Ceiling

[SPX]

Originally Posted by Taltruda

I don’t think a manufacturer can make a statement “approving” or “not approving” a product for use in an experimental. I’m sure Chevy or Subaru doesn’t “approve” their products for aircraft. Maybe I’m wrong here, but if you comply with applicable sections of part 91, I think you’re good, no?

Discussing cannulas, in the FAA Document titled Oxygen Equipment Use in General Aviation Operations

"They are restricted by federal aviation regulations to 18,000 feet service altitude because of the risk of reducing oxygen-blood saturation levels
if one breathes through the mouth or talks too much."

I am not sure if the regulation mentioned above is FAR 23.1447 or not.

[Captain Avgas]

Originally Posted by kaweeka

That came and went with requests every thousand feet untilI stopped at 24,000. My oxygen just couldn't keep up through a nasal cannula with SpO2 drifting down to 80%.

David

You might have been a bit lucky on that flight. I?m guessing that an SpO2 reading of 80% might have put you on the threshold of serious mental impairment. Hypoxia at altitude is very insidious...the worse it becomes the less you comprehend that you are suffering from it.

[Steve Iacoviello]

Originally Posted by Captain Avgas

You might have been a bit lucky on that flight. I?m guessing that an SpO2 reading of 80% might have put you on the threshold of serious mental impairment. Hypoxia at altitude is very insidious...the worse it becomes the less you comprehend that you are suffering from it.

?A bit lucky? is a bit exaggerated. SpO2 of 80% is what you would expect at 15,000 ft without supplemental O2. The FAA allows us to bring passengers to 15k without O2. Skydivers routinely go to 15K without O2. I am not saying that mild hypoxia is not present at 80% but we need to be reasonable.

On another note to the OP all I can say is very cool! Thanks for posting.

[rv8ch]

Hypoxia affects people differently. I recently watched this video and found it very interesting. https://eaa.org/Videos/Webinars/Lear.../6157994889001

[climberrn]

Originally Posted by Taltruda

and he should have gone back to phase 1 to expand them, but I don?t really know. Anybody care to chime in?

My operating limitations don?t specify any altitudes.

[Captain Avgas]

Originally Posted by Steve Iacoviello

?A bit lucky? is a bit exaggerated. SpO2 of 80% is what you would expect at 15,000 ft without supplemental O2. The FAA allows us to bring passengers to 15k without O2. Skydivers routinely go to 15K without O2. I am not saying that mild hypoxia is not present at 80% but we need to be reasonable.

The OP is not a passenger....he?s the sole pilot...big difference.

The FAA requires supplemental oxygen for pilots when flying above 12,500? for more than 30 minutes. 12,500? is equivalent to an Sp02 of 87%. The FAA further requires supplemental oxygen for pilots at any time above 14,000?. 14,000? is equivalent to an SpO2 of 83%.

An SpO2 of 80% is equivalent to 15,250? without supplemental oxygen and is regarded as the threshold of moderate hypoxia. Moderate hypoxia is where you start experiencing mental impairment. The extent of that impairment will vary between individuals depending on age and physical condition.

Incidentally the FAA requirement for supplemental oxygen over 12500? is actually quite generous...other aviation authorities feel that?s too liberal. In Australia for example CASA requires supplemental oxygen for a pilot over 10,000? in an unpressurised aircraft for any period of time.

The FAA also mandates a maximum altitude of 18,000? for nasal cannula oxygen supply...and there?s good reason for that. In this case the OP was up at 24,000?, well above the maximum. I?m thinking that this is not a practice that other pilots on VansAirforce should attempt to emulate.

[moosepileit]

Other points to consider- in my part of the DoD, if we dropped folks above 18000' we had to prebreath 100% O2 on a MASK, monitored by an extra technician.

If we flew unpressurized, max was FL250 unless waived.

Younger, better shape, got a chamber ride every 5 years. You have been to a chamber or simulator for hypoxia training, right?

Ask the glider guys if they go above 180 without a mask.

Just in case any of that is news, it's just some data on getting trained, paid and trusted to stay safe. Part 121 airline, we'd be on masks.

Wish someone would have asked if you were pressurized because talking into a mask sounds different than on a cannula. Most oxymiters have a 4% accuracy window.

[Caveman]

Thanks for posting David. Sam has a write up by Terry Jantz on his website about taking his RV6 to 26000 ft. With the RV 9 wing optimized for high altitude flight I wonder what you could really do if you took the same preparations. It wouldn’t be apples to apples unless flight conditions could be duplicated but it sure would be interesting. I wonder how much the horsepower affects the trial and if the wing can overcome the lower horsepower.

http://home.hiwaay.net/~sbuc/journal/high.html

[airguy]

Man, I'm tempted to go play with it....

I have had mine to FL190 a few times and once to FL210 just to see if it would get there - it did, but it's not a place I would normally cruise - the performance drops off too quick above 17,000'. Anything above that altitude is just for bragging rights or to clear a bit of weather.

But as just a "gee-whiz, let's go see" kind of flight, I'm real tempted. I think I'll wait until fall or winter and give it a shot. My airspace out here in west Texas is open enough that I don't think I'll have any grief from Center if I call them up ahead of time and explain the purpose of the flight.

I think I'll go up to 16-17k and reestablish Vy at that altitude prior to the trip and re-acquaint myself with that corner of the envelope.

[SPX]

One other area to check is how high your system was certified to under FAR 91.411. Once you have determined that number .. is it legal to operate above that altitude?