A B737-300 on autoplt during descent one engine throttle came back almost to idle. Pushed throttle u...

Attributes
ACN	712726
Time
Date	200610
Local Time Of Day	1801 To 2400
Place
Locale Reference	atc facility : zdv.artcc
State Reference	CO
Altitude	msl single value : 31000
Environment
Flight Conditions	VMC
Aircraft 1
Controlling Facilities	artcc : zdv.artcc
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	descent : approach
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Experience	flight time last 90 days : 200 flight time total : 22000 flight time type : 10000
ASRS Report	712726
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact
Consequence	other other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft

Narrative:

Captain flying on autoplt. Given descent to FL310. During descent; throttle came back to almost idle and speed got a little slow. Pushed throttle up to regain the selected speed and after about 1/2 inch of throttle movement; heard a thud through the aircraft. We were busy with descent and with no abnormal engine parameters noted; continued. After landing; we wrote up the thud we heard and maintenance technician met aircraft and debriefed with us. Then took aircraft OTS with suspect compressor stall. Took aircraft to hangar and they did some checks and I got another call in my hotel maintenance needed to get more information. I then briefed with him and I said and that it really should be test flown to see if they could duplicate the problem as my first officer nor myself had ever seen or heard this. In abq; had another maintenance problem and called maintenance and asked what happened to this aircraft. He said it test flew and they were able to duplicate but this time the engine flamed out. (The thud we heard sounded like a person falling; bird strike; cart slamming into the galley; etc.)

Original NASA ASRS Text

Title: A B737-300 ON AUTOPLT DURING DSCNT ONE ENG THROTTLE CAME BACK ALMOST TO IDLE. PUSHED THROTTLE UP TO REGAIN SPD. HEARD 'THUD' WROTE UP ITEM. ON GND AIRPLANE REMOVED FROM SVC.

Narrative: CAPT FLYING ON AUTOPLT. GIVEN DSCNT TO FL310. DURING DSCNT; THROTTLE CAME BACK TO ALMOST IDLE AND SPD GOT A LITTLE SLOW. PUSHED THROTTLE UP TO REGAIN THE SELECTED SPD AND AFTER ABOUT 1/2 INCH OF THROTTLE MOVEMENT; HEARD A THUD THROUGH THE ACFT. WE WERE BUSY WITH DSCNT AND WITH NO ABNORMAL ENG PARAMETERS NOTED; CONTINUED. AFTER LNDG; WE WROTE UP THE THUD WE HEARD AND MAINT TECHNICIAN MET ACFT AND DEBRIEFED WITH US. THEN TOOK ACFT OTS WITH SUSPECT COMPRESSOR STALL. TOOK ACFT TO HANGAR AND THEY DID SOME CHKS AND I GOT ANOTHER CALL IN MY HOTEL MAINT NEEDED TO GET MORE INFO. I THEN BRIEFED WITH HIM AND I SAID AND THAT IT REALLY SHOULD BE TEST FLOWN TO SEE IF THEY COULD DUPLICATE THE PROB AS MY FO NOR MYSELF HAD EVER SEEN OR HEARD THIS. IN ABQ; HAD ANOTHER MAINT PROB AND CALLED MAINT AND ASKED WHAT HAPPENED TO THIS ACFT. HE SAID IT TEST FLEW AND THEY WERE ABLE TO DUPLICATE BUT THIS TIME THE ENG FLAMED OUT. (THE THUD WE HEARD SOUNDED LIKE A PERSON FALLING; BIRD STRIKE; CART SLAMMING INTO THE GALLEY; ETC.)

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

A B737-300 on autoplt during descent one engine throttle came back almost to idle. Pushed throttle up to regain speed. Heard 'thud' wrote up item. On ground airplane removed from service.