Pilot incapacitated and plane circles Gulf of Mexico for several hours

[MrRiplEy[H]]

During decompression, before anything else (assuming you know it is happening i.e. rapid decompression) You need to get your oxygen mask on. From what I am told by my commercial pilot buddies, you only have a matter of seconds to get the mask on before falling unconscious. If you don't, everyone dies.

This is what I never understood. If you can hold your breath for approx 2 minutes how can hypoxia take you out in seconds? I guess that while you hold your breath the air supply in the lungs keeps you going but if there's no air in lungs you pass out fast.

[Tupac]

Not neccesarily seconds - like Golfer said, an individuals reaction to hypoxia varies. Some people won't recognize it until its too late. For me my first symptom is tiredness, but usually when I'm up high enough to worry about hypoxia I will have the pulse oxymeter going and be ready to put on oxygen if need be.

[Golfer]

This is what I never understood. If you can hold your breath for approx 2 minutes how can hypoxia take you out in seconds? I guess that while you hold your breath the air supply in the lungs keeps you going but if there's no air in lungs you pass out fast.

It's not like being immersed in water where you can just hold your breath. At altitude your time of useful consciousness can be anywhere from 1-7 seconds depending on your health in a bona rapid/explosive decompression. Its more like instantly being taken from a depth of 100' to the surface. You'll have some of the worst pain you ever felt, your sinuses would empty if you were stuffed up and your body would act like a shaken up beer can. You'd actually bloat and your lap belt would be extremely tight and I think I mentioned you'd be in for some of the worst pain you'd ever felt in your life?


While that sounds great to a masochist what's actually more dangerous is the subtle onset of a slow decompression and failure of an alerting system for some reason. If you're not on the lookout for your symptoms (mine is similar to when I'm drunk. The tip of my nose numbs up) and some of the basics. Blue fingertips, numbness, euphoria, etc you'll get worse and worse and never notice a thing. It's really interesting training to actually see it happen and then see it happen to you on playback. You can't even add 2+2. It may have been what did in the Hunley crew back in the Civil War. Last time I was in Charleston the way it was set up they said they just never tried to get out. Hypoxia can paint a situation like that where you're living on a high, having a party celebrating your successful mission and be out before you know it.

Nap time. 3am alarm clocks suck!

[B4Buster]

This is what I never understood. If you can hold your breath for approx 2 minutes how can hypoxia take you out in seconds? I guess that while you hold your breath the air supply in the lungs keeps you going but if there's no air in lungs you pass out fast.

It has to do with the pressure (not being great enough?) to hold oxygen in your lungs.

icepac, why is 28K unreasonable? I'm not familir with the 421, but I know a guy who owns a C314. I believe the 314 has the same engines, and he routinely cruises in the 20K range. The aircraft is lighter, though...I'm just curious because I don't know the aircraft. Can it not climb that high?

[Shuffler]

  well that is a stupid rumor!

Evidently a news site put out a story about the doctor having several lawsuits against him and then the story was pulled. Who knows.

[Puma44]

Why dont aircraft have some kind of system to detect when oxygen levels are dropping in a cockpit and sound a alarm?

They do.......an altimeter, a (hopefully) well trained and attentive pilot, and for pressurized aircraft, a cabin pressure gauge with associated controls and warning alarms.

[Golfer]

There's no hard and fast rule that says incapacitation has to be from hypoxia or a pressurization malfunction either. Unfortunately with no CVR, the airplane in the ocean and no communication there may be very few facts or hard evidence available.

[Seanaldinho]

If you look at his track its kind of interesting how uniform those circles are. Now could the trim lead to such perfect circles?

[SFRT - Frenchy]

This is what I never understood. If you can hold your breath for approx 2 minutes how can hypoxia take you out in seconds? I guess that while you hold your breath the air supply in the lungs keeps you going but if there's no air in lungs you pass out fast.

Golfer described it pretty well, I myself had to do a couple of flights as low as 17/18K without oxygen, and despite the head hake was fairly fine, but I realized that's as far as I'd want to push it, doing my charts revision was .. painfully inefficient.
The way I see it, your body/cabin air pressure is much higher than outside. When you are exposed to rapid decompression initially the very low outside air pressure becomes the cabin air pressure. All the air inside your lungs follow the laws of physics and leave your lungs to equal the pressure. See it as cruising along and being punched in the guts then thrown into a swimming pool with two drumsticks showed into your eardrums ... and you have just a couple of seconds to find the 'scuba gear'.  

God knows what happened to this poor fellah. 421s have a cabin altitude warning light, that helps for insidious decompression if it's sneaky enough that your eardrums don't pick it up. My wild guess   is when he reached for his oxy mask maybe it was nicely packed up in a bag ... maybe he didn't have a mask but just a cannula ... maybe he had a mask but the oxygen bottle was closed. God knows, for even more "out of my butt' guesses, seeing his flight profile looks like he was in cruise when it happened with at least the autopilot on heading, but since he did a series of climb and descents after a while I don't think he had the altitude hold, just the "pitch hold'.

[pembquist]

This is what I never understood. If you can hold your breath for approx 2 minutes how can hypoxia take you out in seconds? I guess that while you hold your breath the air supply in the lungs keeps you going but if there's no air in lungs you pass out fast.

It isn't the amount of oxygen in the air that causes the problem it is the lack of pressure of the air, at a low enough pressure (im remembering 40,000 ft.) you can be breathing pure O2 and still become hypoxic.  The O2 diffuses across the membranes of your lungs, there has to be a positive pressure gradient for that to happen. 

[Babalonian]

This is what I never understood. If you can hold your breath for approx 2 minutes how can hypoxia take you out in seconds? I guess that while you hold your breath the air supply in the lungs keeps you going but if there's no air in lungs you pass out fast.

As I understand it as it's been roughly explained to me (and I'm no scientist or doctor), Oxygen has a natural physical tendency to want to travel from oxygen-rich to oxygen-depravated masses and also move from higher pressures to lower pressures.  More oxygen = the mass with higher pressure.  This plays into how lungs function at normal altitudes, Oxygen-deprived blood + Oxygen-rich air = good exchange.  Now, let's kick it up a few thousand vertical feet: Oxygen-deprived air + Oxygen-rich blood.... if you've taken a deep breath in post-depressurisation, it's already too late. 


One question I have to followup with my first "assumption", hopefully someone here knows with certainty - would this also play into why I've been told you're better off exhaling and holding rather than inhale and holding during a depressurisation?  Does it matter as it's different for every person?

[Golfer]

You're going to be "exhaling" alright but it's going to be into your shorts rather than out your nose.

[pembquist]

One question I have to followup with my first "assumption", hopefully someone here knows with certainty - would this also play into why I've been told you're better off exhaling and holdingrather than inhale and holding during a depressurisation?

There is this technique that some people advocate for climbing (slogging) in the mountains at high altitude:  Take a breathe, hold it and squeeze, let it out repeat.  I'm usually panting so I have never really tried it and I don't know if anybody has done real research on it.  The theory is that you raise the pressure and improve the diffusion into your body, what difference there would be in holding your breath with a lungful vs an empty lung I would think would be irrelevant except for the possiblilty of lung rupture as in holding your breath while ascending underwater.  I don't think its  very important, getting a mask on is what is important.

[clerick]

As I understand it as it's been roughly explained to me (and I'm no scientist or doctor), Oxygen has a natural physical tendency to want to travel from oxygen-rich to oxygen-depravated masses and also move from higher pressures to lower pressures.  More oxygen = the mass with higher pressure.  This plays into how lungs function at normal altitudes, Oxygen-deprived blood + Oxygen-rich air = good exchange.  Now, let's kick it up a few thousand vertical feet: Oxygen-deprived air + Oxygen-rich blood.... if you've taken a deep breath in post-depressurisation, it's already too late. 


One question I have to followup with my first "assumption", hopefully someone here knows with certainty - would this also play into why I've been told you're better off exhaling and holding rather than inhale and holding during a depressurisation?  Does it matter as it's different for every person?

http://en.m.wikipedia.org/wiki/Dalton's_law

There are two issues. First, you have a lack of oxygen. Second, there is the issue of a low partial pressure. Even if you had the same amount of oxygen, your body will "see" it as a lower concentration. Low O2 + low partia pressure = trouble.

[Tupac]

Cross post from another board

"The local LA papers now report that he had his medical license put on probation a day earlier. He was apparently a board certified obstretician, but his practice had shifted towards doing cosmetic procedures like liposuction and beauty related laser procedures. The medical board found that he had provided substandard care in 10 cases and misrepresented his qualifications in internet advertising. They put a restriction on his license and barred him from practicing outside of OB/Gyn. This kind of restriction typically puts someone out of business.

So, either he was trying to get away for a couple days after getting this devastating professional news and his pressuriziation controller failed, or he did this to himself."