TIME TO PASSING OUT

Submitted by Anonymous on

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From: PETER WILLIAMS <peterpawaviation [at] hotmail.com>
Sender: <marv [at] lancaironline.net>
Subject: TIME TO PASSING OUT
Date: Mon, 08 Sep 2014 08:10:47 -0400
To: <lml [at] lancaironline.net>
There are many individual variations of hypoxia, even within the same person.


Generally, old age tends to reduce the efficiency of the pulmonary system,

] Smoking drastically reduces oxygen intake efficiency, and  reduce tolerance by 3,000-6,000 feet
A rapid decompression can reduce the these numbers by up to 50 percent
AND,
less time is available for rational thinking,



The table below reflects various altitudes with the corresponding average time til unconscious  are for an individual at rest


Altitude in Flight level Time of Useful Consciousness Altitude in meters Altitude in feet
FL 150 30 min or more 4,572 m 15,000
FL 180 20 to 30 min 5,486 m 18,000
FL 220 5-10 min 6,705 m 22,000
FL 250 3 to 6 min 7,620 m 25,000
FL 280 2.5 to 3 mins 8,534 m 28,000





time to passing out

Submitted by Anonymous on

From: Jon Hadlich <aisystems15 [at] gmail.com>
Sender: <marv [at] lancaironline.net>
Subject: time to passing out
Date: Tue, 09 Sep 2014 09:40:36 -0400
To: <lml [at] lancaironline.net>
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My question to all the pressurized guys flying the flight levels is don't you carry emergency oxygen? I would think that would be the first thing to do with a pressurization problem as well as descending? I'm not a flight level guy yet, but I've been on flights in the flight levels and was briefed on emergency procedures for decompression.

Put the oxygen on and go down.


--

AI Systems
(541)815-7381

time to passing out

Submitted by Anonymous on

From: Doug Johnson <lancair1 [at] bellsouth.net>
Sender: <marv [at] lancaironline.net>
Subject: RE: [LML] time to passing out
Date: Tue, 09 Sep 2014 13:27:01 -0400
To: <lml [at] lancaironline.net>
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Jon, we certainly should be carrying O2 as backup. The biggest problem in these events revolves around one of the following: 1) the loss of cabin pressure is gradual, and unrecognized for some time, 2) there is no O2 in the system (leaks, prior use, etc.—we should all have the gauge level check on our preflight list); the system doesn’t work (loose hoses, etc.), 3) relating to the first item, if the pressurization loss goes on for a while before recognized, the pilot can lose common sense before consciousness—not remembering which way to turn the valve on the tank under the seat, forgetting how to program the auto-pilot for lower altitude, be more concerned with high fuel consumption down low (turbine guys) leading to poor prioritization of needs (save gas vs. save life) and poor cockpit resource management. As pointed out in other posts, we lose tolerance to hypoxia as we age, as well…

 

I have a rule that if flying above FL 200, I always have the mask out and dangling around my neck; and yes, I always check the gauge under the seat when I climb in…

 

Douglas W. Johnson, MD PA

Ret. USAF Flight Surgeon, in another life…

 

My question to all the pressurized guys flying the flight levels is don't you carry emergency oxygen? I would think that would be the first thing to do with a pressurization problem as well as descending? I'm not a flight level guy yet, but I've been on flights in the flight levels and was briefed on emergency procedures for decompression.

Put the oxygen on and go down.

--

AI Systems

(541)815-7381