John, John, et al,

 

And especially for the low altitude guys---

 

I don't know why I chose to respond to this title, perhaps it was the erroneous statement that there is some benefit in knowing your individual reactions to low O2.  Perhaps it is that the high altitude course and signoff is of little use to those of use that fly unpressurized and below FL18.

 

First, individual response to lack of O2 vary with not only altitude and dew point, but also state of exhaustion, weight, hydration, age, TOD, blood sugar level, etc.   Your response as a well toned 30 year old will be different than when you reach 55 years, are slightly overweight, wear glasses and don't sleep well. 

 

You need a rule about O2 user and stick to it while your head is still operating above 96% saturation.

 

One study I read looked at the response to the 13K foot elevation of an observation deck in Hawaii - both of that on visitors and regular workers.  The short result is that the workers exhibited different responses on different days, depending.................

 

My own experience (and the confessing of others) is that there can be an insidious degradation of memory/logic mental processing by some O2 deprivations.  I like to relate this to the sudden Swiss Cheese brain - most thinking is fine, there are some black holes.  Most of the time it does not result in death - just some ridiculous error.

 

My gear up in Sedona is a great example.  High humidity, high temps from IL to Santa Fe (8000 MSL, 10500 Dalt) had me on O2 at 12000 MSL approach to Santa Fe (stop because of hi mtn winds), 3 hr lay over waiting  for onset of evening and lesser winds - the last 45 min leg was with no O2 even thought the cannula was available on the next seat and the Oximeter around my neck was never used for a blood check.  Engine notations were clear and detailed over MO and approach to Santa Fe, notes taken on final leg to Sedona were garbled and childlike.  Sorry, I was unable to recognize that as a symptom.......I felt fine......  My Spinal nervous system flew the landing just fine - except no GUMPS, no three green check, no wheels.  A minor oversight.  I was tired, hungry and O2 deprived because of high density altitudes, etc. You should see the progression (degradation) of my notes...............

 

I understand that the military requires O2 from the ground if the extended flight is over 5000 MSL. 

 

My rule for long cross countries is similar to the military - I am old, always tired, overweight, grumpy, irritable and out of shape (unless you like the shape of apples with spindly legs).  I have no trouble donning the miniscule cannula and flipping the demand O2 system to supply each breath with a pulse above 5K.

 

If you fly below FL18, please consider studying the implications of O2 deprivation beyond that stuff spread around by the FAA.  And,  you don't need an endorsement.

 

Grayhawk

 

I added a CO GUARDIAN MODEL 353 + pressure alarm on my panel recently….good backup but not a cheap as a bag of chips.  BTW I recommend everyone take a high altitude training course…you really get to know your individual reactions to low Ox.

 

John C. Bohn

N28487 4P

Direct(cell) 503-887-2933

Home- 573-760-1090

---

From: marv@lancair.net [mailto:marv@lancair.net]
Sent: Wednesday, August 19, 2009 12:12 PM
To: lml@lancaironline.net
Subject: Re: What may have caused Kaboom at 16.5

 

Posted for John Hafen <j.hafen@comcast.net>:

 As I looked at the seal and its distance to the door frame at various places
 around the frame, I could see that it was fairly close all around (1/8 to
 1/4 inch) except for where it blew (right by the stick).  In that area,
 there was a gap of 1/2 inch to perhaps 5/8ths inch.  The thought is that as
 the seal rounds the 90 degree corner, it is already ³stretched² (because of
 the 90 degree bend) and has less expansion capacity than it would in a
 straight or flat area.  So the area was raised (see below) to narrow the
 gap, that hopefully will support the new $450 seal better (limit the
 expansion required).
 
 Meanwhile, based on posts from many of you, I¹ve decided to permanently hang
 a bag of corn chips from the middle of the Rosen Sun Visors.  If I ever lose
 cabin pressure again, I anticipate the bag will blow, providing both an
 audible and visual warning of cabin depressurization (my father¹s idea,
 actually). I¹m trying to figure out a way to have the exploding corn chip
 bag automatically turn on the emergency oxygen supply, but I haven¹t figured
 that our out quite yet.
 
 Cheers
 
 John Hafen
 N413AJ  IV (soon to be P) 160 hours