A B757 first officer heard and saw the APU fire warning in the nose wheel well during his exterior p...

Narrative:

During the preflight walk around; as I was walking away from the nose gear and towards the right engine; I heard the APU fire warning. I turned back to the nose gear and saw the APU fire warning light flashing. I quickly re-approached the nose gear and confirmed that it was the APU fire warning light and aural. I pushed the APU shutdown button and then pushed the APU fire extinguisher button. I then quickly returned to the airplane to tell the captain what I had did. It was during this conversation that he told me he was testing the aircraft's fire system and I had reacted to a fire test. I've been doing walk arounds for over 10 years and not once; have I ever heard the APU fire warning. Also; during a proficiency check; I was asked about what actions I would take if the APU fire warning sounded during a walk around. We even spent time discussing if the nose gear strut was covered in crud and I couldn't read the labels; what button does what and which to push first and second. I also now realize that if this was to happen again; what will I do? Do I run back up to the cockpit to verify the fire; and by doing so waste precious time if there is a fire or do I assume the worst-case scenario. I will definitely be asking the captain; from now on; to hold off on his fire test until I return from the walk around.

Original NASA ASRS Text

Title: A B757 First Officer heard and saw the APU fire warning in the nose wheel well during his exterior preflight walk around and discharged the fire extinguisher. The Captain was simultaneously performing a preflight fire detection test.

Narrative: During the preflight walk around; as I was walking away from the nose gear and towards the right engine; I heard the APU fire warning. I turned back to the nose gear and saw the APU fire warning light flashing. I quickly re-approached the nose gear and confirmed that it was the APU fire warning light and aural. I pushed the APU shutdown button and then pushed the APU fire extinguisher button. I then quickly returned to the airplane to tell the Captain what I had did. It was during this conversation that he told me he was testing the aircraft's fire system and I had reacted to a fire test. I've been doing walk arounds for over 10 years and not once; have I ever heard the APU fire warning. Also; during a proficiency check; I was asked about what actions I would take if the APU fire warning sounded during a walk around. We even spent time discussing if the nose gear strut was covered in crud and I couldn't read the labels; what button does what and which to push first and second. I also now realize that if this was to happen again; what will I do? Do I run back up to the cockpit to verify the fire; and by doing so waste precious time if there is a fire or do I assume the worst-case scenario. I will definitely be asking the Captain; from now on; to hold off on his fire test until I return from the walk around.

Data retrieved from NASA's ASRS site as of April 2012 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.

Attributes
ACN	836753
Time
Date	200905
Local Time Of Day	0601-1200
Aircraft 1
Make Model Name	B757-200
Flight Phase	Parked
Component
Aircraft Component	APU Fire Extinguishing
Person 1
Function	Pilot Not Flying
Experience	Flight Crew Last 90 Days 190 Flight Crew Total 10000 Flight Crew Type 4000
Person 2
Function	Captain
Experience	Flight Crew Last 90 Days 170 Flight Crew Total 17000 Flight Crew Type 9000
Events
Anomaly	Deviation - Procedural Published Material / Policy

A B757 first officer heard and saw the APU fire warning in the nose wheel well during his exterior preflight walk around and discharged the fire extinguisher. The captain was simultaneously performing a preflight fire detection test.