Cargo aircraft has engine fire warning. Unable to extinguish, emergency declared.

Attributes
ACN	301442
Time
Date	199504
Day	Thu
Local Time Of Day	0601 To 1200
Place
Locale Reference	atc facility : den
State Reference	CO
Altitude	msl bound lower : 28000 msl bound upper : 28000
Environment
Flight Conditions	VMC
Light	Night
Aircraft 1
Controlling Facilities	artcc : zdv tower : fok
Operator	common carrier : air carrier
Make Model Name	Commercial Fixed Wing
Operating Under FAR Part	Part 121
Flight Phase	cruise other
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : captain oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 150 flight time total : 12000 flight time type : 3000
ASRS Report	301442
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : atp pilot : instrument pilot : commercial
Events
Anomaly	aircraft equipment problem : less severe other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : unspecified
Resolutory Action	flight crew : declared emergency other
Consequence	Other
Supplementary
Primary Problem	Aircraft

Narrative:

During cruise flight in the vicinity of lbf, #4 fire bell and warning sounded. Accomplished engine securing checklist. Extinguished 1 bottle fire extinguisher into that engine. Fire loop light extinguished for 5 seconds. After 30 seconds, fire bottle #2 was used. Fire light remained on. Declared emergency with ZDV. Requested and received direct den with equipment standing by. Made overweight landing den, stopped on runway. Fire department reported no fire existed. Taxied to ramp. Note: maintenance reported fire loop grounded by cannon plug by oil.

Original NASA ASRS Text

Title: CARGO ACFT HAS ENG FIRE WARNING. UNABLE TO EXTINGUISH, EMER DECLARED.

Narrative: DURING CRUISE FLT IN THE VICINITY OF LBF, #4 FIRE BELL AND WARNING SOUNDED. ACCOMPLISHED ENG SECURING CHKLIST. EXTINGUISHED 1 BOTTLE FIRE EXTINGUISHER INTO THAT ENG. FIRE LOOP LIGHT EXTINGUISHED FOR 5 SECONDS. AFTER 30 SECONDS, FIRE BOTTLE #2 WAS USED. FIRE LIGHT REMAINED ON. DECLARED EMER WITH ZDV. REQUESTED AND RECEIVED DIRECT DEN WITH EQUIP STANDING BY. MADE OVERWT LNDG DEN, STOPPED ON RWY. FIRE DEPT RPTED NO FIRE EXISTED. TAXIED TO RAMP. NOTE: MAINT RPTED FIRE LOOP GNDED BY CANNON PLUG BY OIL.

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.