High Altitude Flight test

4

4RNB

Line Up and Wait
PoA Supporter
Joined
May 24, 2016
Messages
962
Display Name
Display name:
4RNB
For reference: https://www.airplains.com/cessna172-180hp

I would like to experience my plane at higher altitudes prior to doing some West Coast flying. I've been to 9,000 before. We have bottled O2, a finger probe SpO2 monitor, and the O2 is delivered with little bursts upon inspiration. I'd like to just go climb one day, see how the plane performs while monitoring my sats on oxygen.

I'm debating taking a safety pilot, not a non pilot spouse, though she is a nurse.
Thoughts?
 
Last edited:
MauleSkinner said:
If you’re monitoring things, why do you need a safety pilot?
Click to expand...

Im just trying to think things thru on the ground before doing this. Reading about high altitudes misadventures online has me consider it.
 
Physiologically you’re probably ok through 15k for a short stint, unless you have any health issues. If you’re super worried, keep a touch of nose down trim and keep your shoulder harness tight.
 
I took a 207 up to 12,000 once without O2 and had no problems, except for the climb rate getting lower the higher I went.

As for a safety pilot, might as well. I mean it is more fun flying with other folks than flying alone.
 
I’ve been to 13-14K several times with no apparent issues. The usual increased heart / breath rate but that was about it. Typical SE FW you’ll see some sluggish in the control response and mediocre climb rates. Seen similar with flying RW at higher altitudes.
 
Tolerance here varies a lot - age, health, genetics. . .some people have symptoms well below 15K; others do well enough at 20K, at least for a few minutes at a time. Personal symptoms vary, too - some folks have pronounced warnings, like tingling, nausea, vision changes. Others have much more subtle indicators - my face itched a bit in the altitude chamber after the RD, but that was about it - but I was in my 20s and cardio fit. . .
 
I've been as high as 11,500 in a Cessna 172 with no oxygen or monitoring for a cross-country many times. Usually did have a 2nd pilot with me, flying under the hood/safety pilot. We agreed ahead of time if either of us started laughing or acting odd we would descend. Never had an issue. Not sure where you live, but if you were nearby I'd be game to be your guinea pig.
 
Did Corona pass E bound in a 150hp 172M @ 14,500. Mixture control seemed a little squirrely/touchy was the only thing I noticed.
 
You have O2 available and an SpO2 monitor--go fly with or without company. If you take someone have them on a monitor too.
 
It's important, critical, that you have a clear understanding of hypoxia. I have experienced it twice. Once at 12,000 and once a little higher. Absolutely take a CFI with you and here's why.

In both my cases, I slowly and without noticing at first, I just started feeling great! The plane felt great, the sky was beautiful and I began to realize what a great pilot I was. I just thought this very comfortable feeling was because the world looked so beautiful from up here.

In both cases, a part of my brain began to realize that only a few moments before I had been somewhat concerned about how high I was. Yet for no good reason that anxiety had disappeared. Fortunately, I was still aware enough to realize I was hypoxic and needed to stop climbing. Once I got down around 9,000 feet I came to the realization that I was not, in fact, the greatest pilot in the world.

While everyone reacts differently at different altitude's, hypoxia can be insidious. It can also give some the sense of feeling great, as it did for me. In the state I was in part of me just wanted to keep climbing. If I had done that there would have been a good chance that I would have simply passed out.

Just because some have climbed to high altitudes with no affect, does not mean you will be ok. Many have significant effects at lower altitudes. I think it's a great idea to find out your limits. I also think it's a great idea to have a CFI in the plane to help ensure you do it safely - at least the first time. Hypoxia can be a real danger.

I now carry a can of Boost O2 in the plane at all times. When I'm as low as 8000 feet for an extended time I start feeling uncomfortable. I will take a it or two off the can and I can feel the relief. If I'm going to be up at 9000 for some time I make sure I have the can in my lap and take a hit every few minutes. I am older now and the reduced O2 affects me more than some.
 
Last edited:
Domenick said:
You have O2 available and an SpO2 monitor--go fly with or without company. If you take someone have them on a monitor too.
Click to expand...
And if you have a (pilot) buddy with you, each of you can, in turn, take off your oxygen for a bit and identify your initial hypoxia symptoms.
 
If you have an opportunity to take a session in the FAA Portable Reduced Oxygen Training Enclosure (PROTE) definately take advantage of it. I believe they will be at OSH again this year, and you can look on faasafety.gov for other sessions. Its a great way to get familiar with your own hypoxia symptoms.
 
After looking at the winds and temps aloft, I think I will add extra clothes, gloves, and a hat to my list.
 
images
 
4RNB said:
I’ve never been at 17,000 feet better safe than sorry
How does your heater work at 17,000?
Click to expand...
What are you flying that you're going to be able to get up to 17K feet without flying at 50fpm forever?
 

UngaWunga thanks for posting the video.​

This is my go to video that they showed me when I when through the altitude chamber.

The theme here is it is good to be cautious with hypoxia.
The common theme I see is that the brain get stuck in a loop... i.e.
...everything becomes a 4 of spades.
...all the shape are now squares
...Whatever you were doing you probably will just keep doing it, unable to make a decision.


Most racing glider pilots I know start using O2 at 5000'. Not necessarily because the need it, but because it is a cheap, legal, performance enhancing drug that gives them a slight edge (better decisions) than the pilot not using O2.



Below is likely the result of a O2 system that wasn't setup/working properly. The pilot never intended to leave the vicinity of the airport, was just going to be a high altitude (16,000ft) local flight. Once at altitude he flew out of range of the airport.
overflew another airport he was familiar with then flew out of range of that airport to a point where the only suitable landing area he could reach was the lake. He remembers the flight but had no explanation for how he could made such poor decisions, until about 2 month after the accident he was discussing the flight with another pilot and it came out that the pilot was unaware that the Cannula he was using (he had borrowed it from his power plane) was incompatible with the O2 system in the glider. A bit more research indicated that as a result he likely getting very little oxygen.

1714164529484.png

I had an O2 system fail on me once as well, it failed after the flow indicator (leaking) so I had no indication that it wasn't working. I flew at about 12,000-13,000 feet for about an hour, than got up 16,000 feet. At 16,000 feet I began to notice the tunnel vision and just not feeling very good. A bit of checking the O2 system I found the broken O2 line and was able to repair it but I was now an hour and 1/2 away from the airport. I turned around a flew back to the airport, landed and put the glider away and then took a long nap.

2 years ago while experimenting with an ATC clearance for a Glider and my new ADS-B system, I accidently set the state altitude record. I had no idea the record was that low and had previous been set in 1962.
1714165057416.png

Brian
CFIIG/ASEL
 
Last edited:
Owning a 182 Turbo, I fly routinely 16,500 or 17,500 with oxygen of course. The draggy 182 manages 165 kTAS up high. Up that high with tail winds not uncommon to get smooth air and 200+ MPH ground speed. Other benefit is literally no traffic as everything else 12K or lower or 25K or higher.

Keep an eye on density altitude more than absolute altitude when metering oxygen as needed. Highly recommend a finger oximeter to measure blood oxygen %. They are inexpensive.
 
Last edited:
Zeldman said:
I live a at 6500 msl, should I use oxygen at night.??
Click to expand...
Going from 780' in Illinois to 8500'+ in New Mexico over a 24 hour span, then start hiking at 5am..I have no problems. But I know more than a few guys that are taking the next day or two off. Definitely an acclimation for most. Maybe I should bring some oxygen to camp?

I do remember reading an article I think by Dr. Brent Blue about the difference oxygen makes with your eyesight at night, even at lower altitudes.

Physiologically you'll probably be fine. But what was eye opening to me the first time I was up "high" was the anemic climb rate and mushiness of the controls.
 
brcase said:

​

Most racing glider pilots I know start using O2 at 5000'. Not necessarily because the need it, but because it is a cheap, legal, performance enhancing drug that gives them a slight edge (better decisions) than the pilot not using O2.
Click to expand...
Not sure where that leaves me; my driveway is at 7400.
 
I live near sea level and use O2 all the time…..at the ambient partial pressure. My father, an old school anesthesiologist, who instructed the airway section of ACLS courses would open by saying “Oxygen is the most lethal agent we use…..it is uniformly fatal if delivered in 1 part per billion.” ;)
 
If you have an O2 sensor, just go ahead while monitoring. Start descending if the O2 drops to the low 90s.

One thing that is helpful at high altitude is called pressure breathing. Exhale more completely than you do with normal breathing, and same with inhaling. Not quickly, it's not hyperventilating. It's much deeper and a bit slower than normal breathing. You can read more about pressure breathing on mountaineering sites. Personally, I find that it works - I see O2 levels jump 5-10% within one minute of doing it.

Also, at high altitude the air is dry and you lose more moisture with every exhaled breath. This can worsen high altitude symptoms. Make sure to have water available and drink it.
 
Mount Everest has been climbed without oxygen, but it's rare. As of January 2024, only 221 people have summited Everest without supplemental oxygen. Reinhold Messner and Peter Habeler were the first to do so on May 8, 1978, by speeding up their climb and spending as little time as possible at the summit.

29,043 feet
 
Well I just went above 13000, 90 mph was still getting 3-400 fpm climb.
Sats to 84 on mountain high system.
I wonder if it would have been better on continuous oxygen.
I had on 3 layers, was glad for it as my top vents never fully close. One spit out something, ice?
Carb heat required, or it was used.
Man did that engine run cooler up higher.
 
4RNB said:
Well I just went above 13000, 90 mph was still getting 3-400 fpm climb.
Sats to 84 on mountain high system.
I wonder if it would have been better on continuous oxygen.
I had on 3 layers, was glad for it as my top vents never fully close. One spit out something, ice?
Carb heat required, or it was used.
Man did that engine run cooler up higher.
Click to expand...
If "Sats to 84" means your blood O2 saturation level was 84%, that is too low and unsafe for flying, at risk of impaired judgement and cognitive function.
 
MRC01 said:
If "Sats to 84" means your blood O2 saturation level was 84%, that is too low and unsafe for flying, at risk of impaired judgement and cognitive function.
Click to expand...
Thanks.
Note the RN in my screen name...I'm well aware, all part of why I posted this topic and am asking about continuous O2 vs a lil bit on inhale with the mountain high system.
 
RockyMtnFlyer said:
Not sure where that leaves me; my driveway is at 7400.
Click to expand...

Yes, about 60% of my glider flying is off a runway at 6000ft. I do set my MH system to turn on at 10,000 feet so I can turn it on before launching and not having it beeping at me.

If launching below 5000ft I set it for 5000ft. I have found that when flying between 5000-12000 feet, my bottle will probably last me 50hrs of flying time. When flying between 12000-18000 feet it last about 25 hrs.

I think the generally accepted interpretation of the 5000 ft oxygen recommendation is to use 5000ft above the altitude you are acclimatized to. Using an Oximeter is a good idea to verify.

Brian
 
crashton said:
If you have an opportunity to take a session in the FAA Portable Reduced Oxygen Training Enclosure (PROTE) definately take advantage of it. I believe they will be at OSH again this year, and you can look on faasafety.gov for other sessions. Its a great way to get familiar with your own hypoxia symptoms.
Click to expand...
Do you need to sign up in advance?
 
I'd imagine a real chamber ride like I did years ago is even better in some ways. Looks like they might still have that in the program too.... https://www.faa.gov/pilots/training/airman_education/aerospace_physiology

Oh I misread in my quick glances....maybe this is only at OKC. I thought I read something that still said chambers at military bases...but I'm not seeing that now.

Back when I did it, the program offered PPL holders to visit a nearby military chamber that they would open up every once in a while. I did my ride at Langley AFB
 
Manu years ago I did a skydive jump from 20,000 ft msl. We had oxygen above 12k and at 18500 I decided to take the mask off temporarily go are what it would feel. I started to feel like I had a few beers, but the most telling symptom was my vision slowing tunneling... I put the mask back and everything went back to normal in 5 secs.
 
You must log in or register to reply here.
Back
Top