B747-400 diverts to alternate as wiring to recirculation fan causes smoke in the cabin.

Attributes
ACN	352401
Time
Date	199611
Day	Tue
Local Time Of Day	0001 To 0600
Place
Locale Reference	atc facility : zzz
State Reference	US
Altitude	msl bound lower : 37000 msl bound upper : 37000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B747-400
Operating Under FAR Part	Part 121
Navigation In Use	Other Other
Flight Phase	cruise other other other
Route In Use	enroute : pacific
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 88 flight time total : 14674 flight time type : 545
ASRS Report	352401
Person 2
Affiliation	company : air carrier
Function	other personnel other
Qualification	pilot : instrument pilot : atp pilot : commercial pilot : flight engineer
Experience	flight time last 90 days : 200 flight time total : 16000
ASRS Report	352413
Events
Anomaly	aircraft equipment problem : critical
Independent Detector	other flight crewa other other : unspecified
Resolutory Action	flight crew : declared emergency none taken : unable
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

Cruising at FL370 from WWW to XXX. At about 33:300 north 155 east, flight attendant reports to pilots that there is smoke in aft cabin. Pilots wake third crew member from bunk to check problem. Pilots flying begin diversion to YYY airport. Galley, gasper fans were turned off. Third crew member reports back to pilots flying that there is smoke in cabin but does not seem to be getting worse. We receive status message recirculation fan lower right indicating problem with fan. We land at YYY without further problems. Maintenance reports the wiring in recirculation fan lower right was cause of problem. Supplemental information from acn 352413: landed in YYY after curfew so an emergency was necessary. Aircraft deplaned with no further problem. Maintenance determined a recirculation fan (lower) froze up causing the problem.

Original NASA ASRS Text

Title: B747-400 DIVERTS TO ALTERNATE AS WIRING TO RECIRCULATION FAN CAUSES SMOKE IN THE CABIN.

Narrative: CRUISING AT FL370 FROM WWW TO XXX. AT ABOUT 33:300 N 155 E, FLT ATTENDANT RPTS TO PLTS THAT THERE IS SMOKE IN AFT CABIN. PLTS WAKE THIRD CREW MEMBER FROM BUNK TO CHK PROB. PLTS FLYING BEGIN DIVERSION TO YYY ARPT. GALLEY, GASPER FANS WERE TURNED OFF. THIRD CREW MEMBER RPTS BACK TO PLTS FLYING THAT THERE IS SMOKE IN CABIN BUT DOES NOT SEEM TO BE GETTING WORSE. WE RECEIVE STATUS MESSAGE RECIRCULATION FAN LOWER R INDICATING PROB WITH FAN. WE LAND AT YYY WITHOUT FURTHER PROBS. MAINT RPTS THE WIRING IN RECIRCULATION FAN LOWER R WAS CAUSE OF PROB. SUPPLEMENTAL INFO FROM ACN 352413: LANDED IN YYY AFTER CURFEW SO AN EMER WAS NECESSARY. ACFT DEPLANED WITH NO FURTHER PROB. MAINT DETERMINED A RECIRCULATION FAN (LOWER) FROZE UP CAUSING 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.