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ptarmigan
03-29-2018, 05:32 AM
Reposting an older article (https://airlinesafety.blog/2012/02/02/inflight-fire/) that is still timely.


JohnBurke
03-29-2018, 08:53 AM
Good article, and it doesn't matter that it wasn't written yesterday.

My usual response to talks about onboard fires is that there's nothing better than the smell of smoke in the cockpit, but that has to be qualified by noting that I've spent a good deal of my career fighting fires from the air, so smoke in the cockpit is also the smell of money.

I've had several on board fires over the years; Janitrol heaters twice, a burning hydraulic pump once, and engine oil from a failed engine component on a large radial. The heaters were put out manually, using a nomex jacket to smother the fire as well as stopping the fuel. The oil went out as the supply stopped with shutdown. The hydraulic pump, however, did not.

In the case of the hydraulic pump, it was a single engine turbine aircraft, and in the time it took to make an overhead at the runway, over the numbers, until touchdown, the cockpit went from a trace scent of burning insulation to a cockpit full of smoke. On the rollout, by midfield I couldn't read the instruments. Point is, it went fast, as fires do. The rule of thumb is that a fire doubles in size every 60 seconds, though the acceleration isn't linear. There are no guarantees that adequate time exists, and there's a good chance that it's not long. Getting to the ground and getting out is critical.

Just as the article notes that descent increases fire behavior, once on the ground venting the aircraft does, too. Every door that's opened will increase fire behavior, and also change the direction that the fire moves. Anyone that's ever blown on a campfire understands why.

I've been doing fire in one capacity or another much of my adult life and the one solitary piece of advice I can give, when it comes to fire, is that there is no such thing as a false alarm. Every firearm is loaded, and every fire alert should be taken seriously. Very, very seriously.

ptarmigan
03-29-2018, 01:21 PM
Great response, fully agree, thank you!


JohnBurke
03-29-2018, 01:31 PM
Are you the author of that article, by chance?

It's well written, and takes a different tack than most commentary about inflight fires. I thought it was well placed and very well presented.

ptarmigan
03-29-2018, 05:16 PM
Are you the author of that article, by chance?

It's well written, and takes a different tack than most commentary about inflight fires. I thought it was well placed and very well presented.

Yes. Thank you!

Cheddar
04-05-2018, 01:12 AM
That was fantastic, and terrifying. I long ago read an article about a Ď17 minuteí rule - 17 minutes being a golden number between first indication and losing the aircraft. I thought I had downloaded it but canít find it.

About 10 years ago when working for a long haul VIP charter, we had the opportunity to train with the flight attendants on a simulated in flight fire over the water (it was a one jet, small company). Could we find all the emergency equipment, could we coordinate, etc. I think itís safe to say we were all deeply humbled and unimpressed with our knowledge and perceptions on just how Ďgoodí we were.

Thanks for sharing!!!


Sent from my iPhone using Tapatalk

decrabbitz
04-10-2018, 08:59 PM
Ptarmigan;

Thanks for posting an interesting article, it's a topic I think about on every ocean crossing (777 cargo). I think there is some disconnect on the history of inflight fires and the current procedures to cope with them. I'll try and be brief, await others thoughts, and hopefully have a decent discussion on the topic.

The history I refer to is the "20 minutes", an amount of time commonly agreed upon as the flight time remaining with an onboard fire.

The current procedures (cargo) I refer to are a descent to FL250, depressurizing, and cruising until 60 miles from landing (this could be over an hour).

Here is my take on the disconnect. If I get a main cargo deck fire warning (and I have to assume it's real) I start a mental (if not physical) 20 minute timer. Where do I want to be when that time runs out? At FL250, 45 mins from land? Hoping the engineers are right about starving the fire? Is it a lithium battery fire (10,000lbs on my last crossing) and it will never starve?

Would it not be a better use of time (the rest of your life) to descend immediately to a safe ditching altitude (say 1000'agl) and analyze the situation? From FL 330 it would take 20 minutes to get down and prepare to ditch on a good day, any delay with investigation and fire checklists at altitude will take you out of your 20 minute survivability window.

At 1000'agl, assess the situation. Is it a real fire? If so, you are ready to ditch. If not, you have the fuel to climb back up and divert (which you were going to do anyways).

I'm not an expert on this topic and am open to hearing others thoughts......

rickair7777
04-11-2018, 03:53 AM
Tradeoffs. The fire will burn much better at 1000' than at FL250.

But like you say, if it's a big load of Li, then the O2 partial pressure isn't going to matter much either way. If it were me, and there was no Li onboard, I'd stay at 250... you can breath with the mask but a normal fire really can't.

decrabbitz
04-11-2018, 05:41 AM
Tradeoffs. The fire will burn much better at 1000' than at FL250.

But like you say, if it's a big load of Li, then the O2 partial pressure isn't going to matter much either way. If it were me, and there was no Li onboard, I'd stay at 250... you can breath with the mask but a normal fire really can't.


True, the fire will probably will burn better at 1000agl, but I believe its going to burn regardless. If there are findings out there that cargo fires extinguished on their own by oxygen starvation, I'd feel a bit better, I just haven't heard of this happening.

With no Li onboard, wouldn't you be better staying at cruise altitude (FL330?), or climbing as high as possible, to starve the fire? If FL250 is good, then FL370 is great. Obviously we are talking no pax here, and you are going to have to see a doc for the physiological impact, but if you are putting ALL your faith in oxygen-starving a fire, you might as well go all in and climb.

As an aside, how do you know you don't have any Li onboard? Crew bus driver says there's a lot of "undeclared" DG.

rickair7777
04-11-2018, 06:23 AM
True, the fire will probably will burn better at 1000agl, but I believe its going to burn regardless. If there are findings out there that cargo fires extinguished on their own by oxygen starvation, I'd feel a bit better, I just haven't heard of this happening.

With no Li onboard, wouldn't you be better staying at cruise altitude (FL330?), or climbing as high as possible, to starve the fire? If FL250 is good, then FL370 is great. Obviously we are talking no pax here, and you are going to have to see a doc for the physiological impact, but if you are putting ALL your faith in oxygen-starving a fire, you might as well go all in and climb.

As an aside, how do you know you don't have any Li onboard? Crew bus driver says there's a lot of "undeclared" DG.

FL250 is about the highest cabin pressure where you can stay fully functional using a standard O2 mask. Much higher and you might get bent and would have too low of a partial pressure to not be impaired.

Any normal fire is probably going to go out at that altitude. Only something with its own oxidizer, or that burns hot enough to oxidizer other materials, will keep going.

From a chemistry perspective, 250 should do the trick.

JohnBurke
04-11-2018, 06:47 AM
The current procedures (cargo) I refer to are a descent to FL250, depressurizing, and cruising until 60 miles from landing (this could be over an hour).

Here is my take on the disconnect. If I get a main cargo deck fire warning (and I have to assume it's real) I start a mental (if not physical) 20 minute timer. Where do I want to be when that time runs out? At FL250, 45 mins from land? Hoping the engineers are right about starving the fire? Is it a lithium battery fire (10,000lbs on my last crossing) and it will never starve?

Would it not be a better use of time (the rest of your life) to descend immediately to a safe ditching altitude (say 1000'agl) and analyze the situation? From FL 330 it would take 20 minutes to get down and prepare to ditch on a good day, any delay with investigation and fire checklists at altitude will take you out of your 20 minute survivability window.

At 1000'agl, assess the situation. Is it a real fire? If so, you are ready to ditch. If not, you have the fuel to climb back up and divert (which you were going to do anyways).


FL330 to sea level in 20 minutes? That's a descent rate of 1,650 fpm. If you're intending to reach the surface and ditch because you're on fire, you're going to do a leisurely descent to the surface at less than 2,000 fpm? You should easily be able to get 5,000 fpm or better with the boards out, and that puts you on the ground in six minutes. You're going to get to 1,000 and then begin doing checklists? Get them done on the way down. If everything can't be accomplished in five minutes, then brush up on those procedures. 5 minutes is more than enough time. You're on fire.

Five minutes is an eternity.

Why not spend the other 14 minutes enroute to your divert field, at altitude, on oxygen, running the relevant fire procedures for your aircraft? True airspeed's higher, oxygen lower in partial pressure, fire behavior less aggressive. You might have an artificially-derived 20 minutes on your personal clock, but go ditching in the North Atlantic, and you have one or two minutes in the water before you succumb, if you survive the impact at all.

If you have a self-oxidizing fire, then you won't be starving it of oxygen by remaining at altitude. In that case, work on reducing those five minutes to less. There are no guarantees that you've got 20 minutes.

Of curiosity, your position shows MD-11 first officer, but you stated you're doing 777 cargo. Different procedures, and the MD-11 relies on discharging a bottle and sealing the compartment, with a 90 minute timer to the next bottle. Not so for the 777, correct?

Yes. Thank you!

Thank you. I ordered Angle of Attack, linked off the website at the opening of this thread. Looking forward to the read.

decrabbitz
04-11-2018, 08:01 PM
Yes, I am a 777FO, need to update profile.

Correct, 777 is different (if I remember the -11 right). If you get a main cargo deck fire, there is no fire suppression system (bottle). There is the overhead system that will attempt to put out a fire in a can by penetrating it and injecting suppressant. But it will not address pallet loaded cargo or a non-can related fire. The only means of fighting those kind of fires is oxygen starvation (the procedure) or taking a hand held into the back (prohibited).

I agree, you can dive the aircraft to sea level in 5-6 minutes. Iíve added more time in for the reaction, decision, and get ready to put the airplane in the water time. In a controlled environment where you knew the warning was coming, you could obviously shave a few minutes off. Iím just trying to present a real world time frame.

But it doesnít matter how fast you can dive to sea levelóthat is not the procedure! The procedure is to depressurize and get to FL250, which you might as well do slowly.

So, back to my disconnect between procedure and time available. In my scenario, the 777 is more than an hour from land when it presents a ďMain Cargo FireĒwarning. Sitting in the cockpit, you donít know if itís a false warning, a Li battery fed fire, a small smoldering fire or one that is soon to be out of control. The book says do not go back and look. Two of those scenarios could be survivable by using the procedure. Two of those scenarios have you possibly going uncontrollable before you can get to sea level if you follow the procedure. The problem is, you donít know what you have, and the clock is ticking....

If you were to descend to sea level immediately (while preparing to ditch) and then investigate (wait for smoke, look for failing systems, hell-blow off the book and send someone into the back to investigate) you could determine which of the 4 scenarios you have. If there is no fire, you can climb back up and divert. If there is a Li battery fire or one that is out of control, you are in an infinitely better position than you would be at FL250.

I present this scenario for discussion, like I said, Iím no expert. When you take the history of inflight fires and the fact that you donít know what is going on in the back of the airplane, Iíd sure hate to be at FL250 when the clock expires....

JohnBurke
04-11-2018, 09:41 PM
But it doesnít matter how fast you can dive to sea levelóthat is not the procedure! The procedure is to depressurize and get to FL250, which you might as well do slowly.


No, you might as well do quickly. It's about you retaining consciousness every bit as much as about the fire. The fire is irrelevant if you lose consciousness, and your ability to remain conscious is irrelevant if you don't get pointed toward a diversion location.

Have you ever intentionally shut off all the bleeds or packs at altitude, above FL350 before in a widebody aircraft? It can take a long time to depressurize, even running the outflow valve open. If it remains closed, it can take a longer time.

If you descend to a low altitude and have some distance to go, bearing in mind that in some diversion scenarios you may arrive with previous little time remaining in fuel or survivability, you're going to burn what fuel you've got, reduce your true airspeed, and increase your time to your divert point. There is no value descending to the water immediately if you're going to spend time trouble shooting, analyzing, running checklists, and taking selfies. Either stay at altitude where it can benefit you, or get to the water and ditch. No point going down there "just in case."


Sitting in the cockpit, you donít know if itís a false warning, a Li battery fed fire, a small smoldering fire or one that is soon to be out of control. The book says do not go back and look. Two of those scenarios could be survivable by using the procedure. Two of those scenarios have you possibly going uncontrollable before you can get to sea level if you follow the procedure. The problem is, you donít know what you have, and the clock is ticking....


Procedure exists for a reason. If it's a "false warning" then it needs to be treated the same as a fire. Dont' guess as to what you've got. Follow the procedure. You have a choice to make; you're going to attempt to extinguish or slow the fire. High or low, you're not going to extinguish a self-oxidizing fire, other than you may be able to cool it or reduce it depending on what's fueling or reacting with the fire. Remember that fire has four points; the fire tetrahedron (often incorrectly taught as the "fire triangle"). Fuel, heat, oxygen, and a chemical reaction. Interrupt or change any of those four, you control the fire, or change its behavior.

The only thing you can do by descending, so far as the fire is concerned, is increase fire behavior; make it more aggressive. Remember that the ignition source may not be what's burning or causing the fire to burn. You may have had a lithium battery start it, but it may be burning in conventional materials; the more it grows the harder it will be to control and the more "exposures" (other matererial and fuels) it will ignite. Second by second, minute by minute. You may or may not be able to terminate the ignition source (which could be en electrical short, hot bleed, or any other number of sources), but you may be able to limit fire spread or reduce fire behavior by depressurizing, remaining in a lower-pressure environment, altering airflow or ventilation, discharging available extinguishing agents, etc.

Your progress toward a diversion field will be much faster at altitude, all things equal, minus a given wind, so long as your true airspeed remains higher, and if fuel is an issue diverting, you're going to burn a lot less of it at FL250 than 050. Correct?


If you were to descend to sea level immediately (while preparing to ditch) and then investigate (wait for smoke, look for failing systems, hell-blow off the book and send someone into the back to investigate) you could determine which of the 4 scenarios you have. If there is no fire, you can climb back up and divert. If there is a Li battery fire or one that is out of control, you are in an infinitely better position than you would be at FL250.


You're going to wait for smoke? You're going to wait until you've sorted all this out before diverting?

At the first indication of fire you need to be diverting. UPS 6 might have been able to make straight for Doha, instead of attempting a return to Dubai. Might have made it. If you've studied the incident, it's horriffic in every respect, but you must know that by descending, you're going to increase fire behavior. You must also know that if you intend to ditch, you're not going to be flying around leisurely at 1,000' looking for a good line to make your run into the water, and certainly not to be running checklists. If you're going to ditch, you're going to be going straight down and getting it in the water quickly, with all checklists completed, everyone briefed on the way down. You might wish to minimize fire spread and behavior until you're committed to that point.

You're certainly not going to descend to 1,000 above the waves, where your fire behavior and growth will be the most aggressive, think about it, trouble shoot it, prepare to ditch, then climb back up to altitude and decide to divert. The decision to divert needed to be on the heels of the fire warning. I don't know if you've ever been on fire in flight. I have, several times, and you have an emergency on your hands, whether it's a light, a failed sensor or detector, or a birthday candle. If you're over the ocean and you've got distance to go to get to a diversion point, you don't have the fuel to be descending to the water, screwing with your four scenarios, picking one, then deciding it was all a misunderstanding before climbing back to altitude...or attempting to divert. Too little, too late. It's a one-shot deal; divert, sort it out on the way, and if you need to ditch, make your rapid emergency descent and do it.

That said, no one can account for every possible scenario or situation, and in your finest hour when there is no one to make the call for you, as a crew you have a decision to make. Fortunately or not, you have the rest of your life to do it.


I present this scenario for discussion, like I said, Iím no expert. When you take the history of inflight fires and the fact that you donít know what is going on in the back of the airplane, Iíd sure hate to be at FL250 when the clock expires....

If you go zipping down to the water to troubleshoot, run checklists, and screw around, you may be the one that just made the clock expire by promoting fire behavior in an unfavorable manner. You may have just cancelled your own check.

Freelance procedures at your peril. Guess and risk guessing wrong. That's a big gamble. Does everyone else on board agree?

huseyydemm
04-12-2018, 04:37 AM
Thank you, John Burke, for this reply!!!

ptarmigan
04-12-2018, 05:29 AM
Wow, this has been an excellent discussion. I enjoy reading it as it also highlights areas that I might edit the article to make it clearer or answer questions in advance. If anyone has such suggestions, I am always interested, for this, or any of the other articles. I strive for accuracy.

I did add a couple of points to it regarding flight controls, particularly the issue of how FBW system envelope protection features might come into play, as well as the consideration of their architecture for alternate control strategies. The UPS 6 crew lost most of their elevator control due to the fire, but the autopilot is FBW, for example...

Anyway, take a look at the article again for these additions and, again, I welcome suggestions and additions if you have any thoughts on that. You can post them here to continue this discussion (these types of discussions can save lives), or to the contact info on the blog. - Thanks!

Airbum
04-12-2018, 02:21 PM
UPS Flight 6 had around 3:51 minutes from the very first alert of a fire to the Captain stating he had no aircraft pitch control. At 7:08 minutes he had no more O2 and left his seat to find O2. He never returned.

Asiana Airlines Cargo Flight 991 was lost to radar contact 8 minutes after they reported a fire on board. (not a verified Li battery fire but over 800 lbs of them where delcared)

If its a li battery fire you will not have much time.

ptarmigan
04-12-2018, 03:46 PM
Thank you. I ordered Angle of Attack, linked off the website at the opening of this thread. Looking forward to the read.

Thank you! It seems to be getting a lot of attention in the industry, hopefully influencing training and our approach to problems.

ptarmigan
04-12-2018, 03:48 PM
UPS Flight 6 had around 3:51 minutes from the very first alert of a fire to the Captain stating he had no aircraft pitch control. At 7:08 minutes he had no more O2 and left his seat to find O2. He never returned.

Asiana Airlines Cargo Flight 991 was lost to radar contact 8 minutes after they reported a fire on board. (not a verified Li battery fire but over 800 lbs of them where delcared)

If its a li battery fire you will not have much time.

Yes, this is serious stuff. Malaysia 370 was carrying a bunch of them also...

rickair7777
04-13-2018, 06:11 AM
Yes, this is serious stuff. Malaysia 370 was carrying a bunch of them also...

Based on a lot of info that came light afterwards, it looks like the CA crashed the plane.

But you could make a very logical case that they became incapacitated while fighting a fire, and that some avionics were disabled fighting an electrical fire.

JohnBurke
04-13-2018, 06:49 AM
There was actually nothing other than popular media reports and Malaysian propaganda to suggest that the captain crashed the airplane. Most of what was given was speculation, and fairly wild stuff at that.

Oceans are very big places with no radar coverage and spotty communication. Lots of places to disappear.

On Lithium batteries; I got onboard for a trip to Afghanistan some years ago, and saw pallets stacked inside containers from one end of the main deck to the other. I walked the cargo and noted big stickers on the pallets, which were stacked two high, saying "DO NOT STACK." Upon closer inspection, I found that the entire load was lithium batteries.

I called home plate and was told "it's just a three hour flight, and they really need the batteries." I refused the flight, made them offload everything and remove half the pallets. I was told that if it would make me feel better, they could just remove the stickers, and that future flights would simply have the stickers removed. Not on my flights.

On another trip, originating in Amsterdam (for me) headed westbound, I found the hazmat buried halfway down the main deck on the far side of the airplane, instead of up front. It included half a pallet of lithium batteries, with a 30 gallon drum of an accelerant on top, on it's side on a 45 degree angle, so all the pressure of the weighted edge bore directly on the batteries. It was surrounded by packed-in accelerants of various types, all mixed on one pallet. I refused the flight; pull it off, correct it, and put it up front where we have access. They did, unhappily.

I was born yesterday, but it was pretty early in the day.

rickair7777
04-13-2018, 07:58 AM
Yes there's obvious potential motive for other parties to slander the CA, not ruling that out by any means. I was a proponent of the fire theory from the outset. But to explain everything with a fire, a lot of stars have to line up.

ptarmigan
04-13-2018, 08:25 AM
Yes there's obvious potential motive for other parties to slander the CA, not ruling that out by any means. I was a proponent of the fire theory from the outset. But to explain everything with a fire, a lot of stars have to line up.

I agree with John completely, and I have to say his posts have been really excellent. Read every word of them and take heed!

As for Malaysia, look at the timing from departure. Matches several other Li events...

decrabbitz
04-17-2018, 10:56 PM
Good discussions. I put some of the responses into a train of thought (777 cargo specific):

If you get a Main Cargo Fire warning, you have to take the most conservative action and assume it to be real (even if statistics prove it more likely to be false)

You have no way of knowing whether it is a Li battery fire or not. According to OPs article, "While the fact that a fire might be caused by Lithium batteries does not change most of the recommendations, it can force a situation where the ONLY option is an immediate landing or ditching."

Given two options, fly at FL250 for what could be more than an hour, or descend and prepare to ditch, the conservative pilot would have to assume the worst and prepare to ditch.

Thoughts?

JohnBurke
04-23-2018, 07:13 PM
You sound like you're springloaded to ditch. You've already indicated that you want to fly down to 1,000 and stay there, ready to ditch, but that if you find it was a false alarm, then you'll climb back to altitude and continue on your way. You've got fuel for that?

There is zero advantage to loitering at 1,000. Fuel burn is higher. Fire activity is more aggressive. True airspeed is slower. You're making slower progress toward a boat, island, ETP alternate, or whatever.

If you're made the decision to ditch, you've made it at altitude, and you're not going to dive to 1,000', run checklists, evaluate, think about it, see if it's a false alarm, then ditch. If you truly need to ditch, you're going to be ditching from FL350; you're going straight there and ditching. Or you're going to 250 and making a beeline for your ETP alternate, then ditching from 250 if it becomes necessary.

If you go to 1,000, it's not a matter of sorting it out, seeing if it's a false alarm, then pressing on when you decide it wasn't so bad after all. If it wasn't so bad after all, you should never have gone there, period. If it is so bad, you're going straight there from altitude, and it will go fast.

I'm not sure why you keep posting the same question again and again, and saying let's discuss it (again). I'm having a hard time understand why you'd try to do these things.

742Dash
04-25-2018, 09:11 AM
Given two options, fly at FL250 for what could be more than an hour, or descend and prepare to ditch, the conservative pilot would have to assume the worst and prepare to ditch.

Thoughts?

I think that you are vastly overestimating your chances of surviving a ditching in the open ocean.

2StgTurbine
04-29-2018, 01:58 PM
I think that you are vastly overestimating your chances of surviving a ditching in the open ocean.

This. Your chances of surviving a ditching in the open ocean are about as good as surviving a large lithium-ion battery fire. You might as well follow a published checklist rather than improvise because you have a hunch that hanging out at FL250 for a while will negatively impact a possible ditching.



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