An air carrier large transport crew had an in-flight engine shutdown. Emergency declared.

Attributes
ACN	356586
Time
Date	199612
Day	Thu
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : dsm
State Reference	IA
Altitude	msl bound lower : 31000 msl bound upper : 31000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zkc
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other other other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : flight engineer pilot : cfi pilot : atp
Experience	flight time last 90 days : 150 flight time total : 8500 flight time type : 600
ASRS Report	356586
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : declared emergency other
Consequence	other
Supplementary
Primary Problem	Aircraft

Narrative:

Upon leveloff at FL310, power was reduced to cruise setting. At this time a compressor stall was heard as evidenced by a loud rumble and bang with erratic indications on #2 engine. Power was reduced slightly more and the problem occurred again. We realized that we had an engine problem so the thrust lever was reduced to idle power. All engine indications were normal at idle power with no compressor stalls. We decided to return to our departure airport and declared an emergency. The landing was uneventful. We chose to return to our departure airport as it was the most familiar and allowed us enough time to complete all checklists and prepare the aircraft for landing in an unhurried manner.

Original NASA ASRS Text

Title: AN ACR LGT CREW HAD AN INFLT ENG SHUTDOWN. EMER DECLARED.

Narrative: UPON LEVELOFF AT FL310, PWR WAS REDUCED TO CRUISE SETTING. AT THIS TIME A COMPRESSOR STALL WAS HEARD AS EVIDENCED BY A LOUD RUMBLE AND BANG WITH ERRATIC INDICATIONS ON #2 ENG. PWR WAS REDUCED SLIGHTLY MORE AND THE PROB OCCURRED AGAIN. WE REALIZED THAT WE HAD AN ENG PROB SO THE THRUST LEVER WAS REDUCED TO IDLE PWR. ALL ENG INDICATIONS WERE NORMAL AT IDLE PWR WITH NO COMPRESSOR STALLS. WE DECIDED TO RETURN TO OUR DEP ARPT AND DECLARED AN EMER. THE LNDG WAS UNEVENTFUL. WE CHOSE TO RETURN TO OUR DEP ARPT AS IT WAS THE MOST FAMILIAR AND ALLOWED US ENOUGH TIME TO COMPLETE ALL CHKLISTS AND PREPARE THE ACFT FOR LNDG IN AN UNHURRIED MANNER.

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.