An medium large transport air carrier crew had a false APU fire warning.

Attributes
ACN	233380
Time
Date	199302
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	atc facility : vcn
State Reference	NJ
Altitude	msl bound lower : 15000 msl bound upper : 15000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	artcc : zny
Operator	common carrier : air carrier
Make Model Name	Medium Large Transport, Low Wing, 2 Turbojet Eng
Navigation In Use	Other Other
Flight Phase	descent other
Route In Use	arrival other arrival star : star
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp
Experience	flight time last 90 days : 180 flight time total : 8000 flight time type : 1000
ASRS Report	233380
Person 2
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified other flight crewa
Resolutory Action	flight crew : declared emergency flight crew : overcame equipment problem
Consequence	Other
Supplementary
Primary Problem	Aircraft
Air Traffic Incident	other

Narrative:

MFDU showed 'APU fire' warn without aural warning (no triple chime). Aircraft had been airborne for several mins with APU off. Upon investigation, the engine fire checklist was displayed under the 'APU fire' label on MFDU. No bottle was fired automatically for the APU. After exhausting all resources, we concluded it was a false alarm, however, as a precaution, decided to treat the alarm as if it were real. Equipment was called out in phl. Fire department confirmed no smoke or fire once on the ground. Normal descent and landing.

Original NASA ASRS Text

Title: AN MLG ACR CREW HAD A FALSE APU FIRE WARNING.

Narrative: MFDU SHOWED 'APU FIRE' WARN WITHOUT AURAL WARNING (NO TRIPLE CHIME). ACFT HAD BEEN AIRBORNE FOR SEVERAL MINS WITH APU OFF. UPON INVESTIGATION, THE ENG FIRE CHKLIST WAS DISPLAYED UNDER THE 'APU FIRE' LABEL ON MFDU. NO BOTTLE WAS FIRED AUTOMATICALLY FOR THE APU. AFTER EXHAUSTING ALL RESOURCES, WE CONCLUDED IT WAS A FALSE ALARM, HOWEVER, AS A PRECAUTION, DECIDED TO TREAT THE ALARM AS IF IT WERE REAL. EQUIP WAS CALLED OUT IN PHL. FIRE DEPT CONFIRMED NO SMOKE OR FIRE ONCE ON THE GND. NORMAL DSCNT AND LNDG.

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.