High altitude, non-turbo flight

[Pinecone]

On 12/25/2025 at 4:51 PM, N201MKTurbo said:

178 KTS on 10 GPH is pretty impressive.

At 50% power even

[DC_Brasil]

I constantly fly my J at 10 or 11K without O2. I carry a finger oxymeter and also have the garmin watch (although I take its o2 readings with a grain of salt). 

I never took it higher because I don't have O2 installed and I suspect I'd lose efficiency from the NA engine.

[Niko182]

The conclusion I’ve come to is that about 99% of people can fly a plane at 10 or 12 thousand feet without oxygen, and have no issues. However, I feel significantly better after 3 to 4 hours of flying at 10 to 12 ft using oxygen even periodically, so I elect to use O2. That doesn’t mean having it on the entire time but just using it every 45 minutes for 10 or 15 minutes. Obviously at 19,000ft that’s a different story and it’s worn the entire time, however I land significantly less fatigued and exhausted, and actually have energy to do things even after a day of 9 to 10 hours of flying.

a cheap O2 setup can be found used for 300 to 500 bucks and will improve those long travel days significantly. There is also the option to go up high, and avoid icing, turbulence, weather, and catch some pretty nice tailwinds. Just understand the downside is you can dig yourself deeper into a bad situation too. 
 

I guess all I’m saying is just because you can fly without oxygen at those altitudes doesn’t mean you need to. For an hour flight at 12,500, who really cares. If it’s 3 or 4 hours, the difference is pretty noticeable. 

[Skates97]

7 minutes ago, Niko182 said:

The conclusion I’ve come to is that about 99% of people can fly a plane at 10 or 12 thousand feet without oxygen, and have no issues. However, I feel significantly better after 3 to 4 hours of flying at 10 to 12 ft using oxygen even periodically, so I elect to use O2. That doesn’t mean having it on the entire time but just using it every 45 minutes for 10 or 15 minutes. Obviously at 19,000ft that’s a different story and it’s worn the entire time, however I land significantly less fatigued and exhausted, and actually have energy to do things even after a day of 9 to 10 hours of flying.

a cheap O2 setup can be found used for 300 to 500 bucks and will improve those long travel days significantly. There is also the option to go up high, and avoid icing, turbulence, weather, and catch some pretty nice tailwinds. Just understand the downside is you can dig yourself deeper into a bad situation too. 
 

I guess all I’m saying is just because you can fly without oxygen at those altitudes doesn’t mean you need to. For an hour flight at 12,500, who really cares. If it’s 3 or 4 hours, the difference is pretty noticeable. 

Agree completely. Typical cruising out west is 9,500-10,500' if VFR. We did that for years without oxygen and my sats always stayed in the lower to mid 90's. A few years back we bought a Inogen G5 Oxygen Concentrator. It doesn't cost anything to use it so we do anytime we're above 8,500' and there is a difference in how I feel and a noticeable difference in how my wife feels at the end of a 3-4 hour flight. My sats even when we've been at 11,000-13,000' with the oxygen split coming off the Inogen are 98-99.

[exM20K]

On 12/25/2025 at 3:51 PM, N201MKTurbo said:

178 KTS on 10 GPH is pretty impressive.

Pretty much the same in a TN, though the lower compression pistons are a little less efficient.

2700RPM = 310 hp STC, right? @Niko182 what sort of climb rate can you maintain through mid-high teens?

-dan

[McMooney]

have a trip to florida coming up next week, think i'll try some altitude flying, haven't been above 8000ish feet in a while

Edited December 31, 2025 by McMooney