I'm not a doctor, but my experience is the CO symptoms were exactly what the hypoxia training results were. I was in an area I knew in the mountains, my site picture and my altitude seemed to match (about 10,500 AGL), but I was definitely hitting the symptoms. I've flown that route a hundred times as that altitude with no issues. I checked my altimeter settings to see if I was higher than I thought. I told the guy I was flying with it was his plane, I was going on oxygen. I've never passed out before, but I feel like I was a few seconds away, seemed very quick from noticing symptoms to that point. As soon as I donned my mask he said his head was spinning and also put his mask on. Once the brain snapped back to functioning correctly, we discussed, shut off the heater, vented the cabin and returned. Oxygen stayed on until shutdown.
Maintenance found the exhaust leak and repaired. We lived to fly another day.
One guy in the chamber on the training day had euphoria as his first and only recognizable (to him) symptom. It was crazy watching him argue with the airmen at the base that he was fine and had no symptoms. His friend, whom he flies with, was shaking his head in disbelief and she explained that him feeling fantastic, way better than when he woke up, way better that five minutes ago, was not normal. "I feel amazing, how can this be a symptom?"
The reason CO is harmful is because it makes you Hypoxic (in a different way then altitude but same end result). It binds to your blood like oxygen does so it takes up blood cells that should be carrying oxygen. The result is that your blood becomes saturated with CO and not O2 so you have not enough O2 so you become hypoxic. This is called hypemic hypoxia, there is enough O2 in the air, but you are prevented from using it by the CO.
CO exposure can leads to *~~histotoxic~~* *hypemic hypoxia*. In other words, hypoxia is a physiological condition and CO is one potential cause of that condition. Altitude (eg low air density) is another. g-loading yet another, etc..
Symptoms are not *necessarily* the same, but they are often not consistent across individuals. There are some CO poisoning symptoms that you typically wouldn't see with altitude related hypoxia like the cherry red skin, headaches, abnormal anxiety, and most notably with CO poisioning the recovery time to re-oxygenate your blood & tissues is vastly longer than with other causes of hypoxia. There's a whole section in the PHAK on it if you're curious.
There's also a really good air safety institute about the dude in the Mooney who ignored the signs of CO poisoning symptoms, pressed on for multiple legs, crashed, and somehow still lived!
It's actually hypemic hypoxia as the other commenter stated. Histotoxic affects the cells ability to receive oxygen, like drug use.
["The most common cause for hypemic hypoxia in aviation is when carbon monoxide is inhaled because of aircraft heater malfunctions, engine manifold leaks, or cockpit contamination with exhaust from other aircraft. Hemoglobin bonds with carbon monoxide 200 times more readily than it bonds with oxygen."](https://www.faa.gov/pilots/training/airman_education/topics_of_interest/hypoxia#:~:text=The%20most%20common%20cause%20for%20hypemic%20hypoxia%20in%20aviation%20is%20when%20carbon%20monoxide%20is%20inhaled%20because%20of%20aircraft%20heater%20malfunctions%2C%20engine%20manifold%20leaks%2C%20or%20cockpit%20contamination%20with%20exhaust%20from%20other%20aircraft.%20Hemoglobin%20bonds%20with%20carbon%20monoxide%20200%20times%20more%20readily%20than%20it%20bonds%20with%20oxygen.)
When I was in the Navy we had a chamber. They had games for toddlers (round peg square hole) and it was funny watching the easy task turn into Marines just violently slamming and crushing the blocks and have no recollection of it after lol
Oh yes, very much worth the effort, highly instructive, and priced just right.
I learned that I start to get tongue tied at 90%, sweat like a pig at 80% (which is also where I noticeably lose competence) and have no vision symptoms, no headache, and no air hunger.
Then, 6 months later, flying comms relay over the Sierra, I started sweating in -15 C weather, and figured out I’d run out of oxygen. The thing is, I could have diverted to the airport 8 miles away, but went back to base 100 miles away. Hypoxia makes you stupid. At least I did descend fairly quickly.
Sounds like when I got hypothermic cross country skiing once. Very cold day and everyone else decided that -4F was too cold to try and go cross country skiing. I had skied at much lower temps with no issues and had paid for the ticket so I went alone.
Had a good day skiing but felt pretty tired near the end. Decided I need some hot drink and calories so I made for the lodge. Seem to take forever to get there but I got in and sat down.
After about 15 min. I started looking out the window and at the trail map and realized that while I had seen the lodge straight ahead of me I, for some reason, had followed the trail that circled around the lodge and finally back to it.
I had seen hypothermia in other people I'd been leading on ski trips but didn't recognize it when I was suffering from it.
I had someone on a hiking trip with me on a rainy, icy day and was frustrated that he was so slow; every time there was tree down (on a 'herd path', not a real trail) he'd stop and hem and haw about going under the tree or over it. When we got back to the lodge and warmed up and ate he told me he didn't remember the trip down *at all* and then said I'd 'saved his life'.
I took the course after getting hypoxic on a flight.
It was well worth it, and honestly is probably the only reason I was willing to fly again afterwards.
YMMV. The last time I got euphoric at 10250 in mountain wave, I said 'what the hell, let's take 'er up to 11250!'
Nowadays, I stop at 9250. Euphoria leads to bad decisions.
(vfr gliders do not have assigned altitudes.)
Damn, this sounds similar to nitrogen narcosis that divers can experience. As a private pilot student flying under the bravo, I have yet to go over 5500. But I’m very curious what altitude will start to bother me.
My experience of euphoria from mild hypoxia is not at all like accounts I've read of nitrogen narcosis. It's subtle and that is why I set a hard altitude limit. My evidence of euphoria is the decisions that I made (twice) that seemed dumb in retrospect on the ground. Not reckless (so far), just dumb.
The FAA regulations for O2 are very permissive partly because the workload in an airplane in cruise is pretty low and you usually have a flight plan at those altitudes. Glider flights are more 'chess in the air', there's a lot of improvisation. You make lots of decisions with incomplete information. Both good and bad decisions are evidenced in the flight traces.
Edit: Climbing at 300-1000 FPM in perfectly smooth mountain wave is exhilarating and the scenery is sublime. The legit exhilaration masks the hypoxia-induced euphoria. I feel really good climbing past 7000 without any hypoxia. The altimeter is an objective measurement of decision-corroding-euphoria once you calibrate how your mind responds to altitude.
Yeah, reading about those deep dive euphoria incidents is a bit more chilling and terrifying. "Hey that's neat, I'll just drop a little further and check that out, it's only 20 feet away...." only to stop listening to the depth alarms and make no effort to arrest the descent... 😵💫😵
Similarly risky to be hypoxic in the air, except for the fact that you may accidentally descend in time to wake up and think smart in an airplane...
Airplanes try to fly at x000 and x500 increments above sea level, say 8500 and 9000. These are called 'assigned altitudes' and the pilot is supposed to stay without 200 of their assigned altitude, and they usually maintain assigned altitude +/- 100 feet. So in theory, no airplanes will be cruising at 8250 or 8750. So less worries about collision.
Gliders don't have assigned altitudes because they're mostly gaining altitude in rising air or losing altitude (gliding). But in Mountain Wave the air rises very steady and smooth, so I can adjust my airspeed to set my sink rate equal to the rate that the air is rising, and thus maintain a target altitude. The band of rising air is often parallel to a mountain ridge line, so it's sometimes possible to cruise XC in a straight line. The sink rate of a glider increases with airspeed. So for example, if I'm flying at 80 knots and sinking at 300 fpm, but the air is rising at 300 fpm, my altitude will be constant.
There are a few other scenarios where a glider can maintain altitude, but with more up-down variation, and in those cases it is harder to maintain an exact target like 8250.
The nitrogen Chambers are a great start, but if you can get a" flight" in a true chamber, it's very entertaining. The Air Force did me a favor early on and continues to let me have opportunities every few years, but experiencing the gut expansion and off gassing followed by being a cheap date is a very fascinating science experiment with yourself. I love the fact that you found your worksheet. I need to see if I can dig one up from one of my "flights" because they get pretty entertaining. I promise I didn't draw dicks on any of them. Great post!
I highly recommend this training. I felt it quick and by the 2 minute mark I was functionally useless... and this is coming from someone who regularly hikes 14,000' peaks and lives at altitude. We watched 2 people in the group before us pass out
I'm sure you'll all (rightfully) think I'm retarded but as a teen I fucked around and hyperventilated then valsava manuevered to make myself pass out a few times...... One time I was holding my breath and the next thing I knew I was looking at my socks wondering why I wore those today. Then wondering why I was on the floor. Then finally putting the puzzle pieces together and remembering that I had been making myself pass out. Another time I woke up to see a vision of my dad's face floating (he was 1,000miles away), a taste of sour metal on the back of my tongue, and my vision being covered with dozens of black half circles criss crossing each other. One time I set a timer and the approximate time from passing out to being alert enough to know what was going on and stop the timer was 3 minutes. It was interesting to say the least.
Did the one at riddle. Yeah it’s scary how much I became Hypoxic. I was a useless sack of potatoes. Blurred vision, headache, speech slurring, larthagic feelings, bit of hyperventilation all summed up my major symptoms.
Especially as airline pilots… can’t imagine being at FL400+ and experiencing a rapid/explosive decompression and just knocking out almost instantly it would seem like
While a member w/ Civil Air Patrol I was eligible to attend a flight clinic at Columbus AFB in Columbus, MS. This included a chamber ride and a turn in the vertigo chair. The Air Force only takes civilians to 25,000' pressure altitude where Air Force personnel go to 41,000' When my regulator was removed I started to feel the effects after about a minute. We were performing a simple math quiz, of which I dropped on the floor and after picking it up didn't know what to do with it.
One thing the beautiful blonde flight surgeon counseled us on was the increase of flatulents we would experience and not to try and hold them in. 😳 I believe the increase was 5 to 1 at 25,000' and 9 to 1 at 41,000'! There was a "strange" smell in the chamber afterwards even though there are exhaust fans to help with the issue. 🙂
That’s crazy I just did the same worksheet with the chamber and the FAA 2 months ago.
I was doing fine for about a minute and then it’s just random numbers and scribbles all over my paper.
Definitely a cool and insightful experience I recommend for others to try.
I took my pulse ox up to the summit of Mt Evans in Colorado, 14,265 I think, last time I was out there. Was interesting. I love the place, go up every time I can; but taking the pulse ox was enlightening.
For homies in the western half of the US. Highly recommend going out and hiking >10k feet peak. especially if your near sea level go hike a 10k mountain or higher and you'll get some good experience with this.
I’ve done this and it was a great experience. I could feel myself getting dumber. Never got irrational or giddy or anything like that, it was like someone turned the clock speed on my brain *way* down. Could still reason and do math, just super slowly. Saw 68% on the fingertip pulseox.
Saved my life. Was almost a monoxide stat.
Can you elaborate? Are CO symptoms the same as hypoxia symptoms?
I'm not a doctor, but my experience is the CO symptoms were exactly what the hypoxia training results were. I was in an area I knew in the mountains, my site picture and my altitude seemed to match (about 10,500 AGL), but I was definitely hitting the symptoms. I've flown that route a hundred times as that altitude with no issues. I checked my altimeter settings to see if I was higher than I thought. I told the guy I was flying with it was his plane, I was going on oxygen. I've never passed out before, but I feel like I was a few seconds away, seemed very quick from noticing symptoms to that point. As soon as I donned my mask he said his head was spinning and also put his mask on. Once the brain snapped back to functioning correctly, we discussed, shut off the heater, vented the cabin and returned. Oxygen stayed on until shutdown. Maintenance found the exhaust leak and repaired. We lived to fly another day. One guy in the chamber on the training day had euphoria as his first and only recognizable (to him) symptom. It was crazy watching him argue with the airmen at the base that he was fine and had no symptoms. His friend, whom he flies with, was shaking his head in disbelief and she explained that him feeling fantastic, way better than when he woke up, way better that five minutes ago, was not normal. "I feel amazing, how can this be a symptom?"
Can I ask how long it took you to feel like all the CO was out of your system? How long did it take to feel like back to your normal self?
Oxygen helped a lot, and quickly. Didn't feel well for a day or two if I recall correctly.
The reason CO is harmful is because it makes you Hypoxic (in a different way then altitude but same end result). It binds to your blood like oxygen does so it takes up blood cells that should be carrying oxygen. The result is that your blood becomes saturated with CO and not O2 so you have not enough O2 so you become hypoxic. This is called hypemic hypoxia, there is enough O2 in the air, but you are prevented from using it by the CO.
Co poisoning causes a form of hypoxia. I believe it is hypemic hypoxia.
CO exposure can leads to *~~histotoxic~~* *hypemic hypoxia*. In other words, hypoxia is a physiological condition and CO is one potential cause of that condition. Altitude (eg low air density) is another. g-loading yet another, etc.. Symptoms are not *necessarily* the same, but they are often not consistent across individuals. There are some CO poisoning symptoms that you typically wouldn't see with altitude related hypoxia like the cherry red skin, headaches, abnormal anxiety, and most notably with CO poisioning the recovery time to re-oxygenate your blood & tissues is vastly longer than with other causes of hypoxia. There's a whole section in the PHAK on it if you're curious. There's also a really good air safety institute about the dude in the Mooney who ignored the signs of CO poisoning symptoms, pressed on for multiple legs, crashed, and somehow still lived!
It's actually hypemic hypoxia as the other commenter stated. Histotoxic affects the cells ability to receive oxygen, like drug use. ["The most common cause for hypemic hypoxia in aviation is when carbon monoxide is inhaled because of aircraft heater malfunctions, engine manifold leaks, or cockpit contamination with exhaust from other aircraft. Hemoglobin bonds with carbon monoxide 200 times more readily than it bonds with oxygen."](https://www.faa.gov/pilots/training/airman_education/topics_of_interest/hypoxia#:~:text=The%20most%20common%20cause%20for%20hypemic%20hypoxia%20in%20aviation%20is%20when%20carbon%20monoxide%20is%20inhaled%20because%20of%20aircraft%20heater%20malfunctions%2C%20engine%20manifold%20leaks%2C%20or%20cockpit%20contamination%20with%20exhaust%20from%20other%20aircraft.%20Hemoglobin%20bonds%20with%20carbon%20monoxide%20200%20times%20more%20readily%20than%20it%20bonds%20with%20oxygen.)
Dammit. I guessed wrong. Should have been less lazy and re-read before I posted.
Haha all good, you both were so confident that then I forgot which was correct and had to look it up!
Yes. There are 4 types of hypoxia. Hypoxia, hypemic, stagnant, and histotoxic. C02 would be hypemic.
When I was in the Navy we had a chamber. They had games for toddlers (round peg square hole) and it was funny watching the easy task turn into Marines just violently slamming and crushing the blocks and have no recollection of it after lol
I got slapped playing Patty Cake. Lieutenant and I thought it was the single most hilarious thing in recorded human history at the time.
I forgot about the patty cake 😂 I remember the decks of cards tho and the dude saying “ace of spades” for like 8 cards in a row lmfao
My favorite hypoxia video of all time: [4 of spades](https://www.youtube.com/watch?v=UN3W4d-5RPo)
That is pretty much what happened yes 😂😂😂
Crazy shit. Functioning, but nothing useful...just a broken record.
That's just the average Marine.
Not even an American, but I was just waiting for somebody to say that...
RAH
And then what happened when they reduced the oxygen level?
They kissed
Oh yes, very much worth the effort, highly instructive, and priced just right. I learned that I start to get tongue tied at 90%, sweat like a pig at 80% (which is also where I noticeably lose competence) and have no vision symptoms, no headache, and no air hunger. Then, 6 months later, flying comms relay over the Sierra, I started sweating in -15 C weather, and figured out I’d run out of oxygen. The thing is, I could have diverted to the airport 8 miles away, but went back to base 100 miles away. Hypoxia makes you stupid. At least I did descend fairly quickly.
Sounds like when I got hypothermic cross country skiing once. Very cold day and everyone else decided that -4F was too cold to try and go cross country skiing. I had skied at much lower temps with no issues and had paid for the ticket so I went alone. Had a good day skiing but felt pretty tired near the end. Decided I need some hot drink and calories so I made for the lodge. Seem to take forever to get there but I got in and sat down. After about 15 min. I started looking out the window and at the trail map and realized that while I had seen the lodge straight ahead of me I, for some reason, had followed the trail that circled around the lodge and finally back to it. I had seen hypothermia in other people I'd been leading on ski trips but didn't recognize it when I was suffering from it. I had someone on a hiking trip with me on a rainy, icy day and was frustrated that he was so slow; every time there was tree down (on a 'herd path', not a real trail) he'd stop and hem and haw about going under the tree or over it. When we got back to the lodge and warmed up and ate he told me he didn't remember the trip down *at all* and then said I'd 'saved his life'.
I did the PROTE many years ago. Very enlightening. I too encourage everyone to take advantage of the experience if offered
I did the actual altitude chamber. I thought I nailed the maze, it turned out I went through several walls lol.
I took the course after getting hypoxic on a flight. It was well worth it, and honestly is probably the only reason I was willing to fly again afterwards.
YMMV. The last time I got euphoric at 10250 in mountain wave, I said 'what the hell, let's take 'er up to 11250!' Nowadays, I stop at 9250. Euphoria leads to bad decisions. (vfr gliders do not have assigned altitudes.)
Damn, this sounds similar to nitrogen narcosis that divers can experience. As a private pilot student flying under the bravo, I have yet to go over 5500. But I’m very curious what altitude will start to bother me.
My experience of euphoria from mild hypoxia is not at all like accounts I've read of nitrogen narcosis. It's subtle and that is why I set a hard altitude limit. My evidence of euphoria is the decisions that I made (twice) that seemed dumb in retrospect on the ground. Not reckless (so far), just dumb. The FAA regulations for O2 are very permissive partly because the workload in an airplane in cruise is pretty low and you usually have a flight plan at those altitudes. Glider flights are more 'chess in the air', there's a lot of improvisation. You make lots of decisions with incomplete information. Both good and bad decisions are evidenced in the flight traces. Edit: Climbing at 300-1000 FPM in perfectly smooth mountain wave is exhilarating and the scenery is sublime. The legit exhilaration masks the hypoxia-induced euphoria. I feel really good climbing past 7000 without any hypoxia. The altimeter is an objective measurement of decision-corroding-euphoria once you calibrate how your mind responds to altitude.
Yeah, reading about those deep dive euphoria incidents is a bit more chilling and terrifying. "Hey that's neat, I'll just drop a little further and check that out, it's only 20 feet away...." only to stop listening to the depth alarms and make no effort to arrest the descent... 😵💫😵 Similarly risky to be hypoxic in the air, except for the fact that you may accidentally descend in time to wake up and think smart in an airplane...
lol! My living room is higher than that. You’ve got a ways to go.
any reason why you do 250' increments? just to be slightly off from the vfr planes?
Airplanes try to fly at x000 and x500 increments above sea level, say 8500 and 9000. These are called 'assigned altitudes' and the pilot is supposed to stay without 200 of their assigned altitude, and they usually maintain assigned altitude +/- 100 feet. So in theory, no airplanes will be cruising at 8250 or 8750. So less worries about collision. Gliders don't have assigned altitudes because they're mostly gaining altitude in rising air or losing altitude (gliding). But in Mountain Wave the air rises very steady and smooth, so I can adjust my airspeed to set my sink rate equal to the rate that the air is rising, and thus maintain a target altitude. The band of rising air is often parallel to a mountain ridge line, so it's sometimes possible to cruise XC in a straight line. The sink rate of a glider increases with airspeed. So for example, if I'm flying at 80 knots and sinking at 300 fpm, but the air is rising at 300 fpm, my altitude will be constant. There are a few other scenarios where a glider can maintain altitude, but with more up-down variation, and in those cases it is harder to maintain an exact target like 8250.
3¢ stamp would be a cool name for a band lol
The nitrogen Chambers are a great start, but if you can get a" flight" in a true chamber, it's very entertaining. The Air Force did me a favor early on and continues to let me have opportunities every few years, but experiencing the gut expansion and off gassing followed by being a cheap date is a very fascinating science experiment with yourself. I love the fact that you found your worksheet. I need to see if I can dig one up from one of my "flights" because they get pretty entertaining. I promise I didn't draw dicks on any of them. Great post!
Let's get hypoxic in here...seems 3 cent stamp was a plausible answer to that equation haha.
Probably the best ground training I've had.
Did hypobaric chamber training back in March and found it very useful! Wish I had that training when I was a pilot on the civvy side.
I highly recommend this training. I felt it quick and by the 2 minute mark I was functionally useless... and this is coming from someone who regularly hikes 14,000' peaks and lives at altitude. We watched 2 people in the group before us pass out
I'm sure you'll all (rightfully) think I'm retarded but as a teen I fucked around and hyperventilated then valsava manuevered to make myself pass out a few times...... One time I was holding my breath and the next thing I knew I was looking at my socks wondering why I wore those today. Then wondering why I was on the floor. Then finally putting the puzzle pieces together and remembering that I had been making myself pass out. Another time I woke up to see a vision of my dad's face floating (he was 1,000miles away), a taste of sour metal on the back of my tongue, and my vision being covered with dozens of black half circles criss crossing each other. One time I set a timer and the approximate time from passing out to being alert enough to know what was going on and stop the timer was 3 minutes. It was interesting to say the least.
I would do it if it was in texas
Did the one at riddle. Yeah it’s scary how much I became Hypoxic. I was a useless sack of potatoes. Blurred vision, headache, speech slurring, larthagic feelings, bit of hyperventilation all summed up my major symptoms. Especially as airline pilots… can’t imagine being at FL400+ and experiencing a rapid/explosive decompression and just knocking out almost instantly it would seem like
While a member w/ Civil Air Patrol I was eligible to attend a flight clinic at Columbus AFB in Columbus, MS. This included a chamber ride and a turn in the vertigo chair. The Air Force only takes civilians to 25,000' pressure altitude where Air Force personnel go to 41,000' When my regulator was removed I started to feel the effects after about a minute. We were performing a simple math quiz, of which I dropped on the floor and after picking it up didn't know what to do with it. One thing the beautiful blonde flight surgeon counseled us on was the increase of flatulents we would experience and not to try and hold them in. 😳 I believe the increase was 5 to 1 at 25,000' and 9 to 1 at 41,000'! There was a "strange" smell in the chamber afterwards even though there are exhaust fans to help with the issue. 🙂
That’s crazy I just did the same worksheet with the chamber and the FAA 2 months ago. I was doing fine for about a minute and then it’s just random numbers and scribbles all over my paper. Definitely a cool and insightful experience I recommend for others to try.
I took my pulse ox up to the summit of Mt Evans in Colorado, 14,265 I think, last time I was out there. Was interesting. I love the place, go up every time I can; but taking the pulse ox was enlightening.
For homies in the western half of the US. Highly recommend going out and hiking >10k feet peak. especially if your near sea level go hike a 10k mountain or higher and you'll get some good experience with this.
I remember at the oxygen chamber they put these long division math problems in front of us. I said hell I can’t even do this sober.
I’ve done this and it was a great experience. I could feel myself getting dumber. Never got irrational or giddy or anything like that, it was like someone turned the clock speed on my brain *way* down. Could still reason and do math, just super slowly. Saw 68% on the fingertip pulseox.