Tom,

 

Ok, you asked for regulation. It would seem that's it. I won't search for it now, but because I am well acquainted with creeping hypoxia, there is information that relates to density altitude (just like the engine), age, physical condition, etc. and the effect on O2 absorption, and where gas pressure differentials start to resist the transfer of O2. Thus, in certain environments a mask is required to force the O2 pressure high enough to cause the transfer to occur in the lungs.

 

The FAA requirements are minimal. When the O2 saturation levels drop to around 89%, an individual is impaired. Night vision is dramatically affected by even minimal reduction in blood O2 saturation.

 

Perhaps you should experiment by getting a pulse oximeter (http://www.aeromedixrx.com/Nonin-9590-Fingertip-Pulse-Oximeter.html) and measure how altitude affects your personal O2 levels.

 

BTW, recognition of impairment may be hindered by euphoria.

 

Scott

 

PS My 700 MSL home location gives my old fat body O2 results that vary from 95% to 97%. Young healthy folks should be showing 99%-100%.

Scott,

Yea, I read that of course, but sorry, I don't see it. Neither "canula" nor "18,000 feet" is even in that para. The only time "mask" is mentioned is with reference to pressurized A/C flying above FL350. Don't think any Lancair flies that high.

Is there a reference that does apply? BTW neither "canula" nor "cannula" even appear in Parts 21, 23 or 91 except in Part 23.1447, the one mentioned before that doesn't apply to us.

Tom T.

§ 91.211 Supplemental oxygen.

(a) General. No person may operate a civil aircraft of U.S. registry—

(1) At cabin pressure altitudes above 12,500 feet (MSL) up to and including 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen for that part of the flight at those altitudes that is of more than 30 minutes duration;

(2) At cabin pressure altitudes above 14,000 feet (MSL) unless the required minimum flight crew is provided with and uses supplemental oxygen during the entire flight time at those altitudes; and

(3) At cabin pressure altitudes above 15,000 feet (MSL) unless each occupant of the aircraft is provided with supplemental oxygen.

(b) Pressurized cabin aircraft. (1) No person may operate a civil aircraft of U.S. registry with a pressurized cabin—

(i) At flight altitudes above flight level 250 unless at least a 10-minute supply of supplemental oxygen, in addition to any oxygen required to satisfy paragraph (a) of this section, is available for each occupant of the aircraft for use in the event that a descent is necessitated by loss of cabin pressurization; and

(ii) At flight altitudes above flight level 350 unless one pilot at the controls of the airplane is wearing and using an oxygen mask that is secured and sealed and that either supplies oxygen at all times or automatically supplies oxygen whenever the cabin pressure altitude of the airplane exceeds 14,000 feet (MSL), except that the one pilot need not wear and use an oxygen mask while at or below flight level 410 if there are two pilots at the controls and each pilot has a quick-donning type of oxygen mask that can be placed on the face with one hand from the ready position within 5 seconds, supplying oxygen and properly secured and sealed.

(2) Notwithstanding paragraph (b)(1)(ii) of this section, if for any reason at any time it is necessary for one pilot to leave the controls of the aircraft when operating at flight altitudes above flight level 350, the remaining pilot at the controls shall put on and use an oxygen mask until the other pilot has returned to that crewmember's station.

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