I have never replied to any posting to the LML but I think this is one time I can really offer some insight. I have 17 years of military flying experience -- I flew as a door gunner on CH-46 Helicopters (800 hours) in the USMC and as loadmaster on C-130H2 in the US Air Force (2500 hours), with the latter being a pressurized aircraft. Furthermore, I also have another 2000 hours as pic in pressurized aircraft -- Beechcraft Dukes and Lancair 4P's.
As part of my C130 qualification, I was required to go through the pressurization chamber every 4 years. The purpose of the pressurization chamber is to identify our individual hypoxic symptoms. For some people it becomes confusion and other become nauseous. We attended a ground school prior to entering the pressurization chamber so that we would stay current on what hypoxia is, how it happens, and what are the symptoms -- we didn't just walk into the pressurization chamber. While in the pressurization chamber we were required to execute repetitive tasks while they instructor drop the "aircraft" pressure. As I just wrote, confusion is the most common symptom for most people but nausea can occur in others, too. As we conducted our repetitive tasks it soon became clear that the simplest tasks were becoming increasingly difficult to concentrate and execute as well as remembering the next task. We had been trained to recognize the symptom so the next immediate thing to do was to go on oxygen.
Hypoxia is insidious so it is very, very important that everyone who flies a pressurized aircraft understand their individual symptoms. Ultimately, if you don't recognize the symptom and take corrective action, you will lose consciousness. At the altitude this gentleman was flying he only had seconds to recognize his symptoms before he was unable to think and act coherently -- you won't get two minutes to recognize your hypoxic symptom. It's easy to speculate on what he did or didn't do but I suspect that he wasn't aware of his own symptoms as they relate to hypoxia and he quickly went into a state of confusion before he could make coherent decisions.
My recommendation is that EVERYONE who flies a pressurized aircraft experience the pressurization chamber -- not just once -- but on a regular interval because as you age, even if you are very fit, the onset of hypoxia will happen quicker resulting in the symptoms will occurring sooner. It’s imperative that a pilot know when they’re suffering from hypoxia; otherwise, they’re rolling the dice when they fly a pressurized aircraft at the flight levels.
Jay Hamilton
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From: Lancair Mailing List [mailto:lml@lancaironline.net]
Sent: Tuesday, September 09, 2014 5:00 AM
To: Lancair Mailing List
Subject: lml Digest #4737
Lancair Mailing List Digest #4737
1) Prop Boots
by "jwilless@itd-nc.com" <jwilless@itd-nc.com>
2) 28,000 feet NO WHERE TO GO BUT DOWN
by PETER WILLIAMS <peterpawaviation@hotmail.com>
3) TIME TO PASSING OUT
by PETER WILLIAMS <peterpawaviation@hotmail.com>
4) 28,000 feet NO WHERE TO GO BUT DOWN? #2
by PETER WILLIAMS <peterpawaviation@hotmail.com>
5) FLIGHT LEVEL REALITY OX MASK
by PETER WILLIAMS <peterpawaviation@hotmail.com>
6) Re: Right Fuel Tank Probe
by <marv@lancair.net>
7) Crossbow ADAHRS Manual
by Robert R Pastusek <rpastusek@htii.com>
8) Re: Crossbow ADAHRS Manual
by <marv@lancair.net>
9) Re: Crossbow ADAHRS Manual
by "Jay Phillips" <jayph@fastairplane.net>
10) Re: Crossbow ADAHRS Manual
by Steve Richard <steve@oasissolutions.com>
11) Re: Crossbow ADAHRS Manual
by John Barrett <2thman1@gmail.com>
12) Re: Crossbow ADAHRS Manual
by Robert R Pastusek <rpastusek@htii.com>
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