Narrative:

On downwind for runway 18L at cvg, an attempt was made to start the APU. We were passing through 11000 ft MSL and indicating 280 KIAS. On the attempt to start the APU, we received an APU door inhibit/closed message and the APU failed to start. This was shortly followed by an APU fire message, fire bell, and master warning. I was the PF and told the first officer that I had the radios and to run the APU fire procedure. The fire warnings stayed on for 4-8 seconds. By the time we were going to run the APU fire procedure, the fire warnings ceased. They were followed by an APU fault message. We ran the APU fault QRH procedure and the message extinguished. The flight landed without any further incident. Upon arriving at the gate, maintenance was contacted. I explained to maintenance via radio that we had an APU door inhibit message and that I wanted to speak to a mechanic due to the nature of the sequence of events that took place. When the mechanic arrived, he reset the APU ecu and restarted the APU without any problems and the APU ran normally. Upon consultation with the mechanic, the event was written up and entered into the maintenance log as an APU door inhibit message during flight. On review of company operations manual, the company requires any false fire message to be written up and entered into the maintenance log. An irregular operations report was submitted to the company explaining the situation and write-up.

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Original NASA ASRS Text

Title: CL65 CREW HAD AN 'APU DOOR CLOSED' WARNING MESSAGE, AND THEN HAD AN APU FIRE WARNING THE CREW DID NOT ACT ON THE FIRE WARNING.

Narrative: ON DOWNWIND FOR RWY 18L AT CVG, AN ATTEMPT WAS MADE TO START THE APU. WE WERE PASSING THROUGH 11000 FT MSL AND INDICATING 280 KIAS. ON THE ATTEMPT TO START THE APU, WE RECEIVED AN APU DOOR INHIBIT/CLOSED MESSAGE AND THE APU FAILED TO START. THIS WAS SHORTLY FOLLOWED BY AN APU FIRE MESSAGE, FIRE BELL, AND MASTER WARNING. I WAS THE PF AND TOLD THE FO THAT I HAD THE RADIOS AND TO RUN THE APU FIRE PROC. THE FIRE WARNINGS STAYED ON FOR 4-8 SECONDS. BY THE TIME WE WERE GOING TO RUN THE APU FIRE PROC, THE FIRE WARNINGS CEASED. THEY WERE FOLLOWED BY AN APU FAULT MESSAGE. WE RAN THE APU FAULT QRH PROC AND THE MESSAGE EXTINGUISHED. THE FLT LANDED WITHOUT ANY FURTHER INCIDENT. UPON ARRIVING AT THE GATE, MAINT WAS CONTACTED. I EXPLAINED TO MAINT VIA RADIO THAT WE HAD AN APU DOOR INHIBIT MESSAGE AND THAT I WANTED TO SPEAK TO A MECH DUE TO THE NATURE OF THE SEQUENCE OF EVENTS THAT TOOK PLACE. WHEN THE MECH ARRIVED, HE RESET THE APU ECU AND RESTARTED THE APU WITHOUT ANY PROBS AND THE APU RAN NORMALLY. UPON CONSULTATION WITH THE MECH, THE EVENT WAS WRITTEN UP AND ENTERED INTO THE MAINT LOG AS AN APU DOOR INHIBIT MESSAGE DURING FLT. ON REVIEW OF COMPANY OPS MANUAL, THE COMPANY REQUIRES ANY FALSE FIRE MESSAGE TO BE WRITTEN UP AND ENTERED INTO THE MAINT LOG. AN IRREGULAR OPS RPT WAS SUBMITTED TO THE COMPANY EXPLAINING THE SIT AND WRITE-UP.

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.