737 fire handle - reset in flight?

[David Horn]

If an engine fire handle in a 737-400 is pulled (but not turned), can it be reset in flight to attempt a restart, or is it strictly a one-way system?

Thanks,

Dave.

[f777k]

Hi Dave,

it is possible to push in the Fire Handle. Nothing is latched.
All the Shutoff Valves (Fuel, Hydraulic, Bleed) move to open.
Restart of the Engine is Possible.

so long
Frank

[BelArgUSA]

Hola David -
xxx
Typical Boeing fire handle - shut down fuel, hydraulic, bleed air, electrical...
As a matter of fact think of this. In flight, your CFM-56 windmills.
Not too good for that engine driven hydraulic pump. They are expensive.
Maybe a good idea, to let some fluid "lubricate the pump" from time to time.
All that depends on the reason why you pulled the handle.
On the ground, in 747, we occasionally shut down the engines with these.
To see... if they work. Sometimes maintenance requests us to check them.
Some fuel valves sometimes fail to close, and engine runs on, and on, and on.
xxx
Brgds/
:ok:
Happy contrails

[18-Wheeler]

On the ground, in 747, we occasionally shut down the engines with these.
To see... if they work.

Often an excellent idea - With the mob I used to work for, that was tried on one of the 747's on engine #1. After twenty seconds or so at idle power (most people don't know it takes that long at idle after you pull the handle to get shutdown) the #2 engine quietly shut-down, with #1 still running away nicely.
Oh joy ..... :)

[john_tullamarine]

the #2 engine quietly shut-down, with #1 still running away nicely.

(a) which is why some of us mandate independent inspections for critical engine mx

(b) didn't the operator do operational acceptance checks after significant mx ?

.. red faces.

[Flight Detent]

Not with that 'airline' they didn't..

That incident is but one of several 'they' have been caught out with.

Plus the usual things for these types of operators -

- co-signing independent inspections by the same person.

- doing phantom maintenance at the last moment on items that are about to expire their MEL time limit.

I guess that's a reason for me not going back there after my 'vacation' a couple of years ago!

BTW - Hi 18-Wheeler, how you doin' these days, long time...

Cheers...FD...:)

[rubik101]

Having pulled the fire handle, why would you want to push it in again?
Is it a new procedure you have found somewhere?

[hetfield]

Having pulled the fire handle, why would you want to push it in again?
Is it a new procedure you have found somewhere?

Maybe it was the wrong one......

[gas-chamber]

If you did pull the wrong one, it would be a fair call to reset it, and quick-smart before the boss finds out. Next action would probably be the CVR 'erase' followed by free beers to the co-pilot for the rest of his career.

But if you ever pull one in anger, DO NOT reset it at intervals in the interests of lubricating fuel pumps etc. unless you have a QRH that tells you to do that. I have yet to see one that does. If the problem was serious enough to shut the engine down, don't even think about a relight unless the other one develops a worse problem. Attempting to relight a cold-soaked engine could be a lot more costly than a seized fuel pump. Don't get creative.

[Swedish Steve]

After twenty seconds or so at idle power (most people don't know it takes that long at idle after you pull the handle to get shutdown)
On the B777, the fire handle closes the HP valve as well, so its like a normal shutdown.

On the BA Tristar there was a MEL item that had you pulling the fire handle on every shutdown. I believe it was with APU Bleed air inop. You shut down Nbr 3 eng on the fire handle, and maint then chkd that the HPSOV was closed when you reset it. Yes it took about a minute to shut down on the fire handle.

[BelArgUSA]

Blind execution of procedures published in QRH...
xxx
The Q in QRH means "quick" (and dirty) solving of emergencies or malfunctions which require later reading and following further notes found in expanded check-lists in AOMs. Then, there is what is taught (or used to be taught before the days of modern worthless CBT programs) in classrooms.
xxx
Such attitude "I follow QRH - that is it - no more - check list completed" lead into the disaster of ELAL 747 cargo in Amsterdam by stalling the airplane because of extension of leading edge flaps on one side of the airraft, the other wing's leading edge being disabled, "as per QRH"... which Boeing quickly corrected after the accident.
xxx
I will give you gentlemen an example. You are familiar with the Boeing engine fire procedure. The tune of the procedure is silence the bell, pull the handle, shutting down the engine, then activate a fire extinguisher. If the "red light" goes out - you stop there. If the "red light" does not go out, 30 seconds later, discharge the second fire extinguisher. Agreed...? That is the end of the QRH procedure.
xxx
The crews I trained and briefed in my classroom and simulators learned a further step, not published on any QRH. After "red light" is out 30 seconds later, test your fire detection system, light and bell, again for that engine. There is a slight possibility that your detection system burned out and got disabled by the engine fire and resulting severe damage. There might still be a raging fire there on your engine, despite the red light being "out"...
xxx
You see, in Pprune, there are student pilots, and (highly) qualified line captains, some of which are/were TRE/TRI or training managers. So "stick to your QRH" and do not use your brains. This old dog can still teach tricks you would be surprised to learn.
xxx
:E
Happy contrails

[Mach E Avelli]

Testing the fire system after a fire drill is one I teach as well. I have practical experience of just the very situation where the fire loop got taken out when a combustion can on a RR Dart blew and caused the fire warning to go away before the fire was out.
But like GC, I would not condone 'creative' departures from the QRH just for the sake of it. Not all pilots are particularly knowledgeable of systems and so the QRH is written for the lowest common denominator for good reason. It is when the situation is NOT covered by the QRH that one must use common sense and airmanship and whatever other resources are at hand. But in today's litigious society it would be a brave pilot that stepped outside SOPs and QRHs etc without compelling reason.

[ford cortina]

Both BelArgUSA and Mach E Avelli ( great name btw:ok::ok::ok:) speak lots of common sense.
I am a late 30's FO, aviation is my second career, fast learning about the 737, I get to fly Classic and NG, I always read with interst what BelArg USA, has to say, you should write a book!!!!

[mutley320]

I believe the fire handle will trip the generator cb and gene control relay cb.

[LeftHeadingNorth]

The QRH is a tool that should be used in non-normal situations. Going against the QRH is a bad idea unless you are absolutely sure that you know what you are doing. It is written in blood.... Testing the fire system sounds like a good idea but I wouldn't do it myself since I don't have suffiicient technical knowledge about the fire system. As far as I'm concerned the fire test could just as well be disabled after turning the handle for that particular engine.

Being creative can be a good idea but there are plenty of more accidents when people have been creative than when they haven't. Furthermore, you need to be able to back up your actions in a court of law...

Naturally, the QRH doesn't cover all possible problems and it says clearly in the beginning of it. But being creative in an already serious situation that is uncalled for can prove devistating...

[BelArgUSA]

Some of you here do not have "sufficient technical knowledge". Well, thanks.
Confirms poor opinion I have of XXIst Century training product of graduates of 14 ATPL exams.
No wonder I rather take trains or rent cars in your part of the world.
xxx
In the good old days, we had 120 hours of initial classroom type training.
Systems knowledge, manuals study, procedures, performance.
Then simulator training, two weeks, then line training...
And many of us spent a few years as flight engineer before being pilot.
And often, many "this is not in the books" - "how would you troubleshoot this"...?
xxx
What do you do in initial and recurrent training...? Country club style...?
Cup of tea with biscuits, Earl Grey, certainly, in a cute little cup.
And AOM replaced by the Daily Mirror, with Flight Int'l to seek better jobs...?
Suggest improving your knowledge of airplane systems by reading Pprune.
It is available on the net - www.pprune.org - for free.
xxx
:(
Happy contrails

[18-Wheeler]

I quite agree, BelArgUSA.
For example recently I started a course on the A330 and much to my surprise there was hardly any information on the engines.
They were treated as a 'thing' that hung off the wings, and either they worked or they didn't - With checklists to suit both states.

I like everything I can about every part of the aeroplane.

[BelArgUSA]

18-Wheeler -
xxx
At times, I do not know if I should cry or laugh at what I read here...
I recall my purgatory (or inferno) of my first F/E 727 oral exam. - 1969.
Started day 1, at 09:00, lunch break 12:30-13:30. Finished evening at 17:00.
Day 2 was 09:00 again, completed oral at 12:30, was "lunch time".
Typical question - how many cycles per minute toilet flush operates...?
xxx
Did they tell you how many engines are installed on the A-330...?
Your exam question will be "how do they operate...?
Answer "B" - Good...
xxx
Brgds -
:eek:
Happy contrails

[AKAFresh]

I have read this thread with great interest and I totally understand and respect where BelArgUSA is coming from...

BUT... it is a VERY dangerous area that you go into regarding 'Troubleshooting and being creative'. (I'm not specifically talking about the fire test post engine fire for the B737 I'm just talking in general).

I cant but help think you are a very experienced pilot but there are many pilots with far less experience than yourself here reading these posts. Troubleshooting is one thing but not sticking to the 'Emergency Checklist' is something totally different and if for whatever reason right or wrong, you will have to explain your actions... I would not recommend it to anyone!

Granted many pilots don't have the greatest technical knowledge of their aeroplanes but the emergency checklist/aircraft procedures have been thought through by many people (designers, engineers, pilots etc) and there are reasons why you do certain actions and particularly why you do them in a specific order.

Doing things out of order or getting creative without the 'approval' of the airline and manufacturers procedures, well your asking for trouble which may ultimately get you fired or worse case lead to an accident.

At the end of the day the pilot is not there to trouble shoot (I say this with a pinch of salt) like a flight engineer would per say. Back in the day aircraft and there systems were different and had different levels of reliability... there were many cases of what you speak of 'Not in the books tips and tricks' to solve a situation/problem and thats why many of us always preferred having 3 pilots and having the experience and technical knowledge of the flight engineer with us.

Times have changed with the improved reliability of a/c, 2 man flight deck, better systems and maintenance along with better crm practices, pilot training. The whole industry is learning and getting better hence why air travel is so safe. We do as we are trained because we are trained well and thats why our industry is the safest.

To finish given a serious situation DO what your trained to do!! This does not mean you stop THINKING! Common sense is always good practice along with airmanship. The time to think about doing things differently to what you were trained or actions not in checklist or against them is ON THE GROUND outside of the aircraft, not in the air.


Happy and safe flying!


Aka.




--------------------------------------

Experience is something you gain 3 seconds after you needed it!

[BigBusDriver]

I teach the 737 for a US Major Airline. Our QRH procedure for Fire/Severe Damage has Immediate Action Items (not memory items) that end with the second bottle discharge, if required. Then the crew is directed to the expanded QRH procedure, where the first step is to test the fire detection system.

[Pugilistic Animus]

AKA Fresh I think he's trying to [forcefully] highlight the vast differences between airmanship and procedures,so Now,...LISTEN TO THAT GENTLEMAN,...HE'S JUST TELLING YOU !!!!:ok:

[Landroger]

Okay, let's get the ritual over. I am not a pilot (Booo!) I'm an Engineer (Hurrah!) I'm not an aeroplane engineer (Boooo!) but I am an engineer on very high tech equipment ( Hur ..... oh, all right then.)

This thread is very interesting from the SLF/Flight Deck Groupie (retired :{) point of view, mainly because of the responses from pilots. Which seem to be largely; 'Does it?' And then a sharp intake of breath followed by; 'Ooo, I wouldn't touch it - the checklist won't let you.'

Reading a forum like this is fascinating stuff, but its a bit like reading Welsh or Hindi - every now and then there's a phrase in English that helps you understand a bit of what is going on. All the rest is in TLA - Three Letter Acronym, but really, I shouldn't be surprised. I expect if you heard me and my mates talking shop, you'd get confused by the TLAs as well.:)

I take it that QRHs are the procedures, chiseled into tablets of stone, that guide you through the admittedly fantastically complicated machine that is a modern airliner. To follow them is divine, you say, but then you say; 'but keep thinking - use common sense'. To which I say Ahmen.

I was startled at the number of pilots on this thread who were clearly a bit surprised when 18Wheeler mentioned it takes about 20 seconds to shut the engine down after pulling the fire handle. Right there is good enough reason to at least push it back sometime, in the simulator, without it being part of an evolution, surely?

Is it not 'thinking and common sense' to know that, and know what happens if you push the thing back without discharging the extinguishers? Quite honestly, I don't think my engineering curiosity could be contained, if the procedure did not expressly forbid me from pushing the fire handle back again - assuming I didn't do it to put out a fire.

Okay, I've bared my soul and await the terrible flames. :eek:

Roger.

[ford cortina]

Mate, the QRH stands for Quick Reference Handbook, written by Lawyers for Lawyers and pilots who are just Dumb, me included:cool:.
Hell the dammed thing states that there are situations where the book will not help you.

[low n' slow]

A proper understanding of the aircraft systems is simply put airmanship.
I teach in Airframes and Systems and that is what I tell my students.
Once airborne you have the weather, and you have the plane and the aerodynamic laws and yourself and a colleauge. Ofcourse, rules of the air must be followed. But when the plane breakes down and is degraded, the rules don't apply anymore. In that case, knowledge is your best friend. Knowing that it takes 20 seconds to shut down an engine with the fire handles may be worth a lot when the time comes.

And knowing which systems affect other systems. In my case on the little Saab, the fuel is heated by prop gearbox oil. If we get a fuel temp low warning, the pilot with no particular interest in systems design may dive into the the checklist for "fuel temp low". In the mean time the prop gear box might fail due to lack of oil (hence lack of heating to the fuel) and this could have been easily averted by looking at the prop oil indicators as an instinctive reaction to the initial fuel temp low warning.

This kind of reaction isn't in any book. It requires an interest in what we are actually doing and an interest in our surroundings.

Bel Arg, you are truly a wealth of knowledge! Thanks for all the good tips and keep them coming!

/LnS

[Starbear]

I believe the fire handle will trip the generator cb and gene control relay cb.I think you may have misunderstood some of the terminology along the way. It is the Genrator Breaker (GB) and Generator Control Relay (GCR) which will be tripped or opened when fire handle is pulled not Circuit Breakers, altough admittedly the circuit will definitely be broken! Point is that GB and GCR will close on fire handle reset, all things being equal.

Another point is that it doesn't in fact matter even if the fire handle had been turned in addition to being pulled, it can still be reset and engine restarted (depending on original fault of course). Turning the handle simply discharges the extinguishant (freon gas) into the areas external to the core. i.e. around all of the accessories which may have caused the fire warning. The detection system does not normally monitor the core (certain exceptions monitor turbine overheats but this is not affected by extinguishers). So no harm is done to the engine core by firing the extinguisher. HOWEVER it is definitely not recommended to attempt to relight an engine which has been shutdown following a fire indication unless a greater danger exists.

Rubik 101 asks Having pulled the fire handle, why would you want to push it in again? See above caveat but I have always maintained that those poor guys in the Kegworth B737 incident would have lit a paraffin lamp if they could find one in the circmstances they found themselves in.

[Landroger]

See above caveat but I have always maintained that those poor guys in the Kegworth B737 incident would have lit a paraffin lamp if they could find one in the circmstances they found themselves in.

I'm sure Kegworth causes the hair on all pilot's necks to stand up, but it has also always given me a particular frisson of rather selfish horror. As an engineer, a life long lover of aeroplanes and an interested SLF, I have a recurring image of sitting in that 737, watching the engine spit out its innards. I know enough about aeroplanes and their engines - if you knew my surname, it might make you smile - that I am certain I would have known that one was not long for active service. My fear is; if I had spoken quietly to the cabin crew and asked them to tell the captain what I had seen ..... would they have believed me or would they have 'not bothered the flight deck in the circumstances'?

Were the crew obliged to land at East Midlands or could they have continued to Belfast? It has always seemed to me that if, at their maximum attained height, they had elected to go on, they would have needed power and thus found out about the genuinely failed engine when it was less critical.

I know 'what if's' are a little pointless, but its the way your mind works.

Roger.

[18-Wheeler]

I was startled at the number of pilots on this thread who were clearly a bit surprised when 18Wheeler mentioned it takes about 20 seconds to shut the engine down after pulling the fire handle. Right there is good enough reason to at least push it back sometime, in the simulator, without it being part of an evolution, surely?


It's the way they're made to work on the 747 Classic. The one in question was a GE CF6-50 powered contraption, (with the reversed wiring being done at a certain Chinese maintenance company, not the company I flew for) and the reason it took so long is because they are really intended to be used in-flight, where the fuel-flow is far higher and so they will run out of fuel much faster than they would at idle. As mentioned in another post, other aeroplanes have slightly different systems, such as the 777 which has another shutoff valve closer to the engine so it shuts down much faster - the negative side of that is that the fuel line from the wing down to the engine still has fuel in it.

[Capt. Inop]

737 fire handle - reset in flight?

Nope, gotta have them ground engineers doing it while aircraft is parked on the ground.
Classsic and NG that be. :ok:

[arba]

quote : "After "red light" is out 30 seconds later, test your fire detection system, light and bell, again for that engine. "

in my present SOP, it is not my "switch" anymore at preflight, certainly not in flight !

[Exaviator]

If an engine fire handle in a 737-400 is pulled (but not turned), can it be reset in flight to attempt a restart, or is it strictly a one-way system?

Thanks,

Aircraft systems wise the simple answer to your question is "YES" the handle can be re-set in flight, and assuming there is no damage to the engine it can be re-started. Once the engine has started the tripped generator can also be brought back on line. (I have personally demonstrated this in flight)

As to why, and if you would do it is an operational decision and would depend entirely on the circumstances at the time. :cool:

[18-Wheeler]

Sorta on-topic - What happened with the BMI Kegworth 737-400 when they shut down the RH engine? They tried a restart so it would seem that they didn't turn the handle ... ?

[Rainboe]

Capt Inop
Nope, gotta have them ground engineers doing it while aircraft is parked on the ground.
Classsic and NG that be.
Explain please? You are suggesting G/Es have to reset a fire handle on the ground? Where did you get this? Are you mixed up with CSD disconnect?

[A37575]

Typical question - how many cycles per minute toilet flush operates...?


Which is precisely why this sort of examination was quite superfluous and useless knowledge. I had the same crap on DC3's - knowledge of the torque strength of the rudder and trim cables - all by engineers who delighted in looking down at new pilots with scorn. Best thing that ever happened was to throw away this so called "chalk and talk" in favour of need to know as against nice to know. Hence computer based training for aircraft systems. Nothing wrong with pilots seeking out extra information to their hearts content - although it was not necessary for the purpose of flying the aircraft safely. It was the trouble-shooting experts on the ground and in the air that resulted in the death of all aboard the MD80 that had the stabiliser jack-screw defect.

[lomapaseo]

Sorta on-topic - What happened with the BMI Kegworth 737-400 when they shut down the RH engine? They tried a restart so it would seem that they didn't turn the handle ... ?

Time to get the report out and review it :)

Timing and conditions of a restart attempt are critical. Too little time and too little speed doom the attempt. If they had realized soon after they shutdown the wrong engine then a restart attempt would have been successful on the good engine. But since the flight conditions were such to keep the bad engine docile (vibs went away) they didn't realize their mistake until they spooled the bad engine way up for landing and trashed it. By then there was too little time and airspeed to restart the good engine. I don't believe that the fire handles entered into this until they trashed the bad engine during landing, but the details are in the report.

[BelArgUSA]

My apologies here, for getting "high blood pressure" with some of you, when I am facing the sad state of oversimplification by "modern initial training and system knowledge" as some of you receive with your airlines. Although a line pilot, I got involved with all phases of pilot training, from aircraft systems or performance, to CPT procedures, simulators and line training of both pilot and flight engineers. And I got excellent training myself, not only from PanAm, my original airline, but also with other operators for which I provided contract training in various parts of the world. When I gave an oral exam to a newly qualified on an aircraft type, I always included these "nice to know" questions even if not published, or part of our SOPs.
xxx
None of the "techniques" I mention, or discuss, are meant to deviate from your SOPs, nor were "invented" by me, but are the result of years of training and research, and comparison of procedures adopted by other airlines. The training staff of airlines often get together with other instructors within the airline, or other airlines, or even the manufacturer (Boeing for me) to improve flight safety and reliability of the airplanes we operate.
xxx
I owe my knoweldge to numerous captains and engineers that I flew with during my many years - 1969 to 2008 - that is 39 years, with airlines. All I do here is pass along to those of you who want to know, the "how and why" of airplane everyday operations, that I learned myself from experienced aircrews from many airlines and many nations. Again - none of my recommendations are against your SOPs, they are merely "techniques".
xxx
An anecdote, to give you an idea, of a situation I faced a few years ago.
xxx
An airline (aircraft type is irrelevant) had a procedure where the engine normal ground start was performed with ignition on "both A and B" systems (or ignition "1" and "2" selected together). Fine and dandy. I had learned otherwise with PanAm, where we selected one ignition system only for start. I was training the crews on contract, and had an argument with their chief instructor (in a simulator) as I "deviated from their SOP" which called for both ignition to be selected "to get a better start"... The issue was brought to the chief pilot, and got accused to deviate from SOPs. I explained my position to the chief pilot.
xxx
The selection of one or the other ignition system is aimed at troubleshooting potential system failures (failed igniters, or ignition systems) prior to a flight. Suppose you fly in turbulence, and due to ignition time limitations, you select one system for a few minutes, then the other in turn. How do you know that "the other system works properly"... If you start engines with "both ON" you would never know, would you...?
xxx
Obviously, that airline tried to avoid dispatch delays (the decision of the management, not the pilots), to be sure that the planes "go on time". Of course, if you flame-out an engine in turbulence, is not the problem of accountants, it is a pilot problem... and flight safety.
xxx
So, I made my point to the chief pilot, who agreed with me, and also agreed to let me teach the technique of "single ignition start" and.. later, their SOP was even changed to reflect that technique, which became a normal "procedure" for them.
xxx
For the last 10 years, I was a training manager, and was the final authority as to change procedures... Since my retirement, I have been replaced by CBT, DVDs and computers. I see new editions of FCTMs and other manuals reduced from 600 pages, 2 volumes, to 150 page and thin binder. Saves on weight, paper and rain forests. Even though in my rocking chair since November, I constantly receive calls for training issues or recommendations... for free. Sounds like they miss me... If you dislike my recommendations, or you claim they are conflicting with your airline's SOPs (they know better than me), just ignore my recommendations, you receive their paycheck, not me. I just try to help you all, not to become one of the aviation statistics...
xxx
Again with my apologies, and best regards -
:ok:
Happy contrails

[Capt. Inop]

Explain please?

Will do, simply if you pull the fire handle in flight on a B737 you are not
gonna restart that engine again on that flight.
That's the reason why i never shut down an engine that can push it's own weight within the flight envelope, egt, wibs and even running at flight idle it's gonna provide me with hydraulics and electrics.:cool:

[Rainboe]

Well if the greater need arises, you should be aware that resetting the fire handle will allow normal access for restart, not as the impression you gave that it needs to be reset on the ground.

[Navigator33]

It's the way they're made to work on the 747 Classic. The one in question was a GE CF6-50 powered contraption, (with the reversed wiring being done at a certain Chinese maintenance company, not the company I flew for) and the reason it took so long is because they are really intended to be used in-flight, where the fuel-flow is far higher and so they will run out of fuel much faster than they would at idle. As mentioned in another post, other aeroplanes have slightly different systems, such as the 777 which has another shutoff valve closer to the engine so it shuts down much faster - the negative side of that is that the fuel line from the wing down to the engine still has fuel in it.

Quoting 18-Wheeler.

Just so we don't get confused with the initial airplane (737) the handle (on the 737) will only close the engine fuel shutoff valve. That's why the QRH tells you to shutdown the engine start lever first. If you wouldn't the engine would, indeed, continue to run for another 10 to 20 seconds because of the remainig fuel still present in the fuel system.

[Capt. Inop]

Well mr toxic guy. The way that i understads it you have downgraded from the allmighty B747 to the much simpler 737.

Having flown the Caravelle, the early versions of the DC9, and the very early versions of the B737 vithout a FMC, i'm telling you: Know your systems. And when you do you can come here criticicing me.

[Rainboe]

The only criticism is that you have posted misleading information!
737 fire handle - reset in flight?
Nope, gotta have them ground engineers doing it while aircraft is parked on the ground.
Classsic and NG that be.
Quite wrong. And quite what does what I fly have to do with it? Remove this nonsense and all will be sweetness and light again.

[BigBusDriver]

That's the reason why i never shut down an engine that can push it's own weight within the flight envelope, egt, wibs and even running at flight idle it's gonna provide me with hydraulics and electrics

Never is a big word...

[olster]

guys,the devil is in the detail and pedantic though it may be,Boeing do not refer to a 'fire handle' on the 737 series but an 'engine fire warning switch...'


all the best

[lomapaseo]

Any guesses what happened next....?

Just a guess, having never done this but after 30 secs or so an engine in flight will have spooled down to windmill, but I'm assuming these guys were on the ground (hopefully) so the engines would have spooled way down to zilch. The generators would have cut out as well and supossedly you would be on battery power if they hadn't disabled that as well.

Now if the ignition was still on and they energized the spray (or dribble) function then the fuel would simply dribble to the tailpipe and out on the ground. But if they still had a fair amount of air left in the compressor than the fuel would ignite in the combustor and quickly spread to the fuel dribbling into the tailpipe with a big swoosh, upon which they would put the engine on the starter and pray for rain.

These kind of trials are a whole lot more fun to do in real life than in a simulator since the results have a way of varying from bad to worse :)

[Flight Detent]

Errrr...Olster,

I think you'll find on the 737NG it's now "Engine Fire Switch",

Boeing have dropped the 'warning' for consistency between types.

Cheers...FD...:)

[AeroTech]

Hi guys

Hola BelArgUsa, as usual I enjoy reading your posts even when you was a member in another aviation forum.

Excuse my ignorance, it will be nice if you can give me some clarifications because I didn’t get the point of your “further step” (After "red light" is out 30 seconds later, test your fire detection system, light and bell, again for that engine).
Let say that after this step or procedure the fire detecting system is still intact/operant, do you continue your flight to your destination or do you divert to the nearest/adequate airport?
So I am wondering if it is possible to continue the flight after engine fire on B747 (I assume you are talking about this aircraft).

If the second fire extinguisher bottle is discharged, can this penalize the adjacent operant engine? (I don’t know how many engine fire extinguisher bottles are in B747, may be 2 bottles for each 2 adjacent engines???).

BigBusDriver, what’s the goal of such procedure in B 737 (testing fire detection system after discharging the second bottle).

I guess I am missing something, so please enlighten me.

Thanks
Regards

[RAT 5]

1. Does not the QRH say fire the bottle if the handle is still red after fuel to cutoff? It is not a given, but conditional.

2. Testing the Fire system after completing the QRH is hardly going against the QRH. You have done as told, but then, for your own comfort, done a little extra which would appear not to effect any other system.

3. What I was taught, and pass on with enthusiasm, is "QRH complete" check Recall. There may have been a multiple failure and there are other issues to be addressed. It also tells you the status of the a/c and will help in the review phase of what to do next. "QRH complete" does not end the thinking process, but sadly that is what many seem to think. The classic is "no crew action required", only to find at the next landing the MEL grounds the a/c. Oops; the QRH says nothing about checking MEL in flight, but the C.P. will think it bad captaincy if you park the a/c at the wrong airfield and they have to spend mega bucks getting it home.

There is much the QRH doesn't tell us. It needs to be used with intelligence and common sense and airmanship.

[olster]

f/d -I've just checked in our FCOM and it's still engine fire warning switch -uk ng operator;you could still be right with your company but it definitely isn't fire handle!!

b/rgds

[BelArgUSA]

Aerotech -
xxx
Regarding the engine fire warning light - if you have an engine fire, when the light goes "out" - maybe the light bulb "failed" - or the fire detection loop got burned-out by the fire itself, and the warning light would no longer test. Note that on some airplanes - such as the 747, you have double fire detection loops and double temperature gages which permit perfect monitoring.
xxx
As far as fire protection equipment - freon bottle - some 747 have 2 bottles only per wing (selectable to any of the engines on that wing) or the option of 2 bottles per engine (4 per wing). It is an option. Most 747 have the 2 bottles per engine (and also for the APU in the tail). For education and statistics - most engine fire warnings are bleed air related (overheat) and often "stop" when power is reduced. Other fires are electrical accessories on the engine, such as generator wiring. Some airlines have the policy "engine fire warning, continue engine fire procedure in any and all cases". Some other airlines permit to stop the procedure if the warning goes out (power reduction or power to idle = bleed air).
xxx
There is a "constant fire" inside operating engines...! - And a "tailpipe" engine fire (often on engine starts) cannot be extinguished by discharging a freon bottle. The only thing that you can do in a tailpipe fire situation is to continue to operate the starter motor. If you would operate the fire handle, it would stop bleed air to the starter, and make a tailpipe a worse situation if unable to crank the engine.
xxx
I hope that some "nerds" will have acquired some "system knowledge" here.
xxx
In a 3 or 4 engine airplane, should you have an engine fire, or engine failed, you can continue to your destination. I would, as per company policy, more than aircraft performance capability, recommend landing ASAP after an engine fire. Engine failure... well, that is ok. A BA 747s crossed the Atlantic with an engine out. Since it is BA, nobody will critique their decision. Would it be a US airline, most here would say "bunch of idiots, these Yanks"...!
xxx
:ok:
Happy contrails

[Starbear]

What happened next......

I vaguely recall this incident. Did it not result in 4 simultaneous engine replacements?

[Meikleour]

Scenario that I experienced.

Classic 747 crew with `real` F/E in the cruise for about 40 mins. with the APU shut down normally before take-off.

APU fire warning occurs. F/E tests both fire loops which are OK so order given to fire the APU bottle.

Fire light goes out ................. for about 2 minutes then comes on and stays on!

En-route diversion carried out with fire warning still on until short finals.

Maintenance find that the two fire wire loops which should have been run parallel to each other in the bay have been crossed over! Thus the vibration in flight rubbed the insulation off and gave BOTH a fire warning AND a valid wire continuity check! Sometimes you just can`t outguess bad servicing.

[AeroTech]

Hi,

BelArgUSA, thank you for your post.
I was expecting more details regarding the goal or the utility of your procedure or “further step”.

After reading your posts (11 & 49), I guess your concern is there might be a raging fire in the engine despite the red light is off and discharging 2 bottles and the fire may spread. Hence there is a need for testing the fire detection system to ensure the fire is extinguished.

If you perform a test and you find out the light bulb is good and the fire detection loop is working. Do you still land ASAP?

If you perform a test and you find out either the light bulb or the fire detection loop is not working. Do you still land ASAP?

Per company policy you recommend landing ASAP after engine fire. Do you take in account your procedure of testing engine detection system to decide to land ASAP or not? Or you land ASAP regardless of the result of test?
xxx

BigBusDriver and other pilots who fly twinjet, what’s the goal or the utility of testing fire detection system since you will land ASAP anyway regardless of the result of the test? (after the second bottle is discharged and engine fire light is off)

Feedback appreciated.
Thanks
Regards

[NSEU]

Most modern aircraft have fire handles which shut off the fuel at the engine (FMU, HMU, etc) .... as well as at the fuel spar valve (usually in the wing). These include the 767, 747-400, 767NG, etc. This will result in a very quick shutdown.

I had to pull a 747-400 fire handle as part of a maintenance check last year. I reset the handle, but, at the time, I didn't realise that I would have to manually reset the associated generator field breaker (by cycling the GCB switches). Perhaps this is what ASFKAP refers to? Loss of all main bus power?

Rgds.
NSEU

[BigBusDriver]

I should clarify our procedure. It's not only done after the second bottle is discharged, but after the fire light extinguishes, whether that is after one or two bottles.

The utility of testing the integrity of the system is obviously to confirm that the light is out because the system is not longer detecting a fire, as opposed to a problem in the fire detection. If everything works as advertised a FAULT light should give an indication of a problem in the detection system, but in the case of a real raging fire, who knows what's going on out there.

Again, after any fire event the crew are going to proceed to the nearest suitable airport and put the thing on the ground, but how the crew handle that divert may be different depending on whether they have a secured engine or a fire that cant be contained.

[AeroTech]

Hi,

It seems that 747 are fitted with double fire detection loops and double temperature gages which permit engine monitoring in case of engine fire.

Are temperature gages basic or optional items on 747.

Are fire detection loops for detecting overheat and fire (as in some aircraft) or only for detecting engine fire?

Are you required to shutdown engine if the gage temperature reaches certain limit?

Are there other aircraft that are fitted with temperature gage to detect engine overheat/fire?

It will be nice if someone can post the complete procedure of engine fire for companies that require testing the engine fire system after the fire light extinguishes and after discharging one or two bottles (aircraft with 2, 3, or 4 engines).

Thank you for your feedback
Regards.

[Rainboe]

In no Boeing Engine Fire checklist that I know (737,747,757) is one required to check the fire warning system after discharging an extinguisher following a fire. Not required, not recommended and not done. Period. Our 747s did not have engine temperature gauges other than EGT and oil temperature. Only firewires.

[Swedish Steve]

It seems that 747 are fitted with double fire detection loops and double temperature gages which permit engine monitoring in case of engine fire.

Are temperature gages basic or optional items on 747.

Can you tell us what you are talking about. Do you mean a temp gauge driven by the fire loop? Never heard of that. Definitely not on the B744, is it something that was on some B742s? Where are the indicators?

[Exaviator]

Steve,

The Classic range of B-747s had individual engine nacelle temperature indicators which were in addition to the actual fire warning system. The follow up procedure following a fire warning and discharging one or both fire extinguishers as applicable was to check the Nacelle Temperature Indicator.

A reading above 7 units was a good indication that the engine fire had not been extinguished.

There was also a "Fault Light", which indicated a failure of one or both fire detection loops. A fault in both loops was also treated as a fire.

Does that help? Cheers.

[CHfour]

ASFKAP,

I'm fairly sure your QRH won't tell you to pull the fire handle for a high nacelle temperature.....

In case of an overheat light, the QRH says reduce thrust until the light goes out and operate at the reduced thrust. If light remains on, carry out "engine fire, severe damage, separation" drill. This does require you to pull the fire switch . If the light is still on you activate the extinguisher.

[BelArgUSA]

Boeing AOM page 12.20.01

ENGINE NACELLE OVERHEAT
A nacelle temperature indication between 2.5 and 7.0 (amber range) should be monitored closely. NOTE A maintenance log entry should be made if nacelle temperatures stabilize in the anmber range or of A and B indicators do not agree within 2.5 units in the amber range.

IF NACELLE TEMPERATURE INDICATION IS APPROACHING 7.0 (RED):
Bleed Air Valve Switch... CLOSE
- Check VALVE CLOSE light illuminated.
Fuel Heat Switch... CLOSE
- Check OPEN light extinguished.
Nacelle Anti-Ice Switch... OFF
- Check VALVE OPEN light extinguished.
Engine Trust Lever... RETARD TO IDLE
- If nacelle temperature indication continue to rise, shut down engine.
See Chapter 2. INFLIGHT ENG FAILURE/SHUTDOWN

NACELLE FIRE DETECTION/FAULT LIGHT ILLUMINATED
Nacelle Temperature Indicators... CHECK.
- Identify engine and detector indicating in "red band"
Nacelle Fire Detector Switch... POSITION TO UNAFFECTED DETECTOR
- FIRE DETECTION and FAULT lights should extinguish.
Nacelle FIRE/FAULT Test Switch (Unaffected Detector) POS TO FIRE then FAULT.
- Position Test Switch of unaffected detector switch FIRE then to FAULT and check nacelle temperature indicator in the "red band" for FIRE TEST and for FAULT TEST. Fire warnings should occur in both positions.
- If unaffected detector test is normal, leave Detector Switch as position and continue normal engine operation.
- If unaffected detector does not test normally, position Detector Switch to the detector indicating in the "red band" and accomplish ENG FIRE SEVERE DAMAGE/SEPARATION checklist (Chapter 2 AOM or QRH)

Boeing AOM Page 12.50.01- 747-200/300 JT9D-7Q
Fire Protection Supplementary Information
Engines
Two engine fire detector systems are installed for each engine. Each system provides both relative temperature level indication and fault or fire detection capability and may be operated independently of the other.
xxx
For normal operations, both detector systems are required to indicate a fire warning. A fault in both detector systems will result in a fire warning and during single detector system operation, either a fault or a fire will result in a fire warning.
xxx
If an electrical short occurs, the affected nacelle temperature indicator will be locked in the "red band" and the necelle fire detector fault lights will illuminate. Selecting the operative detector system will extinguish the fault lights.
xxx
A detector open will NOT affect the operation of the detector system but will be evidenced by NO response to the fire test.
xxx
The fire detector system will respond to the following indications and warnings:
- Master FIRE warning lights will illuminate.
- Fire warning bell will sound.
- Engine FIRE switch will illuminate and remein illuminated as long as fire exists.
- Nacelle temperature indicator will be in "red band" and remein as long as fire exists.
NOTE
The fire warning will be locked on if an electrical short occurs during a fire. Selecting the operative detector will allow the warning indication to cease when the fire condition has passed.
xxx
Each engine has two fire extinguishing bottles which may be discharged separately into the nacelle area. Two nacelle discharge indicators, one for each extinguisher bottle, are located on the RH side of the engine strut. An indicator, when not intact, indicates that the associated bottle has been thermally discharged as well.
xxx
(end of Boeing AOM text)
:ok:
Happy contrails

[kniloc]

Engine Trust Lever... RETARD TO IDLE
- If nacelle temperature indication continue to rise, **** down engine.


Does this work?;)

[BelArgUSA]

Apologies -
Fat fingers when aiming for "U" key but getting a "I"...
Or shall I claim an earthquake moving my keyboard as I was typing...?
Other excuse - my cat was observing my poor spelling and stepped on key.
:suspect:
Happy contrails