Widebody transport forced to descend when an engine experiences compressor stalls.

Attributes
ACN	93847
Time
Date	198809
Day	Wed
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : slc
State Reference	UT
Altitude	msl bound lower : 41000 msl bound upper : 41000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zlc
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	cruise 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 : 100 flight time total : 15000
ASRS Report	93847
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : critical altitude deviation : excursion from assigned altitude
Independent Detector	other flight crewa
Resolutory Action	aircraft : equipment problem dissipated controller : issued new clearance flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

At cruise FL410 we had flown past our descent point account FL390 traffic (traffic in sight). We began a small speed reduction from cruise 240 KIAS, and upon passing 228 KTS IAS we experienced engine compressor stalling. We increased power, however stalls continued. I advised ATC that we were leaving FL410 for a lower altitude with compressor stalls and an engine problem. We were immediately given descent clearance to 15000'. By now the stalling had stopped and engines were at idle power. I reported to ATC that the problem had ceased any that no assistance was required. We made a normal landing at our destination, slc. No emergency or priority was declared and no report to the FAA was filed.

Original NASA ASRS Text

Title: WDB FORCED TO DESCEND WHEN AN ENGINE EXPERIENCES COMPRESSOR STALLS.

Narrative: AT CRUISE FL410 WE HAD FLOWN PAST OUR DSCNT POINT ACCOUNT FL390 TFC (TFC IN SIGHT). WE BEGAN A SMALL SPD REDUCTION FROM CRUISE 240 KIAS, AND UPON PASSING 228 KTS IAS WE EXPERIENCED ENG COMPRESSOR STALLING. WE INCREASED PWR, HOWEVER STALLS CONTINUED. I ADVISED ATC THAT WE WERE LEAVING FL410 FOR A LOWER ALT WITH COMPRESSOR STALLS AND AN ENG PROB. WE WERE IMMEDIATELY GIVEN DSCNT CLRNC TO 15000'. BY NOW THE STALLING HAD STOPPED AND ENGS WERE AT IDLE PWR. I RPTED TO ATC THAT THE PROB HAD CEASED ANY THAT NO ASSISTANCE WAS REQUIRED. WE MADE A NORMAL LNDG AT OUR DEST, SLC. NO EMER OR PRIORITY WAS DECLARED AND NO RPT TO THE FAA WAS FILED.

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.