737 fire handle - reset in flight?
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 !!!!
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What happens if ...... ?
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.
Roger.
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.
Roger.
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Mate, the QRH stands for Quick Reference Handbook, written by Lawyers for Lawyers and pilots who are just Dumb, me included
.
Hell the dammed thing states that there are situations where the book will not help you.
. Hell the dammed thing states that there are situations where the book will not help you.
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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
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
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mutley320
I believe the fire handle will trip the generator cb and gene control relay cb.
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?
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Private fear.
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.
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.
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.
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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 !
in my present SOP, it is not my "switch" anymore at preflight, certainly not in flight !
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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.
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.
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 ... ?
Warning Toxic!
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Capt Inop
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?
Nope, gotta have them ground engineers doing it while aircraft is parked on the ground.
Classsic and NG that be.
Classsic and NG that be.
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Typical question - how many cycles per minute toilet flush operates...?
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 ... ?
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.
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Apologies
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 -
Happy contrails
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 -
Happy contrails
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Explain please?
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.
Warning Toxic!
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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.
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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.
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.
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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.
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.
Warning Toxic!
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The only criticism is that you have posted misleading information!
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.
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.
Nope, gotta have them ground engineers doing it while aircraft is parked on the ground.
Classsic and NG that be.
