & whitney is incapable of fixing the problem.
Original NASA ASRS Text
Title: DC10 WITH A PRATT & WHITNEY JT9D-20 ENG HAD AN ENG COMPRESSOR STALL AND IMPENDING ENG OVERTEMP, REQUIRING ENG SHUTDOWN.
Narrative: UPON PWR REDUCTION ON DSCNT FROM FL360, #3 ENG EXPERIENCED A SURGE (APPARENT COMPRESSOR STALL) AND THE EGT STARTED TO RISE. WE SHUT THE ENG DOWN, PRIOR TO AN OVERHEAT. WE THEN RESTARTED THE ENG ACCORDING TO THE CHKLIST AND IT APPEARED TO RUN NORMALLY FOR THE DURATION OF THE FLT. ATC WAS NOT NOTIFIED AS WE RECTIFIED THE PROB WITHOUT HAVING TO DEVIATE FROM ANY CLRNCS. THE ENG APPEARED TO BE OPERATING NORMALLY. THIS IS REPORTED TO BE A FAIRLY COMMON PROB WITH THE ENGS ON THE DC10-40, PRATT & WHITNEY. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE PLT'S ACR HAS HAD SUCH A PROB WITH THIS ENG THAT THERE IS A SPECIAL THROTTLE CLOSURE PROC IN THE FLT MANUAL. BEFORE TOUCHING THE THROTTLES FOR DSCNT, THE ENG THERMAL ANTI-ICE AND FUEL HEAT MUST BE TURNED ON AND OPERATED. THE EXTRA PNEUMATIC BLEED IS SUPPOSED TO INCREASE THE ENG STALL MARGIN. THE #2 THROTTLE IS THEN REDUCED TO IDLE OVER 10 SECONDS MINIMUM. AFTER #2 IS STABILIZED, THE SAME PROC IS USED TO RETARD #1 AND #3 THROTTLES. THE CREW USED THIS PROC THIS TIME BUT IT DID NOT PREVENT A STALL AND EGT RUNAWAY. THIS PLT FLEW THIS ACFT SEVERAL DAYS LATER AND MAINT ACCOMPLISHED THE PRESCRIBED INSPECTIONS WITHOUT FINDING ANY PROBS. THE VERY NEXT FLT THE ITEM REPEATED AND THE ACR FERRIED THE ACFT TO ITS MAIN MAINT BASE FOR AN ENG CHANGE. THE PLT HAS SEEN THIS BEFORE ON BOTH B747'S AND DC10'S. HE WONDERED WHY, AFTER ALL THIS TIME, THAT PRATT & WHITNEY IS INCAPABLE OF FIXING THE PROB.
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.