On Wednesday, October 2, 2019 at 7:17:16 AM UTC-4, Tango Eight wrote:
On Tuesday, October 1, 2019 at 3:44:11 PM UTC-4, RR wrote:

The legalitys are not so clear [...]

I should have been more specific, the legalities in experimental aircraft (many if not most of our gliders) are not so clear.

And I am sorry if I implied a recommendation. I am just speaking of my own experience (18 years of diamond and Lenny climes) accompanied with, pulse oximeters (from back when they were expensive) and backup systems at hand.

I totally agree with T8 about not scrimping on the Ox. No using the oxisaver flow levels. But for me, with full beard and mustache, I know what is being delivered to my nose, where I would be concerned about leakage from a mask.

Ox at altitude is not something to take lightly. And single place aircraft require real diligence in acquiring the knowledge about your personal reaction to hypoxia. Know your symptoms, and learn to react quickly.

One thing that is very important to know is the Ox saturation curve has a "kink" in it at 25k. Flights to 24k are like scuba diving, flights above are like cave diving. You need to have redundant systems. Everyone knows climbers have ascended Everest without Ox and think they can descend if something goes wrong, but the amount of "useful conciseness" you have above 27k is measured in seconds not minutes.

RR



FAR 23.1447 spells it out (for certificated aircraft). Above 18K the requirement is for a mask that covers nose and mouth.

The fact that some people can get away with a cannula at 26K (once) does not mean that this is a sound practice. We've had two hypoxia incidents (that I know of) at Mt Washington due to pilots emulating certain old timers. Physiology varies. Physical fitness doesn't seem to be a factor (in fact casual observation suggests the reverse :-)).

T8