An MD11 on approach at 10000 ft declared an emergency due to a false fire warning on #3 engine cause...

Attributes
ACN	488802
Time
Date	200010
Day	Tue
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : rjnn.airport
State Reference	FO
Altitude	msl single value : 10000
Environment
Flight Conditions	VMC
Light	Daylight
Aircraft 1
Controlling Facilities	tracon : rjnn.tracon tower : oak.tower
Operator	common carrier : air carrier
Make Model Name	MD-11
Operating Under FAR Part	Part 121
Navigation In Use	other
Flight Phase	descent : approach
Route In Use	arrival : on vectors
Flight Plan	IFR
Person 1
Affiliation	company : air carrier
Function	flight crew : first officer
Qualification	pilot : cfi pilot : flight engineer pilot : atp
Experience	flight time last 90 days : 150 flight time total : 11000 flight time type : 5000
ASRS Report	488802
Person 2
Affiliation	company : air carrier
Function	flight crew : relief pilot
Qualification	pilot : multi engine pilot : instrument pilot : flight engineer pilot : commercial pilot : atp
Experience	flight time last 90 days : 115 flight time total : 9600 flight time type : 1350
ASRS Report	488815
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	aircraft equipment other aircraft equipment : #3 engine fire warning other flight crewa other flight crewb other other : 3
Resolutory Action	flight crew : declared emergency
Consequence	other other
Supplementary
Problem Areas	Aircraft Flight Crew Human Performance Chart Or Publication
Primary Problem	Aircraft
Situations
Publication	PILOT OPERATING MANUAL

Narrative:

Approaching nagoya airport, #3 engine fire warning came on. Accomplished checklist procedures per aircraft pom. Engine shut down, fire handle pulled and attempted to discharge fire bottles at 5 min intervals (fire bottle #1, then after 5 mins, fired second bottle). Did not get agent low lights confirming bottles were discharged. Apparently MD11 requires excessive force to discharge bottles. Declared emergency, visually checked engine from cabin and no apparent fire. Landed without event. Maintenance found fire detection box for #3 engine faulty and replaced it. Bottle firing mechanism was verified in working order and aircraft was dispatched back to ZZZ via portland, or. Maintenance in ZZZ took aircraft to hangar and discharged bottles from cockpit to further verify that engine fire panel was working correctly. Again it seems that the MD11 aircraft requires an excessive amount of force to discharge fire bottles. Callback conversation with reporter revealed the following information: the reporter stated the pom was used to shut down the engine, and discharge the engine fire extinguisher. The reporter said during the emergency the fire handle was pulled down shutting off pneumatics, electrical power, hydraulics and fuel then rotated to fire the engine fire bottles. The reporter stated when the handle was rotated the bottles did not fire as no bottle low pressure warning lights were illuminated and later it was found 26 pounds of handle rotational force was required. The reporter said the simulator rotational force was much less and no where near the actual airplane. The reporter said the carrier issued an immediate alert bulletin covering the rotational force required.

Original NASA ASRS Text

Title: AN MD11 ON APCH AT 10000 FT DECLARED AN EMER DUE TO A FALSE FIRE WARNING ON #3 ENG CAUSED BY A FAILED ENG FIRE DETECTION BOX. CREW WAS UNABLE TO DISCHARGE THE FIRE BOTTLES DUE TO FIRE HANDLE FORCE.

Narrative: APCHING NAGOYA ARPT, #3 ENG FIRE WARNING CAME ON. ACCOMPLISHED CHKLIST PROCS PER ACFT POM. ENG SHUT DOWN, FIRE HANDLE PULLED AND ATTEMPTED TO DISCHARGE FIRE BOTTLES AT 5 MIN INTERVALS (FIRE BOTTLE #1, THEN AFTER 5 MINS, FIRED SECOND BOTTLE). DID NOT GET AGENT LOW LIGHTS CONFIRMING BOTTLES WERE DISCHARGED. APPARENTLY MD11 REQUIRES EXCESSIVE FORCE TO DISCHARGE BOTTLES. DECLARED EMER, VISUALLY CHKED ENG FROM CABIN AND NO APPARENT FIRE. LANDED WITHOUT EVENT. MAINT FOUND FIRE DETECTION BOX FOR #3 ENG FAULTY AND REPLACED IT. BOTTLE FIRING MECHANISM WAS VERIFIED IN WORKING ORDER AND ACFT WAS DISPATCHED BACK TO ZZZ VIA PORTLAND, OR. MAINT IN ZZZ TOOK ACFT TO HANGAR AND DISCHARGED BOTTLES FROM COCKPIT TO FURTHER VERIFY THAT ENG FIRE PANEL WAS WORKING CORRECTLY. AGAIN IT SEEMS THAT THE MD11 ACFT REQUIRES AN EXCESSIVE AMOUNT OF FORCE TO DISCHARGE FIRE BOTTLES. CALLBACK CONVERSATION WITH RPTR REVEALED THE FOLLOWING INFO: THE RPTR STATED THE POM WAS USED TO SHUT DOWN THE ENG, AND DISCHARGE THE ENG FIRE EXTINGUISHER. THE RPTR SAID DURING THE EMER THE FIRE HANDLE WAS PULLED DOWN SHUTTING OFF PNEUMATICS, ELECTRICAL PWR, HYDS AND FUEL THEN ROTATED TO FIRE THE ENG FIRE BOTTLES. THE RPTR STATED WHEN THE HANDLE WAS ROTATED THE BOTTLES DID NOT FIRE AS NO BOTTLE LOW PRESSURE WARNING LIGHTS WERE ILLUMINATED AND LATER IT WAS FOUND 26 LBS OF HANDLE ROTATIONAL FORCE WAS REQUIRED. THE RPTR SAID THE SIMULATOR ROTATIONAL FORCE WAS MUCH LESS AND NO WHERE NEAR THE ACTUAL AIRPLANE. THE RPTR SAID THE CARRIER ISSUED AN IMMEDIATE ALERT BULLETIN COVERING THE ROTATIONAL FORCE REQUIRED.

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.

An MD11 on approach at 10000 ft declared an emergency due to a false fire warning on #3 engine caused by a failed engine fire detection box. Crew was unable to discharge the fire bottles due to fire handle force.