WX turbulence results in #4 engine compressor stall resulting in engine shutdown.

Attributes
ACN	193073
Time
Date	199110
Day	Sun
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : unz
State Reference	FO
Altitude	msl bound lower : 35700 msl bound upper : 38500
Environment
Flight Conditions	Mixed
Light	Dawn
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	Widebody, Low Wing, 4 Turbojet Eng
Navigation In Use	Other
Flight Phase	climbout : intermediate altitude
Route In Use	enroute : other oceanic enroute : pacific enroute airway : b586
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : instrument pilot : commercial pilot : atp
Experience	flight time last 90 days : 70 flight time total : 17000 flight time type : 2300
ASRS Report	193073
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical inflight encounter : weather other anomaly other
Independent Detector	other flight crewa
Resolutory Action	controller : issued new clearance other
Consequence	Other
Supplementary
Primary Problem	Flight Crew Human Performance
Air Traffic Incident	Pilot Deviation

Narrative:

We were cleared to climb to FL390. Passing FL385 we passed through the top of a WX front with resulting moderate turbulence and possible icing. The #4 engine compressor stalled with resulting maximum exhaust gas temperature. The engine was shut down immediately to cool down and followed by in-flight restart. In the process, however, we had to begin descending to maintain airspeed. An immediate 90 degree left turn off of the airway was made and we requested FL330. While awaiting clearance to FL330 we drifted down as low as FL357 and were cleared 'to turn sbound and once heading south to descend to FL330.' we maintained FL357 until heading south and then descended to FL330. Passing down through FL350 a successful engine relight was accomplished. We continued down to FL330, and then rejoined the airway (B-586), and returned back on course to the north and on to our original destination without further incident. An 'emergency' was not declared. We were clear of clouds during our entire descent and visually checking for traffic but still it was uncomfortable descending while initially awaiting a clearance to do so. In retrospect, I believe it would probably have been better to have 'declared an emergency' and let ATC try to move traffic which was at FL350.

Original NASA ASRS Text

Title: WX TURB RESULTS IN #4 ENG COMPRESSOR STALL RESULTING IN ENG SHUTDOWN.

Narrative: WE WERE CLRED TO CLB TO FL390. PASSING FL385 WE PASSED THROUGH THE TOP OF A WX FRONT WITH RESULTING MODERATE TURB AND POSSIBLE ICING. THE #4 ENG COMPRESSOR STALLED WITH RESULTING MAX EXHAUST GAS TEMP. THE ENG WAS SHUT DOWN IMMEDIATELY TO COOL DOWN AND FOLLOWED BY INFLT RESTART. IN THE PROCESS, HOWEVER, WE HAD TO BEGIN DSNDING TO MAINTAIN AIRSPD. AN IMMEDIATE 90 DEG L TURN OFF OF THE AIRWAY WAS MADE AND WE REQUESTED FL330. WHILE AWAITING CLRNC TO FL330 WE DRIFTED DOWN AS LOW AS FL357 AND WERE CLRED 'TO TURN SBOUND AND ONCE HDG S TO DSND TO FL330.' WE MAINTAINED FL357 UNTIL HDG S AND THEN DSNDED TO FL330. PASSING DOWN THROUGH FL350 A SUCCESSFUL ENG RELIGHT WAS ACCOMPLISHED. WE CONTINUED DOWN TO FL330, AND THEN REJOINED THE AIRWAY (B-586), AND RETURNED BACK ON COURSE TO THE N AND ON TO OUR ORIGINAL DEST WITHOUT FURTHER INCIDENT. AN 'EMER' WAS NOT DECLARED. WE WERE CLR OF CLOUDS DURING OUR ENTIRE DSCNT AND VISUALLY CHKING FOR TFC BUT STILL IT WAS UNCOMFORTABLE DSNDING WHILE INITIALLY AWAITING A CLRNC TO DO SO. IN RETROSPECT, I BELIEVE IT WOULD PROBABLY HAVE BEEN BETTER TO HAVE 'DECLARED AN EMER' AND LET ATC TRY TO MOVE TFC WHICH WAS AT FL350.

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.