Airbus Fire Push Button

[westinghouse]

hello again,

if one was to abort the take off due to an engine fire and carries out the ecam, would the fire p/b be illuminated (if the fire is still present) even when your only on battery power?
and would it be still lit if the batteries are switched off?

thanx

[spannersatcx]

yes

and

yes

The button and squibs have 2 28vDC power supplies one of which is the hot bus the other from 28vDC bus (could be 2 or ESS can't remember). You would probably only get half of the p/b lit up if only on the hot bus.

[westinghouse]

thank you.

[Mäx Reverse]

Maybe you could improve the replies' quality, if you give a little more info how you ended up in these very hypothetical scenario...

Technically speaking:

What you describe as being 'only on battery power' is called LOSS OF ALL GENERATORS on Ground. I assume the A/C is stopped (i.e. speed < 50 Knots) otherwise you woulnd't be doing fire procedures.

In this case only the following busses are powered: HOT BUS 1/2, DC BAT BUS, DC ESS BUS.

FWC1 ist powered by the AC ESS BUS. Unfortunately the AC ESS BUS is not powered in the above scenario, so without any FWC working, I doubt there will be any fire indication in the Fire P/Bs. If I remeber correctly from the Box, the Eng Fire Lights in the Centre Pedestal would be working.

An Engine Fire with all Generators is a bit remote, but why are you asking about this scenario with batteries switched off?


@ spannersatcx: Any mention on the power source for the fire P/Bs in the FCOM? Couldn't find one...

Regards, MAX

[westinghouse]

all right ill explain.

i went for my sim recurrency abt a month ago and one of the exercises we practice is and engine fire before V1 on the take off which involves a reject. on coming to a stop the ecam will be carried out and since the fire continues to burn the aircraft has to be evacuated. ( fire pb remains illuminated).
on the ecam it states to swith off all engine masters if the fire continues. since we do not use apu bleed for the take off (company SOP) it reverts to battery power.
whats happened in the sim was after completing the ecam and only on battery power the fire light was not illuminated. which techincally means the fire is out. how ever the evacuation was carried out as a precautionary measure.
in real life would the fire have been present or not is my question.
ie when your only on battery power. acft completely stopped. fire pushbutton pushed. bottles discharged and your engine is still on fire.

hope this info will be helpfull.
thanx.

[mono]

If you are on batt power only on the ground then yes. The light WILL be illuminated if the fire is still present.

However unlike the Boeing there will be no audible warning, just the light.

The lights are powered by the battery bus but the audio circuits by the ESS bus

As has been said only half the integral lights will light up.

[spannersatcx]

Max no idea as I don't have acess to them just maintenance manuals and memory I'm afraid.

[FlightDetent]

so without any FWC working, I doubt there will be any fire indication in the Fire P/Bs. I do not have the books at hand, but seem to remember dual FWC fail procedure to MONITOR OVHD PANEL. Could it be that OVHD indications do not rely on FWC but display hard-wired information from the associated sensors, so that the P/B will remain on?

[mike wess]

It will remain on with no oral warning (if it hasn't been silenced already); However as far as I remember there will be no indication of fire with batteries switched off.