B737-300 captain points out the after market addition of a cargo fire warning and suppression system...

Narrative:

Cargo fire warning/suppression system B737-300. The event happened in a simulator, and is submitted to highlight a problem with a critical aircraft system panel location and warning function. During a recent proficiency training, we were given a fire warning bell/light situation on rotation. I was in the right set and silenced the bell. As we continued the climb, I could see no lights on the fire/overheat panel, and tested the system. Nothing came on, and we assumed it was a false warning to get us to reject at or above V1. Shortly we got a call from the 'flight attendant' saying the floor in the aft cabin attendant was hot. Immediately we both looked to the upper left corner of the forward overhead panel and saw the aft cargo fire light on. Feeling stupid, we got out the QRH and followed the procedure. Later, I asked several instructors about the malfunction, and they indicated most pilots look down, assume it was false, and press on. For yrs we have been trained and conditioned to look down. The cargo fire detection uses the same bell and glare shield light as does the engine fire warning system, and there are no other lights directing attention to the upper left corner of the overhead panel. Once silenced, the bell does not ring again. This is an 'after market' system, and I wonder how much human factors study went into the location and operation of the system. The 700 system is down on the center console and a warning light is hard to miss. Recommendations: a concentrated education program on the system, tendency to silence the bell and then assume it is a false warning. Add a QRH item for 'apparent false fire warnings' that would direct the pilots to look at this panel and then go to the appropriate QRH item. The bell should ring again in 10 seconds if crew action has not taken place. A long term solution is to add a light that is in the pilot's field of view that indicates a cargo fire. Company needs to establish a panel of pilots/human factors experts to look at new equipment, its function, location, and integration with existing systems and procedures.

Original NASA ASRS Text

Title: B737-300 CAPT POINTS OUT THE AFTER MARKET ADDITION OF A CARGO FIRE WARNING AND SUPPRESSION SYSTEM HAS THE FIRE WARNING LIGHT LOCATION NOT ASSOCIATED WITH THE FIRE WARNING PANEL. IT IS NOT EVEN IN THE FIELD OF VIEW OF THE PLTS.

Narrative: CARGO FIRE WARNING/SUPPRESSION SYSTEM B737-300. THE EVENT HAPPENED IN A SIMULATOR, AND IS SUBMITTED TO HIGHLIGHT A PROB WITH A CRITICAL ACFT SYS PANEL LOCATION AND WARNING FUNCTION. DURING A RECENT PROFICIENCY TRAINING, WE WERE GIVEN A FIRE WARNING BELL/LIGHT SIT ON ROTATION. I WAS IN THE R SET AND SILENCED THE BELL. AS WE CONTINUED THE CLB, I COULD SEE NO LIGHTS ON THE FIRE/OVERHEAT PANEL, AND TESTED THE SYS. NOTHING CAME ON, AND WE ASSUMED IT WAS A FALSE WARNING TO GET US TO REJECT AT OR ABOVE V1. SHORTLY WE GOT A CALL FROM THE 'FA' SAYING THE FLOOR IN THE AFT CAB WAS HOT. IMMEDIATELY WE BOTH LOOKED TO THE UPPER LEFT CORNER OF THE FORWARD OVERHEAD PANEL AND SAW THE AFT CARGO FIRE LIGHT ON. FEELING STUPID, WE GOT OUT THE QRH AND FOLLOWED THE PROC. LATER, I ASKED SEVERAL INSTRUCTORS ABOUT THE MALFUNCTION, AND THEY INDICATED MOST PLTS LOOK DOWN, ASSUME IT WAS FALSE, AND PRESS ON. FOR YRS WE HAVE BEEN TRAINED AND CONDITIONED TO LOOK DOWN. THE CARGO FIRE DETECTION USES THE SAME BELL AND GLARE SHIELD LIGHT AS DOES THE ENG FIRE WARNING SYSTEM, AND THERE ARE NO OTHER LIGHTS DIRECTING ATTENTION TO THE UPPER LEFT CORNER OF THE OVERHEAD PANEL. ONCE SILENCED, THE BELL DOES NOT RING AGAIN. THIS IS AN 'AFTER MARKET' SYSTEM, AND I WONDER HOW MUCH HUMAN FACTORS STUDY WENT INTO THE LOCATION AND OP OF THE SYSTEM. THE 700 SYSTEM IS DOWN ON THE CENTER CONSOLE AND A WARNING LIGHT IS HARD TO MISS. RECOMMENDATIONS: A CONCENTRATED EDUCATION PROGRAM ON THE SYSTEM, TENDENCY TO SILENCE THE BELL AND THEN ASSUME IT IS A FALSE WARNING. ADD A QRH ITEM FOR 'APPARENT FALSE FIRE WARNINGS' THAT WOULD DIRECT THE PLTS TO LOOK AT THIS PANEL AND THEN GO TO THE APPROPRIATE QRH ITEM. THE BELL SHOULD RING AGAIN IN 10 SECS IF CREW ACTION HAS NOT TAKEN PLACE. A LONG TERM SOLUTION IS TO ADD A LIGHT THAT IS IN THE PLT'S FIELD OF VIEW THAT INDICATES A CARGO FIRE. COMPANY NEEDS TO ESTABLISH A PANEL OF PLTS/HUMAN FACTORS EXPERTS TO LOOK AT NEW EQUIP, ITS FUNCTION, LOCATION, AND INTEGRATION WITH EXISTING SYSTEMS AND PROCEDURES.

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.

Attributes
ACN	551051
Time
Date	200206
Day	Fri
Local Time Of Day	1201 To 1800
Place
Locale Reference	airport : zzz.airport
State Reference	US
Altitude	agl single value : 0
Aircraft 1
Operator	common carrier : air carrier
Make Model Name	B737-300
Operating Under FAR Part	Part 121
Flight Phase	ground : takeoff roll
Flight Plan	None
Person 1
Affiliation	company : air carrier
Function	flight crew : captain instruction : trainee oversight : pic
Qualification	pilot : atp
Experience	flight time last 90 days : 50 flight time total : 25000 flight time type : 20000
ASRS Report	551051
Person 2
Affiliation	company : air carrier
Function	flight crew : first officer instruction : trainee
Events
Anomaly	aircraft equipment problem : critical other anomaly other
Independent Detector	other flight crewa other flight crewb
Resolutory Action	none taken : detected after the fact other
Consequence	other
Supplementary
Problem Areas	FAA Aircraft Company
Primary Problem	Aircraft

B737-300 captain points out the after market addition of a cargo fire warning and suppression system has the fire warning light location not associated with the fire warning panel. It is not even in the field of view of the pilots.