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Main Forums => The Roundtable => Topic started by: Hawkmoon on March 10, 2011, 11:08:10 AM

Title: I'm confused -- and I can't breathe
Post by: Hawkmoon on March 10, 2011, 11:08:10 AM
http://www.click2houston.com/news/27137202/detail.html

So the FAA has secretly required that emergency oxygen serving toilet compartments on commercial aircraft be removed ... in order to keep the flying public safer?

Can any of my fellow APSers explain to me exactly how being exposed to possible suffocation in the event of an emergency makes me safer?
Title: Re: I'm confused -- and I can't breathe
Post by: Jamisjockey on March 10, 2011, 12:03:21 PM
I used to work for the FAA. Don't try and apply logic to their decision making....you'll save yourself all manner of stressful confusion.
Title: Re: I'm confused -- and I can't breathe
Post by: griz on March 10, 2011, 12:22:44 PM
Reading between the lines it sounds as if somebody figured out a potential way the oxygen generators could be used by a bad guy.
Title: Re: I'm confused -- and I can't breathe
Post by: Fly320s on March 10, 2011, 12:25:09 PM
Don't think FAA.  Think Homeland Security.  Now you know as much as I do about it.
Title: Re: I'm confused -- and I can't breathe
Post by: Harold Tuttle on March 10, 2011, 12:26:31 PM
i wonder if given access to the closed room with the hardware
someone mcguyvered the 02 generator into a flamethrower?

maybe you could inline a vodka bottle and a coffee stirrer and make a thermic lance

Title: Re: I'm confused -- and I can't breathe
Post by: 280plus on March 10, 2011, 12:39:14 PM
Do they serve 151 on board? 151 and some O2 would probably do a pretty good job.

Anybody remember being able to smoke on an airplane? In the 70's we even smoked the funny stuff in the restrooms for crying out loud. While everybody else on the plane was at 30,000 feet me and my friends were just a little bit higher.  >:D

 :angel:

Title: Re: I'm confused -- and I can't breathe
Post by: griz on March 10, 2011, 01:06:39 PM
Looked up O2 generators and discovered they are basically a mixture of sodium chlorate and lesser amounts of some other stuff.  After it is ignited it burns (my simple term, wiki calls it a chemical reaction) releasing lots more oxygen than needed for combustion.  So I would guess some enterprising terrorist could find a way to add a little more fuel to that fire and make a big boom.  After all it was malfunctioning O2 generators that brought down that Valujet about 15-20 years ago.
Title: Re: I'm confused -- and I can't breathe
Post by: 280plus on March 10, 2011, 01:16:45 PM
Well, if you notice Achmed two seats over buying lots of 151 nippers but not drinking any get suspicious and don't let him make it to the rest room!  :O
Title: Re: I'm confused -- and I can't breathe
Post by: CSM Kersh on March 10, 2011, 01:43:44 PM

Speaking of Achmed... (http://www.youtube.com/watch?v=1uwOL4rB-go)

Title: Re: I'm confused -- and I can't breathe
Post by: roo_ster on March 10, 2011, 04:22:11 PM
FAA also wanted to regulate model aircraft like commercial UAVs.  Senate is working to stymie that.
Title: Re: I'm confused -- and I can't breathe
Post by: Hawkmoon on March 10, 2011, 06:20:31 PM
Reading between the lines it sounds as if somebody figured out a potential way the oxygen generators could be used by a bad guy.

That's about what I got out of it, too. Okay, remove the DIY bomb kits from the lavatories, I'm down wit dat. But how's about at least substituting a small oxygen bottle, or some sort of rescue breather mask that recycles your own breathing by scrubbing the CO2? At least give people enough air to make it back to their seat (and oxygen mask).
Title: Re: I'm confused -- and I can't breathe
Post by: KD5NRH on March 10, 2011, 10:28:04 PM
That's about what I got out of it, too. Okay, remove the DIY bomb kits from the lavatories, I'm down wit dat. But how's about at least substituting a small oxygen bottle, or some sort of rescue breather mask that recycles your own breathing by scrubbing the CO2?

Or make the hose a bit longer and put the generator somewhere completely inaccessible from the bathroom.
Title: Re: I'm confused -- and I can't breathe
Post by: Jocassee on March 10, 2011, 10:43:37 PM
Speaking of Achmed... (http://www.youtube.com/watch?v=1uwOL4rB-go)



"Good evening...infidels."
Title: Re: I'm confused -- and I can't breathe
Post by: 280plus on March 11, 2011, 06:54:18 AM
"I KILLYOU!"  :mad:
Title: Re: I'm confused -- and I can't breathe
Post by: Jamisjockey on March 11, 2011, 08:19:10 AM
That's about what I got out of it, too. Okay, remove the DIY bomb kits from the lavatories, I'm down wit dat. But how's about at least substituting a small oxygen bottle, or some sort of rescue breather mask that recycles your own breathing by scrubbing the CO2? At least give people enough air to make it back to their seat (and oxygen mask).

You can make it from the head back to your seat IMHO without O2 in the bathroom.
Title: Re: I'm confused -- and I can't breathe
Post by: Hawkmoon on March 11, 2011, 02:03:07 PM
You can make it from the head back to your seat IMHO without O2 in the bathroom.

That depends on too many factors outside of your control:

Title: Re: I'm confused -- and I can't breathe
Post by: Fly320s on March 11, 2011, 02:22:36 PM
You can make it from the head back to your seat IMHO without O2 in the bathroom.
Time of useful consciousness at 35,000 feet is about 20 seconds.
Title: Re: I'm confused -- and I can't breathe
Post by: KD5NRH on March 11, 2011, 02:34:59 PM
Time of useful consciousness at 35,000 feet is about 20 seconds.

Including time to figure out WTF is happening, realize it's not stopping, pull up your pants, etc.

Throw in trying to swing from the can onto a wheelchair, and they're basically saying the handicapped should die.
Title: Re: I'm confused -- and I can't breathe
Post by: Fly320s on March 11, 2011, 02:54:36 PM
No one will die. An emergency decent will get the plane down to a breathable altitude in 2 to 3 mintues.
Title: Re: I'm confused -- and I can't breathe
Post by: Hawkmoon on March 11, 2011, 05:35:10 PM
No one will die. An emergency decent will get the plane down to a breathable altitude in 2 to 3 mintues.

Okay. According to you, "Time of useful consciousness at 35,000 feet is about 20 seconds." You can fly the plane down to where there's oxygen in 2 to 3 minutes -- which is between 6 and 9 times longer that the period of "useful consciousness" (whatever that is). And how long does it take for oxygen deprivation to result in permanent dain bramage
Title: Re: I'm confused -- and I can't breathe
Post by: Tallpine on March 11, 2011, 08:00:15 PM
Okay. According to you, "Time of useful consciousness at 35,000 feet is about 20 seconds." You can fly the plane down to where there's oxygen in 2 to 3 minutes -- which is between 6 and 9 times longer that the period of "useful consciousness" (whatever that is). And how long does it take for oxygen deprivation to result in permanent dain bramage

I've always heard about five minutes.
Title: Re: I'm confused -- and I can't breathe
Post by: Stickjockey on March 11, 2011, 08:34:14 PM
Hawkmoon, flight crews are by regulation supposed to have oxygen supplies for any flight above (Fly320s- is it 12,500 feet? It's been a while.)
Title: Re: I'm confused -- and I can't breathe
Post by: Hawkmoon on March 11, 2011, 08:45:25 PM
Hawkmoon, flight crews are by regulation supposed to have oxygen supplies for any flight above (Fly320s- is it 12,500 feet? It's been a while.)

Flight crew is not the issue. The issue is the poor passenger sitting in the aft lavatory, just starting a #2 event, when the cabin depressurizes. According to Fly320s, the poor guy (if it's a guy) has 20 seconds to finish his dump, clean himself, pull up his drawers and trousers, exit the lavatory, and make it to a vacant seat that has an oxygen mask. If it takes Fly320s 2 minutes to make it down to an altitude that has sufficient oxygen, that leaves the passenger 1 minute and 40 seconds behind the curve.
Title: Re: I'm confused -- and I can't breathe
Post by: Fly320s on March 11, 2011, 09:35:14 PM
Okay. According to you, "Time of useful consciousness at 35,000 feet is about 20 seconds." You can fly the plane down to where there's oxygen in 2 to 3 minutes -- which is between 6 and 9 times longer that the period of "useful consciousness" (whatever that is). And how long does it take for oxygen deprivation to result in permanent dain bramage
I'm no medical expert, but I don't think 10 minutes exposure to the pressure at 35,000 feet is enough time to deprive someone of oxygen to the extent that brain damage will occur. My best guess is that a person will pass out, which will cause a lower respiration and heart rate. I believe that this lower rate will allow a person to survive "a long time" without supplemental O2. I base this guess on the fact that many people have climbed Everest without using supplemental O2. Granted, they are in excellent physical condition at the start, and they have many days to acclimate to the higher altitude, but they are still strongly exerting themselves at high altitude. So, based on the irrefutable scientific proof ( =D), I think most everyone can survive for 10 minutes at 39,000 feet.

In any case, the plane should be rapidly descending. Even at a cabin altitude of 25,000, there should be enough pressure to get the oxygen into your blood.

Hawkmoon, flight crews are by regulation supposed to have oxygen supplies for any flight above (Fly320s- is it 12,500 feet? It's been a while.)
Yes, basically, but it applies to the cabin pressure altitude. I am not required to use O2 during normal operations except under certain conditions. The cabin pressure in the A320 never exceeds 8,000.

Title: Re: I'm confused -- and I can't breathe
Post by: Fly320s on March 11, 2011, 09:49:19 PM
From an FAA training paper on high-altitude and pressurized airplanes.

http://www.faa.gov/pilots/training/airman_education/media/ac%2061-107a.pdf

Effective Performance Time (EPT) or Time of Useful Consciousness (TUC) is the amount of time in which a person is able to effectively or adequately perform flight duties with an insufficient supply of oxygen. EPT decreases with altitude, until eventually coinciding with the time it takes for blood to circulate from the lungs to the head usually at an altitude above 35,000 feet.

Title: Re: I'm confused -- and I can't breathe
Post by: Fly320s on March 11, 2011, 10:08:20 PM
I did a quick search for info about living at high altitude. One article I read said that roughly 22,000 feet is the limit for humans to live long term without supplemental oxygen. The article cited a study where a number of people lived at 22,000 feet without supplemental O2 for a period of two years.

So, I guesstimate that an average person can live for 10 minutes at 35,000+ feet.  I couldn't find any info on how long a person can be expected to live at that high an altitude.
Title: Re: I'm confused -- and I can't breathe
Post by: sanglant on March 11, 2011, 10:22:57 PM
we're just going to have to do some testing. anyone have access to an pressure tank? while we're there i've been wanting to try something anyway. i'll go first. >:D
Title: Re: I'm confused -- and I can't breathe
Post by: KD5NRH on March 12, 2011, 01:21:04 AM
I'm no medical expert, but I don't think 10 minutes exposure to the pressure at 35,000 feet is enough time to deprive someone of oxygen to the extent that brain damage will occur. My best guess is that a person will pass out, which will cause a lower respiration and heart rate. I believe that this lower rate will allow a person to survive "a long time" without supplemental O2.

So what's the effect of sudden, unexpected decompression on someone with a serious heart condition?  What about asthma?
Title: Re: I'm confused -- and I can't breathe
Post by: Fly320s on March 12, 2011, 09:24:04 AM
So what's the effect of sudden, unexpected decompression on someone with a serious heart condition?  What about asthma?
Explosive decompression is beneficial!  It helps get things unstuck.

I don't know; I'm not a human mechanic.
Title: Re: I'm confused -- and I can't breathe
Post by: 230RN on March 12, 2011, 02:26:43 PM
Quote
Explosive decompression is beneficial!  It helps get things unstuck.


Yeah, like all the nitrogen gets unstuck from solution in the blood.

I'm not clear on what the "vulnerabiltiy" was.  
Title: Re: I'm confused -- and I can't breathe
Post by: Fly320s on March 12, 2011, 03:59:47 PM
Access is through the door that pops open to allow the mask to drop. The oxygen starts when the mask is pulled taught.

The canisters get pretty hot, so maybe that is useful to terrorists.

Thankfully, DHS and FAA is keeping that info from the airlines. Obviously, we can't be trusted with that info.  :facepalm:
Title: Re: I'm confused -- and I can't breathe
Post by: Hawkmoon on March 12, 2011, 05:49:34 PM
Thankfully, DHS and FAA is keeping that info from the airlines. Obviously, we can't be trusted with that info.  :facepalm:

Yeah. God forbid the PILOT should know how the plane works.
Title: Re: I'm confused -- and I can't breathe
Post by: Fly320s on March 12, 2011, 11:25:14 PM
Yeah. God forbid the PILOT should know how the plane works.
I meant that the FAA won't tell us why they issued an emergency Airworthiness Directive to all airlines telling them to remove the oxygen equipment from the lavs. I do know how the plane works... mostly.  :O  Actually, I just finished my three-day recurrent training. Legal for another year!
Title: Re: I'm confused -- and I can't breathe
Post by: RocketMan on March 13, 2011, 01:29:56 AM
I meant that the FAA won't tell us why they issued an emergency Airworthiness Directive to all airlines telling them to remove the oxygen equipment from the lavs. I do know how the plane works... mostly.  :O  Actually, I just finished my three-day recurrent training. Legal for another year!

So, they trust you enough to fiddle with the thing that makes the plane go up and down, but don't trust you enough to tell you why the O2 generator was removed from the potty room.  What the heck is that about?
Title: Re: I'm confused -- and I can't breathe
Post by: dogmush on March 13, 2011, 09:14:58 AM
Need to know?
Title: Re: I'm confused -- and I can't breathe
Post by: 230RN on March 14, 2011, 03:17:21 PM
^ Oh.  I guess I'm supposed to stay "unclear on what the 'vulnerabiltiy' was."

Ooookaaay.

Terry, 230RN
Title: Re: I'm confused -- and I can't breathe
Post by: dogmush on March 14, 2011, 04:26:47 PM
I didn't say it was a good reason, but it makes sense from a OPSEC standpoint.  If I was in charge of the DHS, and I wouldn't necessarily tell the pilot every little way to make an IED and bring down a plane.  It adds nothing to security and adds another person to leak tactics.

Title: Re: I'm confused -- and I can't breathe
Post by: Tallpine on March 14, 2011, 06:48:33 PM
I didn't say it was a good reason, but it makes sense from a OPSEC standpoint.  If I was in charge of the DHS, and I wouldn't necessarily tell the pilot every little way to make an IED and bring down a plane.  It adds nothing to security and adds another person to leak tactics.



An airplane restroom is definitely a good place for leaks  ;)
Title: Re: I'm confused -- and I can't breathe
Post by: 230RN on March 14, 2011, 07:12:38 PM
Quote
It adds nothing to security and adds another person to leak tactics.

Mmmmm.... agreed.  Not being a security person, I hadn't thought of that.

I learn somethin' every day, don't I?
 
TNX.

Terry, 230RN