JohnBurke

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?

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

decrabbitz

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. I’ve 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. I’m just trying to present a real world time frame.

But it doesn’t matter how fast you can dive to sea level—that 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 “Main Cargo Fire”warning. Sitting in the cockpit, you don’t know if it’s 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 don’t 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, I’m no expert. When you take the history of inflight fires and the fact that you don’t know what is going on in the back of the airplane, I’d sure hate to be at FL250 when the clock expires....

JohnBurke

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."

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?

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.

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

Thank you, John Burke, for this reply!!!

ptarmigan

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

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

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

ptarmigan

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

rickair7777

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

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.