Shut down engine after fire warning msg disappears ?
 

Engine fire warning came out, boeing pilots will shutt down the engine and pull out the fire extinguisher selector then wacth if the msg dispear, this is the sop. But some fellows think if the fire msg dispear after thrust idle , they would not need to shutt down! I will definitely follow the sop, but question is why we still have to shutt down after msg gone? What is the sop for airbus in this case? Thanks a lot!

A fire warning that extinguishes when the thrust lever is reduced to idle is most likely a hot-spot bleed leak onto the fire detection elements. Maybe depending on the location of a bleed leak (downstream of a valve that could isolate it) then maybe it could be shut-off and normal thrust restored (subject to anti-ice requirements of course)

Flightmech

so you mean you won't shutt down in this case?

Hi wingtip777,

If I received an Eng Fire warning, then I'd shut it down.
If I was really struggling for performance (suppose the warning was on the second engine to be shut down), then I'd try as Flightmech suggests.

on the bae146 we had a procedure for exact this situation . when fire warning was triggered- thrust lever idle and fire handle to the first detent what automatically cuts the bleed air. when fire warning goes off then do not shut but try to restore power. when fire warning stays off , then bleed air of this engine off , pull fire handle in again, monitor and land as soon as practicable.

when fire warning stays on or comes on again after power input fire handle to the second detent which shuts the engine. then turn left and or right to fire left , right or both bottles.

for aircraft which do not have this procedure it may be a good idea to try to cut bleed air ( of course only when no real fire is visible) before finally shut it down and fire the bottle.

In a Boeing, the response to an Engine Fire Warning is to carry out the associated memory Items.

The earliest they can be considered complete is after pulling the Engine fire Switch. IF the warning is extinguished at that point, they may be considered complete.

I therefore cordial disagree with Flightmech- It would be totally against SOPs to try and keep the engine running.

So you don't shut it down cause, hell, its probably just bleed air blowing over and if you do shut it down, think of all the paperwork you have to do and all that nasty inconvenience of landing right away.
Or maybe that little fire just ate through the wiring harness and she's just burning like a blowtorch but you can't see it.
The SOP is there for a reason, a really good one. Or maybe you just want to throttle back and think about it for a while and see what happens:= :ugh:

I'm from maintenance and not a pilot so appreciate I have no justified input. If I was one then I would follow the QRH and do what it tells me. That way I'd probably keep my licence. I was merely suggesting why there could be some differences regarding the OPs question. Aerobat77 has highlighted one already, it depends what your SOPs are:rolleyes:

A satisfactory fire/ovht test would prove harness/system integrity.

Over the years engine fire drills have moved from ending the procedure when the fire warning ceases, to always completing the drill including firing the first bottle regardless of when the warning ceased.

Progress or dumbing down?

I like to think that most SOP's have evolved due to experience or lesson learned. If the fire goes out during the drill and the full procedure is not carried out, isn't it the same as just pulling back the throttle lever to see what happens? When we complete the drill and do the checklist, it's called securing the engine. We can let the mechanic and or TSB figure out what happened to it after we land. Our duty is to get to the hotel in one piece and have our just deserved beer.:ok:

It certainly takes some of the thinking and decision making out of the process. Some responsibility too, I suppose.

Abso-flippin'-lutely you shut it down! Do not even consider keeping it running!

You have no way to know whether it was hot air or fire that triggered the warning, if you leave it running just because the light went out when you throttled back, you could be entering a world of hurt.

- my experience is 737 - can you clarify what you use to 'shut down the engine' before you 'pull out the fire extinguisher selector' and what that selector is. It is obviously different.

Fuel lever is an instant shutdown (solenoid valve closes on fuel control as with normal start/stop) Pulling the fire handle/switch first isn't in most cases as engine will continue to run for a little longer until it has burnt the fuel between the spar valve and fuel control.

Pulling the engine fire switch arms the fire bottle, trips the generator, closes the engine fuel valve, closes the bleed.
The drill on the 747 is to close the thrust lever, select the fuel switch to off and the pull the engine fire switch, etc. If the fire light goes out immediately upon pulling the switch do not fire the bottle. If the light remains illuminated after pulling the switch then let her have it.

err - are either of you 'wingtip'?:ugh:

No, sorry:( (It was a case of RTFQ!)

1. Immediate actions

2. QRH


:ok:

Still waiting for our '777 pilot' to respond................

"question is why we still have to shutt down after msg gone?"
Answer is: Because you may still have a fire that is just not triggering the fire loops... and/or, you may still be feeding a fire/potential fire by way of a fuel leak.... you have no way to know from the cockpit. please shut her down, pull the fire handle and blow at least one bottle!

Thanks mate.

Doing so and finding out later it wasn't necessary will be a lot easier to explain after the fact, than not doing so and finding out it was necessary.