Shut down engine after fire warning msg disappears ?

[Speedbird48]

Just one more before this one gets put to bed.

The initial warning may destroy or burn up the fire warning loop, therefore you have no clue as to what has happened, so you shut it down.

This has already been seen, and the QRH is written to cover it without reinventing the wheel.

Speedbird 48.

[grounded27]

From the aspect of liability shut it down! Other factors being closest suitable etc. From a logical standpoint if you reduce throttle and the warning goes away, advance and it returns, there is little if no doubt it is a bleed leak, isolate bleed systems and observe. A bleed leak is going to do nothing more than tear up soft materials within the nacelle. Just how much do you want said engine available for landing (altitude,rwy length etc). We all know SOP does not cover the unstandard condition. The engine has a redundant fire detection system.

[misd-agin]

What if it's a small leak and at idle thrust isn't enough to fed, or start, a fire? What if advancing the throttle puts enough fuel through to feed the fire and you think it's just a bleed leak???

Shut it down.

Let the investigators on the ground figure out if this is an "unstandard"(?) situation.

Please don't go making stuff up unless it's really, really, really, really, non standard ops or something that's way outside of expected ops (KSUX DC-10, Scully/Hudson, Delta KSAN L1011 stab failure, 757 dual deep idle stall, etc, etc).

Oh, the DC-10 in KSUX had redundant hydraulic systems. Redundant, just like the dual fire loops.

[grounded27]

misd

Please don't go making stuff up unless it's really, really, really, really, non standard ops or something that's way outside of expected ops (KSUX DC-10, Scully/Hudson, Delta KSAN L1011 stab failure, 757 dual deep idle stall, etc, etc).

Oh, the DC-10 in KSUX had redundant hydraulic systems. Redundant, just like the dual fire loops.

The above failures were clear an evident failures of systems and have nothing to do with a false fire warning due to a bleed leak. I am a young man but have experience with old aircraft. A pilot does not have to be a hero to do some simple non-vital troubleshooting, all the above references were vital. Oh I know the DC-10, hey when you have the luxury of a flight engineer to watch all 3 hyd systems dump beyond his control, well this is a hell of allot more threatening than an engine fire warning. Thinking back I was on an MD-11 with 1 loop out on an engine 2.5 hrs into an 8 hr flight, the 2nd loop failed and we simply returned to base. We all knew we had simply lost reliable indication and understood the consequences.

No need to freak out when bitching Betty comes alive, she deserves respect, a little logic is extremely valuable when situational awareness is key!

[grounded27]

What if it's a small leak and at idle thrust isn't enough to fed, or start, a fire? What if advancing the throttle puts enough fuel through to feed the fire and you think it's just a bleed leak???

Shut it down.

At an attempt to decipher this statement, this sort of engine fire has never happened on a jet engine. Fuel pressure is somewhat constant, none the less given the fact it can vary you would experience a constant fire. Retard thrust, bleed will drastically reduce, fuel will burn hard!

[Old Fella]

To Shut Down Or Not to Shut Down

Every aircraft on which I have operated has had the same immediate actions. If a Fire Warning is illuminated, Shut down the affected engine with the Fire Handle/Switch after confirming Warning and Engine to be shutdown. Why, because the Engine Fire Handle actuates all the appropriate valves and electrical relays to isolate the engine in terms of fuel, hydraulics, bleed air, electrics etc. If the Engine Fire Warning persists after shutting down, fire the first bottle. If the warning extinguishes complete the Clean Up checks as per the Checklist. If the warning persists after firing the first bottle, fire the second. Engine fires are not always able to be seen, so you have to believe that the warning is valid and act accordingly. If you have an uncontrollable fire just pray and fly at a speed which will hopefully blow the fire out. Aircraft manufacturers put a lot of money, time and effort into designing procedures to suit their product. They know what is best I suggest. Follow their published procedures.

[4dogs]

Boeing 717

I am not sure if it has changed recently, but the Boeing 717 fire warning procedure included a 'throttle to flight idle' assessment step - if the light went out, the bleed air was isolated and the engine could continue to be operated at Captain's discretion.

Of course, not "real" Boeing but an interesting philosophical conundrum for a merged entity that wouldn't necessarily call themselves the OEM...

Stay Alive,

[Flightmech]

Just to put the "what if the fire had already burned through the loops" to bed, if this was the case then an EICAS/ECAM/STATUS/ADVISORY etc etc message of some kind would be displayed and a simple fire test would prove integrity (wouldn't it?)

[aerobat77]

and a simple fire test would prove integrity (wouldn't it?)

@ flightmech : that is pretty right.

What if it's a small leak and at idle thrust isn't enough to fed, or start, a fire? What if advancing the throttle puts enough fuel through to feed the fire and you think it's just a bleed leak???

@ misd agin : here you missed again. such a scenario will not happen due to reasons grounded wrote.

in general of course the abnormal checklist is the guideline what to to , it may be aircraft specific.

i always smile when emergencies and procedures are discussed . most the gents here are flying for virtual airlines without a doubt and of course rush in shutting down and train themselfes at engine out situations behind the monitor. the very few ones who are not just hope to never hear the fire bell. shutting down an engine which is not obviously at a real fire or catastrophic failure and produces thrust is a big decision.

especially when in bad weather/ IMC conditions, high gross weights, mountains in the area etc etc. your first thought is to see mother earth in one piece and not what the investigators will say. but thats only understandable for the gents who ever felt how the fear tastes sitting behind the steerings.

best regards

[16024]

On the CRJ there is a Red Light warning for Bleed leaks, but that comes with a "Bleed air duct" aural warning. There's no memory (recall) item, and the QRH leaves you with an idling engine, and no further guidance. (Been there).
On the Boeing, which we mostly seem to be talking about, once you have started into the memory items, you are committed. Why wouldn't you? (Been there, too).
Even if you just get a short warning (lights and/or bell) that goes away before you start the drill, I would think carefully before disregarding it.

[wingtip777]

BOAC
FOR 777， the memory items including cutoff the fuel control switch before pull out the fire switch. pulling out the fire switch is to close the spar valve, i think.

[wingtip777]

Speedbird 48
the 777 QRH says : pull out fire switch, if the msg still shown, release the bottle. that means if the msg gone, we don't have to release the bottles. if the loop is damaged by fire, then this drill is not acceptable, right?

another intersting thing is : the QRH doesn't say what to do if the msg dispear!!???

[lomapaseo]

I was under the impression that if a fire loop is damaged it will annunciate as if it were a fire.

Mechanics on here please set me straight

[misd-agin]

The OP stated that some guys think if the light has gone out they don't have to shut the engine down. That's "making up stuff".

Summary - shut it down, unless some highly unlikely to occur event happened that makes delaying the burning engine shutdown the prudent course of action.

Odds of that exception happening? Small, but it's amazing to watch guys start to run down the "maybe's it's this" trail. early in the trouble shooting.

[BOAC]

Originally Posted by wingtip

pulling out the fire switch is to close the spar valve, i think.

- come on! Are you REALLY a 777 pilot? You "THINK"?? Don't you know? What does it do?

the QRH doesn't say what to do if the msg dispear

- are you sure?

Folks - here we have a 777 'Captain' who in Feb 2010 posted

"HI THERE IS A BOX ON THE ARR CHART OF EHAM, INSIDE THE BOX IS : "clearance limit is artip. " WHAT DOES IT MEAN IN THAT CASE? THANKS A LOT!
ARTIP IS A WAY POINT OF THE ARR AT EHAM."

Answers on a postcard?

[Denti]

Smells like another case of FSX pilot.

Guys, there is nothing wrong asking questions for your simulations (although at some point we need a simulator forum), but make it clear in the beginning that it is sim question.

I would be surprised if the 777 QRH doesn't exactly state what happens in the case the fire warning ceases, i know for sure the 737 does and i would not think the 777 is less sophisticated than the small one.

[Flightmech]

No delay here!

8.1.2
8.1.2 FIRE PROTECTION
B-777 Quick Reference Handbook

[] FIRE ENG L,R
Condition: Fire is detected in the engine

1 A/T ARM switch
(affected side) . . . . .Confirm . . . . . . . . . . . OFF
2 Thrust lever
(affected side) . . . . .Confirm . . . . . . . . . . . Idle
3 FUEL CONTROL switch
(affected side) . . . . .Confirm . . . . . . . . CUTOFF
4 Engine fire switch
(affected side) . . . . .Confirm . . . . . . . . . . . Pull
5 If the FIRE ENG message stays shown:
Engine fire switch . . . . . . . . Rotate to the stop
and hold for 1 second
If after 30 seconds, the FIRE ENG message stays
shown:
Engine fire switch. . . . . . . .Rotate to the
other stop and
hold for 1 second
6 APU selector
(if APU available) . . . . . . . . . . . .START, then ON
7 Transponder mode selector . . . . . . . . . . TA ONLY
8 Plan to land at the nearest suitable airport.
9 Do not accomplish the following checklist:

(Continues)

[grounded27]

Lompasso

I was under the impression that if a fire loop is damaged it will annunciate as if it were a fire.

Mechanics on here please set me straight

We generally have 2 types of loops, the salt type that if damaged will generally open the circuit giving a fault, if center conductor grounded to outer case will gave a fire light indication and normally you need a 2ND loop to give a full warning. "the salt melts and allows for conductivity"

The 2ND and most common type of modern loop relies on gas filled tubes that have pressure switches, high press = fire, low pressure =failure and once again you need both loops to go high pressure to get the full on lights and bells warning.

In my experience 2 failures will not give a fire warning, you understand you now have no way to know if your engine develops a fire and operate by SOP or Captains discretion.

[Meikleour]

grounded27: I have an interesting tale to tell....

situ: 747 Classic in cruise about one hour into the flight when we get a fire warning on the shutdown APU. F/E does a fire test on both loops and confirms that the warning is genuine. Fire bottle discharged and warning ceases ........... for about two minutes and then comes on again continuously! Diversion initiated to nearest airport. Warning was on all the time until about 500ft. on finals when it went out. Landed with fire services in attendance who then confirmed that no fire appeared obvious.

Engineering subsequently discovered that the twin fire loops that should have run in parallel about the APU bay had been fitted so that at one point they crossed over. This led to the insulation being abbraded giving a valid fire warning + a valid continuity check!

Moral to the story? You cant predict everything! There is generally one course of action that is the safest you just have to realise what that is!

[grounded27]

Thanks for the share Meikleour, I fully agree with safety as the best policy. There was no other option but to assume a fire in your situation, especially after the fire appeared to respond to the agent for several minutes.