SF340 12 mi on final approach declared an emergency due to avionics smoke light illuminated on warni...

Attributes
ACN	647070
Time
Date	200502
Place
Locale Reference	airport : zzz.airport
State Reference	US
Environment
Flight Conditions	IMC
Aircraft 1
Controlling Facilities	tracon : zzz.tracon
Operator	common carrier : air carrier
Make Model Name	SF 340B
Operating Under FAR Part	Part 121
Flight Phase	descent : intermediate altitude
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
ASRS Report	647070
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
ASRS Report	647074
Events
Anomaly	aircraft equipment problem : critical other anomaly
Independent Detector	aircraft equipment other aircraft equipment : avionics smoke warning other flight crewa other flight crewb
Resolutory Action	flight crew : declared emergency
Consequence	other other
Supplementary
Problem Areas	Weather Aircraft
Primary Problem	Aircraft

Narrative:

12 mi from ZZZ; avionics smoke light came on caution warning panel. First officer's leg. I ran the procedure and confirmed with the flight attendant if any indication of fire or smoke; as there was none. In the existing WX in ZZZ (which was IFR); we opted to declare an emergency and get priority for landing. At 6 mi final; the avionics light on the caution warning panel turned off. The flight attendant was briefed to evacuate/evacuation on the right side of the aircraft if needed. Crash fire rescue equipment was available in ZZZ on the ground; but not required. Callback conversation with reporter revealed the following information: the reporter stated the smoke warning turned out to be a false warning as no fumes or smell were noted in the air. On the ground; maintenance inspected the avionics compartment and tested the smoke system and found all ok. Maintenance may have replaced some component in the smoke warning system precautionary; but did not advise the crew.

Original NASA ASRS Text

Title: SF340 12 MI ON FINAL APCH DECLARED AN EMER DUE TO AVIONICS SMOKE LIGHT ILLUMINATED ON WARNING PANEL. NO SMELL OR FUMES NOTED.

Narrative: 12 MI FROM ZZZ; AVIONICS SMOKE LIGHT CAME ON CAUTION WARNING PANEL. FO'S LEG. I RAN THE PROC AND CONFIRMED WITH THE FLT ATTENDANT IF ANY INDICATION OF FIRE OR SMOKE; AS THERE WAS NONE. IN THE EXISTING WX IN ZZZ (WHICH WAS IFR); WE OPTED TO DECLARE AN EMER AND GET PRIORITY FOR LNDG. AT 6 MI FINAL; THE AVIONICS LIGHT ON THE CAUTION WARNING PANEL TURNED OFF. THE FLT ATTENDANT WAS BRIEFED TO EVAC ON THE R SIDE OF THE ACFT IF NEEDED. CFR WAS AVAILABLE IN ZZZ ON THE GND; BUT NOT REQUIRED. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE SMOKE WARNING TURNED OUT TO BE A FALSE WARNING AS NO FUMES OR SMELL WERE NOTED IN THE AIR. ON THE GND; MAINT INSPECTED THE AVIONICS COMPARTMENT AND TESTED THE SMOKE SYS AND FOUND ALL OK. MAINT MAY HAVE REPLACED SOME COMPONENT IN THE SMOKE WARNING SYS PRECAUTIONARY; BUT DID NOT ADVISE THE CREW.

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.

SF340 12 mi on final approach declared an emergency due to avionics smoke light illuminated on warning panel. No smell or fumes noted.