B737-300 flight crew has APU fire warning while at cruise; diverts and lands without incident.

Attributes
ACN	697658
Time
Date	200605
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : zse.artcc
State Reference	WA
Altitude	msl single value : 32000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zse.artcc
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	cruise : level
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 : 13000 flight time type : 7000
ASRS Report	697658
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Experience	flight time last 90 days : 185 flight time total : 7500 flight time type : 3500
ASRS Report	697988
Events
Anomaly	aircraft equipment problem : critical other anomaly
Independent Detector	aircraft equipment other aircraft equipment : apu fire warning other flight crewa other flight crewb
Resolutory Action	flight crew : landed as precaution flight crew : diverted to another airport
Consequence	other other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance
Primary Problem	Aircraft

Narrative:

At FL320; we got an APU fire light and bell warning. The APU had been off for approximately 40 mins; with all the normal off indications. We referred to the QRH and accomplished all the items. The fire light went out and the fire circuit checked good. A few mins later the fire light came back on and went out. The fire circuit still checked good. We had a flight attendant proceed to the aft galley to check for anything out of the ordinary. She replied that there were no strange odors or vibrations. We contacted dispatch and maintenance control; and told them the situation and that pdx was our closest suitable landing airport. Approach; landing and taxi were uneventful. Supplemental information from acn 697988: we contacted dispatch and maintenance control to determine if there were any known issues with the jet. On the ground in about 20 mins. This appeared to be an erroneous fire light; but everything was done in accordance with the QRH.

Original NASA ASRS Text

Title: B737-300 FLT CREW HAS APU FIRE WARNING WHILE AT CRUISE; DIVERTS AND LANDS WITHOUT INCIDENT.

Narrative: AT FL320; WE GOT AN APU FIRE LIGHT AND BELL WARNING. THE APU HAD BEEN OFF FOR APPROX 40 MINS; WITH ALL THE NORMAL OFF INDICATIONS. WE REFERRED TO THE QRH AND ACCOMPLISHED ALL THE ITEMS. THE FIRE LIGHT WENT OUT AND THE FIRE CIRCUIT CHKED GOOD. A FEW MINS LATER THE FIRE LIGHT CAME BACK ON AND WENT OUT. THE FIRE CIRCUIT STILL CHKED GOOD. WE HAD A FLT ATTENDANT PROCEED TO THE AFT GALLEY TO CHK FOR ANYTHING OUT OF THE ORDINARY. SHE REPLIED THAT THERE WERE NO STRANGE ODORS OR VIBRATIONS. WE CONTACTED DISPATCH AND MAINT CTL; AND TOLD THEM THE SIT AND THAT PDX WAS OUR CLOSEST SUITABLE LNDG ARPT. APCH; LNDG AND TAXI WERE UNEVENTFUL. SUPPLEMENTAL INFO FROM ACN 697988: WE CONTACTED DISPATCH AND MAINT CTL TO DETERMINE IF THERE WERE ANY KNOWN ISSUES WITH THE JET. ON THE GND IN ABOUT 20 MINS. THIS APPEARED TO BE AN ERRONEOUS FIRE LIGHT; BUT EVERYTHING WAS DONE IN ACCORDANCE WITH THE QRH.

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.