Narrative:

I fly as a first officer aboard an F27 for a cargo company, 2 crew members on board. We were en route from ont to sba (40 min flight). 25 mins into the flight, just past fillmore VOR, we had a fire warning light with a bell, come on. I was flying, we were at cruise, 6000 ft. The captain silenced the bell, the light stayed illuminated, indicating the right engine fire. From my window in the cockpit, I can see all but the last foot of the engine. The exhaust pipe is on the outboard of the nacelle, so I was unable to see that. I asked the captain to fly, so I could get a good look at the engine. I could see no fire or smoke which I conveyed to the captain. I said 'we will still have to shut it down because the light is illuminated.' he hesitantly agreed. He was still flying, while I went through the checklist. In 4 steps the engine was shut down. The next step on the checklist reads 'if fire exists' fire bottle #1...fire. With the first warning light still illuminated, I told the captain to fire #1. He decided to check the engine himself and did not want to shoot the fire bottle. The captain had me take the controls while he stood behind my seat to look out the window. He said there was no visual sign that fire exists. I informed him the light was still on, and there was no way to see inside the cowling, and the fire bottle must be shot. The captain felt it was a false alarm and would put the airplane out of commission much longer than necessary, with the possibility of corrosion to the engine from the retardant. The debate continued for a total of about 2 mins. We did not fire the bottles. The captain's decision was based on not only a visual check, but also engine indications being normal. Based on our company training, we are required to comply with the checklist, which states: feather the engine, shut off fuel, and discharge fire extinguisher. Throughout the emergency I insisted we follow the checklist. The captain then walked to the cabin of the aircraft, to see if he could visually see a fire. From the back, it is not possible to see out, because all of the windows have been covered. While he was in the back, I yelled to him, asking for a message to give ATC. He said 'tell them we did a precautionary shutdown.' I told him we needed to declare an emergency, he then agreed. With the information passed to ATC, the captain asked if I wanted to continue to sba (10 mins away). I said 'no, not with that light still on. I realize we're holding altitude, but how do we explain flying all the way over water?' (from camarillo the approach into sba is out over the ocean.) the captain informed me that cma airport was directly below us and we could land there, he was now flying and I called socal and requested landing at cma. When handed over to cma tower the controller asked if we wanted the trucks. We asked for a fire truck. The captain made a beautiful single engine landing. We rolled out and avoided initially using the reversers. We asked for permission to shut down on the taxiway. As we got out and checked the engine, which had no evidence of fire, I realized I should have taken the initiative to inform ATC of the complete emergency status because it took the trucks 2- 3 mins to respond. Our mechanic found a faulty fire detection loop. That was all.

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Original NASA ASRS Text

Title: A FOKKER 27 AT 6000 FT DECLARED AN EMER AND DIVERTED DUE TO #2 ENG FIRE WARNING LIGHT AND BELL CAUSED BY A FAULTY FIRE DETECTION LOOP.

Narrative: I FLY AS A FO ABOARD AN F27 FOR A CARGO COMPANY, 2 CREW MEMBERS ON BOARD. WE WERE ENRTE FROM ONT TO SBA (40 MIN FLT). 25 MINS INTO THE FLT, JUST PAST FILLMORE VOR, WE HAD A FIRE WARNING LIGHT WITH A BELL, COME ON. I WAS FLYING, WE WERE AT CRUISE, 6000 FT. THE CAPT SILENCED THE BELL, THE LIGHT STAYED ILLUMINATED, INDICATING THE R ENG FIRE. FROM MY WINDOW IN THE COCKPIT, I CAN SEE ALL BUT THE LAST FOOT OF THE ENG. THE EXHAUST PIPE IS ON THE OUTBOARD OF THE NACELLE, SO I WAS UNABLE TO SEE THAT. I ASKED THE CAPT TO FLY, SO I COULD GET A GOOD LOOK AT THE ENG. I COULD SEE NO FIRE OR SMOKE WHICH I CONVEYED TO THE CAPT. I SAID 'WE WILL STILL HAVE TO SHUT IT DOWN BECAUSE THE LIGHT IS ILLUMINATED.' HE HESITANTLY AGREED. HE WAS STILL FLYING, WHILE I WENT THROUGH THE CHKLIST. IN 4 STEPS THE ENG WAS SHUT DOWN. THE NEXT STEP ON THE CHKLIST READS 'IF FIRE EXISTS' FIRE BOTTLE #1...FIRE. WITH THE FIRST WARNING LIGHT STILL ILLUMINATED, I TOLD THE CAPT TO FIRE #1. HE DECIDED TO CHK THE ENG HIMSELF AND DID NOT WANT TO SHOOT THE FIRE BOTTLE. THE CAPT HAD ME TAKE THE CTLS WHILE HE STOOD BEHIND MY SEAT TO LOOK OUT THE WINDOW. HE SAID THERE WAS NO VISUAL SIGN THAT FIRE EXISTS. I INFORMED HIM THE LIGHT WAS STILL ON, AND THERE WAS NO WAY TO SEE INSIDE THE COWLING, AND THE FIRE BOTTLE MUST BE SHOT. THE CAPT FELT IT WAS A FALSE ALARM AND WOULD PUT THE AIRPLANE OUT OF COMMISSION MUCH LONGER THAN NECESSARY, WITH THE POSSIBILITY OF CORROSION TO THE ENG FROM THE RETARDANT. THE DEBATE CONTINUED FOR A TOTAL OF ABOUT 2 MINS. WE DID NOT FIRE THE BOTTLES. THE CAPT'S DECISION WAS BASED ON NOT ONLY A VISUAL CHK, BUT ALSO ENG INDICATIONS BEING NORMAL. BASED ON OUR COMPANY TRAINING, WE ARE REQUIRED TO COMPLY WITH THE CHKLIST, WHICH STATES: FEATHER THE ENG, SHUT OFF FUEL, AND DISCHARGE FIRE EXTINGUISHER. THROUGHOUT THE EMER I INSISTED WE FOLLOW THE CHKLIST. THE CAPT THEN WALKED TO THE CABIN OF THE ACFT, TO SEE IF HE COULD VISUALLY SEE A FIRE. FROM THE BACK, IT IS NOT POSSIBLE TO SEE OUT, BECAUSE ALL OF THE WINDOWS HAVE BEEN COVERED. WHILE HE WAS IN THE BACK, I YELLED TO HIM, ASKING FOR A MESSAGE TO GIVE ATC. HE SAID 'TELL THEM WE DID A PRECAUTIONARY SHUTDOWN.' I TOLD HIM WE NEEDED TO DECLARE AN EMER, HE THEN AGREED. WITH THE INFO PASSED TO ATC, THE CAPT ASKED IF I WANTED TO CONTINUE TO SBA (10 MINS AWAY). I SAID 'NO, NOT WITH THAT LIGHT STILL ON. I REALIZE WE'RE HOLDING ALT, BUT HOW DO WE EXPLAIN FLYING ALL THE WAY OVER WATER?' (FROM CAMARILLO THE APCH INTO SBA IS OUT OVER THE OCEAN.) THE CAPT INFORMED ME THAT CMA ARPT WAS DIRECTLY BELOW US AND WE COULD LAND THERE, HE WAS NOW FLYING AND I CALLED SOCAL AND REQUESTED LNDG AT CMA. WHEN HANDED OVER TO CMA TWR THE CTLR ASKED IF WE WANTED THE TRUCKS. WE ASKED FOR A FIRE TRUCK. THE CAPT MADE A BEAUTIFUL SINGLE ENG LNDG. WE ROLLED OUT AND AVOIDED INITIALLY USING THE REVERSERS. WE ASKED FOR PERMISSION TO SHUT DOWN ON THE TXWY. AS WE GOT OUT AND CHKED THE ENG, WHICH HAD NO EVIDENCE OF FIRE, I REALIZED I SHOULD HAVE TAKEN THE INITIATIVE TO INFORM ATC OF THE COMPLETE EMER STATUS BECAUSE IT TOOK THE TRUCKS 2- 3 MINS TO RESPOND. OUR MECH FOUND A FAULTY FIRE DETECTION LOOP. THAT WAS ALL.

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.