Harmful effects of low oxygen for passengers

Salty

Salty

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Salty
Let’s say I go up to 17,500 in an unpressurized plane, and I’m PIC wearing oxygen, but my passengers, one human, one canine, don’t use it. Is there any short or long term harm in spending a couple hours at that altitude without supplemental o2? I’ve done some googling, but I’m not getting a good feel for it. I would expect headache and lethargy to be short terms symptoms on arrival, anything worse than that?
 
Salty said:
Let’s say I go up to 17,500 in an unpressurized plane, and I’m PIC wearing oxygen, but my passengers, one human, one canine, don’t use it. Is there any short or long term harm in spending a couple hours at that altitude without supplemental o2? I’ve done some googling, but I’m not getting a good feel for it. I would expect headache and lethargy to be short terms symptoms on arrival, anything worse than that?
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https://pubmed.ncbi.nlm.nih.gov/21499843/
Besides from being illegal, think of it as a stress test for your passengers. Do you feel lucky? Think they will make it through without suffering detrimental effects? Following the rules might not seem like the fun or convenient course, but they really are there for our benefit, and we do a disservice to ourselves by not following them.
 
Salty said:
Let’s say I go up to 17,500 in an unpressurized plane, and I’m PIC wearing oxygen, but my passengers, one human, one canine, don’t use it. Is there any short or long term harm in spending a couple hours at that altitude without supplemental o2? I’ve done some googling, but I’m not getting a good feel for it. I would expect headache and lethargy to be short terms symptoms on arrival, anything worse than that?
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I'd say that you were a bad, bad PIC. Because dog.
 
Haven’t a number of veterinarians around here state that 8K is max for dogs?
 
Considering the regs say you must provide it for the PAX above 15k, I would say that you are probably going to be putting the AP on while you put the masks over people when you notice their strange behavior. So be prepared for that. I assume if you have an airplane that flies that high it has a decent autopilot that works? For reference most pressurized aircraft keep a cabin altitude of at least 10k ft... so anything above that you could probably expect sideeffects.

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FORANE said:
https://pubmed.ncbi.nlm.nih.gov/21499843/
Besides from being illegal, think of it as a stress test for your passengers. Do you feel lucky? Think they will make it through without suffering detrimental effects? Following the rules might not seem like the fun or convenient course, but they really are there for our benefit, and we do a disservice to ourselves by not following them.
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Please explain what rules would be broken with what I described? None that I’m aware of. I did not say it would not be provided, I said if it was not used.
 
murphey said:
Haven’t a number of veterinarians around here state that 8K is max for dogs?
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I haven’t seen this, that’s why I’m asking. References? I thought 10k was typical for pressurized cabins and pets fly in them all the time.
 
FORANE said:
https://pubmed.ncbi.nlm.nih.gov/21499843/
Besides from being illegal, think of it as a stress test for your passengers. Do you feel lucky? Think they will make it through without suffering detrimental effects? Following the rules might not seem like the fun or convenient course, but they really are there for our benefit, and we do a disservice to ourselves by not following them.
Click to expand...
Aside from rules that I don’t think exist, I’m asking what they could experience. I can imagine all sorts of things that won’t actually happen, I’d like to know what the reality is.
 
And thanks POA for stepping up once again to try to make someone feel bad for asking a question. I wouldn’t have asked the question if I didn’t care. A bunch of meaningless “you’re a bad PIC that’s breaking the law” posts are pretty useless in educating someone about the subject they asked about. As I said, I did some research first and didn’t find anything helpful other than, eventually you’ll die if you go high enough, or the FAR regs, neither of which serve to answer the question.
 
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Salty said:
Aside from rules that I don’t think exist, I’m asking what they could experience. I can imagine all sorts of things that won’t actually happen, I’d like to know what the reality is.
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91.211 OK, semantics of provided vs used.
https://www.govinfo.gov/content/pkg/CFR-2012-title14-vol2/pdf/CFR-2012-title14-vol2-sec91-211.pdf

Have you been up that high before? Or even to 14k without o2 before? People tolerate it differently, but I know I would not want to go anywhere near 17.5 without o2. You can google the common symptoms restlessness, confusion, headache, memory loss, shortness of breath, tachycardia, tachypnea... You are correct in the belief there are all sorts of potential complications that remain unlikely. The incidence of complications will vary with the individuals underlying health condition.

I doubt the respondents here intended to berate you. Our posts reflect concern for the issue discussed. What good can come from not using o2 at that altitude?
 
FORANE said:
91.211 OK, semantics of provided vs used.
https://www.govinfo.gov/content/pkg/CFR-2012-title14-vol2/pdf/CFR-2012-title14-vol2-sec91-211.pdf

Have you been up that high before? Or even to 14k without o2 before? People tolerate it differently, but I know I would not want to go anywhere near 17.5 without o2. You can google the common symptoms restlessness, confusion, headache, memory loss, shortness of breath, tachycardia, tachypnea... You are correct in the belief there are all sorts of potential complications that remain unlikely. The incidence of complications will vary with the individuals underlying health condition.

I doubt the respondents here intended to berate you. Our posts reflect concern for the issue discussed. What good can come from not using o2 at that altitude?
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One of my passengers has stated that they have flown with others that high without oxygen. They just slept. Part of this discussion is to have a good response to that, part of it is to get a better understanding. Part of it is due to a pet that can’t get o2, or at least I haven’t figured out how yet.
 
Here’s a side question, but very relevant. Why do the regs only require o2 to be made available and not used above 15k, if it is a serious health risk? Why doesn’t it even need to be made available at 14k if it’s a serious health risk?
 
Just look up info on people who mountaineer at these altitudes fairly regularly if you’re looking for long term effects.

Short version: Generally ... none. A handful have pulmonary effects that can be fatal quickly or cause permanent damage if not treated quickly.
 
I was going to say, they probably will just go to sleep. If you want to experience this for yourself, the major air shows usually have chamber where you can experience hypoxia. That said, I would not do this to anyone I liked, in fact, I wouldn't do it to someone I didn't like either.
 
Well increasing hypoxia will lead to increased confusion. What stops a passenger getting disoriented or unruly, grab for a door handle. Magnified for an older person. Magnified for a smoker. Magnified at night.
 
Salty said:
One of my passengers has stated that they have flown with others that high without oxygen. They just slept. Part of this discussion is to have a good response to that, part of it is to get a better understanding. Part of it is due to a pet that can’t get o2, or at least I haven’t figured out how yet.
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Essentially the passengers could potentially develop altitude sickness or acute mountain sickness. https://en.m.wikipedia.org/wiki/Altitude_sickness

The chronic effects of high altitude are not going to come about in a few hours.

There is a great deal of variability in human responses to this kind of change. Some of the effects of AMS are quite serious, including cerebral and pulmonary edema though one usually sees warning signs. I can’t say that I would recommend messing around with this.

I cannot comment directly on the dog, but would expect some might respond similarly to humans and be subject to similar risks.
 
Pets:
There is no hard and fast rule of how high they can go.
No regulation and no industry-wide universal acceptance of how high.
Pets are like humans.. in that regard - some can take higher altitudes than others.
99%+ would have no problem at 10K.
But throw in cardiac disease, or COPD, or a hot cabin with a brachycephalic, you gotta problem.
Masks. If you really think it necessary. If you can get a pet to accept them.
Most masks have vast openings in the sides where the oxygen can escape. So you end up shooting oxygen 'past' their intakes. They are getting a whiff of it. I would have to see PO2 data to accept that they do anything. At work, we use a sealing mask which is connected to a rebreathing bag. With flow rates high enough, we can raise the O2 from 75 to 90 but the pet has to have a functioning internal O2 transfer system, has to be either sedated or sick with something that makes it accepting of a sealing mask ("They're trying to suffocate me!")
I guess you could hire one of us to induce them with propofol, intubate them and maintain them on iso or sevo lol 99% O2 guaranteed!)
I recently heard 2nd hand of a study of "Oxygen chambers" for pets in which you'd think they couldn't be anything other than 100% but apparently it takes insanely high flow rates to budge a low O2.

An older AOPA members only article but not much has changed.

https://www.aopa.org/training-and-s...ing-with-children-and-family-flying-with-pets
 
Salty said:
Here’s a side question, but very relevant. Why do the regs only require o2 to be made available and not used above 15k, if it is a serious health risk? Why doesn’t it even need to be made available at 14k if it’s a serious health risk?
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Planes don't crash if the passengers get hypoxic or lose consciousness. So if they don't want to use oxygen that's available, the FAA isn't going to make them.
 
Lindberg said:
Planes don't crash if the passengers get hypoxic or lose consciousness. So if they don't want to use oxygen that's available, the FAA isn't going to make them.
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Planes don’t crash if passengers don’t wear their seatbelts either.
 
Lindberg said:
Planes don't crash if the passengers get hypoxic or lose consciousness. So if they don't want to use oxygen that's available, the FAA isn't going to make them.
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Actually, a better counter argument is: why do you have to provide it at 14k then?
 
Salty said:
Planes don’t crash if passengers don’t wear their seatbelts either.
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The PIC's responsibility is in notifying passengers to fasten their seatbelts. Very similar in spirit to the requirement to provide oxygen.
 
dmspilot said:
The PIC's responsibility is in notifying passengers to fasten their seatbelts. Very similar in spirit to the requirement to provide oxygen.
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I don’t think that ends the matter. Remember that the PIC is responsible for the safe and lawful operation of the aircraft. The regulation says...

(3) Except as provided in this paragraph, each person on board a U.S.-registered civil aircraft (except a free balloon that incorporates a basket or gondola or an airship type certificated before November 2, 1987) must occupy an approved seat or berth with a safety belt and, if installed, shoulder harness, properly secured about him or her during movement on the surface, takeoff, and landing.
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Passengers are required to wear the belts. Seems to me the pilot is responsible to ensure compliance.
 
FORANE said:
91.211 OK, semantics of provided vs used.
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I don’t think it’s semantics at all, it’s an important and presumably intentional distinction. You don’t have to force your passengers to put the cannulas or masks on, but do have to make it available for their use. Some may choose not to, and that’s okay from a PIC perspective.
 
Salty said:
Actually, a better counter argument is: why do you have to provide it at 14k then?
Click to expand...

I wonder if there actually was some data regarding this limit. I believe the the regulations for pilots were based on some older hypoxia experiments and the likelihood of problems.
 
Half Fast said:
Passengers are required to wear the belts. Seems to me the pilot is responsible to ensure compliance.
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Believe thats only law in commercial ops.

Not that I’m departing until you put it on... or you can get out...

But no requirement that they use it in private ops I don’t think.
 
denverpilot said:
Believe thats only law in commercial ops.

Not that I’m departing until you put it on... or you can get out...

But no requirement that they use it in private ops I don’t think.
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We operate under part 91, do we not?

91.107
(3) Except as provided in this paragraph, each person on board a U.S.-registered civil aircraft (except a free balloon that incorporates a basket or gondola or an airship type certificated before November 2, 1987) must occupy an approved seat or berth with a safety belt and, if installed, shoulder harness, properly secured about him or her during movement on the surface, takeoff, and landing.
Click to expand...
 
Zeldman said:
I live at 6500 feet. Should I go on oxygen at night.??
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Unable to answer from the information provided. Have you had a sleep study?
The above is a somewhat flippant response to what I assume is a rhetorical question. Folks who live at elevation acclimate to the altitude within a couple of weeks at the altitude.
 
RussR said:
I don’t think it’s semantics at all, it’s an important and presumably intentional distinction. You don’t have to force your passengers to put the cannulas or masks on, but do have to make it available for their use. Some may choose not to, and that’s okay from a PIC perspective.
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My use of semantics was in reply to post #6 from the op. Perhaps I should have clarified, sorry for the confusion.
 
Not everyone handles hypoxia the same. The classic symptoms are euphoria, sluggishness, and etc. When I went through the altitude chamber I could realize how stupid I was becoming (we were doing the standard acuity tests so it was obvious) which is disconcerting and started to have a hot flash. A hot flash in your early twenties is not enjoyable.

Everyone reacts differently and starts to react at different O2 levels. Best not to run the risk and stick to the regs as a minimum and aim to provide oxygen well before that.
 
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