Roost Air Lounge => The Classroom => Topic started by: Callisto on August 10, 2006, 01:36:14 PM
Title: Higher Altitudes and O2
Post by: Callisto on August 10, 2006, 01:36:14 PM
At what altitude is oxygen required? I'm talking non commercial, C-182 or Bonanza type non-pressurized GA. What is the FAR and what do you guys/gals do about using O2 and having your passengers use O2?
Title: Re: Higher Altitudes and O2
Post by: Callisto on August 10, 2006, 01:37:40 PM
I know, I know oxygen is required at ALL altitudes... But when do you need to add it... you know what I meant! ;D ;D ;D
Title: Re: Higher Altitudes and O2
Post by: C310RCaptian on August 10, 2006, 03:11:28 PM
Someone correct me if I am wrong…but think it goes like this…………
Up to 12,500 feet oxygen is not required by FARS. Between 12,501 to 14,000 oxygen is required only if you are there for more than 30 minutes. Less than that, you don’t need it. From 14,001 to 15,000 the crew only needs oxygen continuously. I love that part. I have a drunk and obnoxious pax ill climb up as high as I can…. 15,000 on special occasion…. And let them pass out ::) ….. Works wonders. And finally above 15,000 everyone needs oxygen…Hope that helps you out. Where you planning on going and how high? ;D
Title: Re: Higher Altitudes and O2
Post by: Callisto on August 10, 2006, 03:38:03 PM
Back story: A few co-workers flew to Nebraska for a meeting with a client in the prez Bonanza. On the way back they were cruising at 11,000 and one guy checked his O2 Saturation (I guess there was an O2 Sat machine on board...) Anyway his reading was 86%. He asked his wife (an nurse) and she said they put people on oxygen if their sat rate is below 92% or something (I may be off on my numbers... but bottom line was the O2 reading was lower than the minimum the hospital puts people on O2 (if that makes sense))
So he's freaking out about brain damage and hypoxia... out of curiosity I was wondering where the danger point was.
I like the idea of knocking out obnoxious passengers! ;D
Title: Re: Higher Altitudes and O2
Post by: fireflyr on August 10, 2006, 04:42:45 PM
FAR 91.211 says exactly what C310 captain quoted but the effects of hypoxia are insidious, especially at night when it is suggested you should use O2 anytime you are above 10 grand because of the effects on night vision. I learned exactly how insidious it is one afternoon when another pilot and I spent about an hour at 17,000 without supplemental O2, when SAC approach cleared us direct SAC VOR neither could figure out how to do that---they finally suggested a heading----how embarrassing is that! :-[
Title: Re: Higher Altitudes and O2
Post by: C310RCaptian on August 10, 2006, 06:05:41 PM
I like hypoxia!!! Makes me feel great (and that’s the dangerous part about it)….. One of the best things any pilot can do is to go to a hypobaric chamber or altitude chamber… they will simulate what it is like at 25,000 feet without oxygen!!!!!! I did it last winter and man was it awesome… I learned that at 25K I have 2 min of useful conciseness…. After that forget about it... and I did. I don’t remember a thing past the 2 min mark. I don’t even remember putting on my own oxygen mask. When I did 2 deep breaths and I was snapped back like nothing ever happened. Another plus is you get to see your friends do it. The instructors will give them a baby toy and tell them to do it, like put the circle shapes through the correct hole, and they will try there hardest to shove it through the wrong hole. Its so much fun.
The REAL reason you want to do it is so you can see your symptoms of hypoxia and correct it before you come to euphoric. My biggest symptom was that I get jittery. Knees start to shake nervously and my fingers turn really, really blue. Great tool if you fly high in any aircraft.
The one I attended was in Oklahoma city, OK with the feds…somehow I got away clean…. but I know there are about 10 different, pilot certificate friendly, ones around the country.
Title: Re: Higher Altitudes and O2
Post by: happylanding on August 10, 2006, 08:25:21 PM
Am I wrong if I say that - that is what I seem to remember - Hypoxia is connected also to people's habit? I mean, if you smoke it comes fast, if you have an healthy life it takes its time?!?
Title: Re: Higher Altitudes and O2
Post by: fireflyr on August 10, 2006, 08:58:04 PM
Am I wrong if I say that - that is what I seem to remember - Hypoxia is connected also to people's habit? I mean, if you smoke it comes fast, if you have an healthy life it takes its time?!?
Somewhat the contrary, smokers have a higher hemoglobin content in the blood and (depending on health, of course) can withstand altitudes very well. Just like people who live at higher altitudes have higher hemoglobin counts. Go figure!!!! :-\
Title: Re: Higher Altitudes and O2
Post by: happylanding on August 10, 2006, 09:30:30 PM
Oh my! I should have better kept silent! :) I clearly demonstrated that in aeronautical medicine I was a complete zero! When I did my PPL license theory exam, I failed either medicine or law (figure out why I don't wanna be a lawyer!!) :) :)
Title: Re: Higher Altitudes and O2
Post by: fireflyr on August 11, 2006, 08:54:59 AM
Oh my! I should have better kept silent! :) I clearly demonstrated that in aeronautical medicine I was a complete zero! When I did my PPL license theory exam, I failed either medicine or law (figure out why I don't wanna be a lawyer!!) :) :)
No worry Happy----the only reason I know that is because I'm a smoker :P and my flight doctor pointed it out to me.
Title: Re: Higher Altitudes and O2
Post by: Callisto on August 11, 2006, 01:59:00 PM
Ok so this might be a stupid question... What about people who live above 10,000 ft? Do they just adapt? Does hypoxia occur faster in people who live closer to sea level? Would I, living near Chicago (500-600ft above sea level) be more at risk of passing out due to hypoxia than someone from let's say Colorado (10,000+ft)?
Sorry if I sound like a newbie... my only flight experience is in a pressurized aluminium tube at 30,000ft+... or sitting at my computer with MSFS! :-[
Title: Re: Higher Altitudes and O2
Post by: C310RCaptian on August 11, 2006, 03:37:46 PM
Well that’s a good question. I think they found that those living at higher altitudes tend to use more of there lungs than those living at lower altitudes. Down low our body doesn’t have to work very hard to get the required amount of oxygen so we don’t use al of our lungs potential. My guess is that we only use 60 to 70 percent of our lungs while those at higher altitude or those that are very physically fit use closer to 90 percent of there lungs. Does living down low make you more susceptible to hypoxia… probably but not in a noticeable way.
Also lets not forget that you can get hypoxia at any altitude. There is more than one type. I can try and find better definitions for them if anyone is interested.
Title: Re: Higher Altitudes and O2
Post by: fireflyr on August 11, 2006, 08:52:13 PM
Lung capacity is a factor but the increase in hemaglobin happens as your body gets used to thinner air.
Title: Re: Higher Altitudes and O2
Post by: Callisto on August 11, 2006, 09:17:35 PM
Interesting... This peaked my interest so I did a few Google searches (where would we be with out Google :))
http://anthro.palomar.edu/adapt/adapt_3.htm
About acclimating and how people can live 3+ miles up. Hemoglobin is higher in people who live higher. So fireflyr is 100% right, not that I was doubting... but just validating your facts ;D
Bottom line though... an hour at 11,000 isn't gonna brain your damage. But above 12,500 use it.
Title: Re: Higher Altitudes and O2
Post by: Ted_Stryker on August 21, 2006, 08:54:31 PM
My parents used to live up on a mountaintop in Boulder, Colorado. The elevation where they were at was close to 9,500 ft MSL. It would take a few days at least for me to adjust going out there as I live in St. Louis, Missouri, in an area only about 450 to 500 ft MSL on average. After you get used to it, which to fully do can take considerably longer than a few days, it's easily tollerated.
I would be wary of flying without O2 up there even if under 12,500 though for any length of time. It certainlay can't hurt to have supplemental oxygen on when at an altitude significantly higher than what one is used to normally.
I've also been in an unpressurized aircraft as a passenger at 13,000 feet MSL on one occassion. It was not a pleasant experience! You know how the FAA rules read that the pilot has to have oxygen, but no real requirement for the passengers is there if you're below 14,000? Granted, the FAA wants to make sure the pilot can fly the plane properly.... but they obviously don't care if your passengers are literally blue in the face :o ::) ;D
I guess the old saying is true about the FAA...."We're not happy until you're not happy!" ;D
Title: Re: Higher Altitudes and O2
Post by: Plthijnx on August 24, 2006, 05:39:19 AM
just food for thought, i am a smoker and have smoked in the cockpit at FL 125 with no problems at all. however i did enjoy the hallooosinashuns! (j/k) really though, i haven't had a problem at all. no signs of hypoxia. i guess it's like fireflyr said "Somewhat the contrary, smokers have a higher hemoglobin content in the blood and (depending on health, of course) can withstand altitudes very well. Just like people who live at higher altitudes have higher hemoglobin counts. Go figure!!"
Title: Re: Higher Altitudes and O2
Post by: happylanding on August 24, 2006, 07:34:51 PM
I just smoked once on a plane, and I remember that I felt like it were the first cigarette after a halt of 24 hours; or my first cigarette at all: you know, when it kicks, when you feel dizzy for some seconds and feel tickle in the fingers...not a nice feeling since I was sure I was going to puke, even if I'm completely addicted. :P :(
Title: Re: Higher Altitudes and O2
Post by: tundra_flier on September 06, 2006, 11:44:50 PM
I wonder is there are any long term effects of living at high altitudes? I grew up in Wyoming at 5,000ft, but have been living at 400ft for the last 16 years. About 4 years back I was going out to a bush village on a charter flight. Since I'm a pilot, the captain let me take the right seat in the Navajo. We ended up spending about 2 hours at 12,000ft between layers. I didn't recognize any hypoxia effects in myself, and of course the pilot was fine. But the other 5 passengers were all complaining about fatige, headaches, dizzyness etc, and a couple of them are in far better shape than I am. And since we were between layers, there was no way the other passengers could know how high we were. Could there be some residual effects of growing up at high altitude?
I don't nomally fly above 3,000 ft myself. I think tundra toy would run out of fuel before I got her up to 12,000. ;)
Phil
Title: Re: Higher Altitudes and O2
Post by: Ted_Stryker on September 07, 2006, 02:22:14 AM
I wonder is there are any long term effects of living at high altitudes? I grew up in Wyoming at 5,000ft, but have been living at 400ft for the last 16 years. About 4 years back I was going out to a bush village on a charter flight. Since I'm a pilot, the captain let me take the right seat in the Navajo. We ended up spending about 2 hours at 12,000ft between layers. I didn't recognize any hypoxia effects in myself, and of course the pilot was fine. But the other 5 passengers were all complaining about fatige, headaches, dizzyness etc, and a couple of them are in far better shape than I am. And since we were between layers, there was no way the other passengers could know how high we were. Could there be some residual effects of growing up at high altitude?
I don't nomally fly above 3,000 ft myself. I think tundra toy would run out of fuel before I got her up to 12,000. ;)
Phil
Those that grow up in a thinner atmosphere do tend to have better capacity to oxygenate due to higher hemoglobin counts. I don't know if there are any studies relating to if this is persistent, but anecdotally, I've seen those that grow up in places like Denver, or Boulder, Colorado (about the same elevation as where you grew up), tend to keep and have a higher tollerance for altitude changes and adapt more quickly. It would be a good study to run. I also know that the military trains the elite "black ops" groups in high altitude conditions for months before deployment to places like Afghanistan to help them acclimate easily. Again, anecdotally, I think there may be something to the development of tendancies for efficiencies if growing up in such environments.
Title: Re: Higher Altitudes and O2
Post by: Baradium on September 07, 2006, 05:40:35 AM
Oxygen rules vary by operation.
We are required to provide oxygen on a percentage basis. IE, we have to have oxygen availible to x% of passengers above 12,500 for more than 30 minutes to 14,000 and x% to 15,000 and 100% above that. That's for part 121 carriers...
The smoking thing is misleading, smokers are known to have worse night vision. Smoking a cigarette before you go flying will also take care of any advantage for hypoxia (because your body is used to little oxygen when you are smoking) and then some.
BTW, you technically can't have a FL125 (sorry). Flight levels are defined by regulation and don't start until 18,000 and even then a flight lever isn't 18,000 MSL it's 18,000 with altimeter to 29.92. ;)
I thought it was so cool the first time I set the altimeter to 29.92 and got to talk about flight levels with ATC. ;)
Title: Re: Higher Altitudes and O2
Post by: Ted_Stryker on September 07, 2006, 06:43:13 AM
We are required to provide oxygen on a percentage basis. IE, we have to have oxygen availible to x% of passengers above 12,500 for more than 30 minutes to 14,000 and x% to 15,000 and 100% above that. That's for part 121 carriers...
The smoking thing is misleading, smokers are known to have worse night vision. Smoking a cigarette before you go flying will also take care of any advantage for hypoxia (because your body is used to little oxygen when you are smoking) and then some.
BTW, you technically can't have a FL125 (sorry). Flight levels are defined by regulation and don't start until 18,000 and even then a flight lever isn't 18,000 MSL it's 18,000 with altimeter to 29.92. ;)
I thought it was so cool the first time I set the altimeter to 29.92 and got to talk about flight levels with ATC. ;)
The oxygen rule for us regular folks is that you have to have O2 on if at or above 12,500 for more than 30 minutes, 14,000 and up you have to be on it full time, and only after 15,000 do you have to provide it for your passengers.
I know the FAA wants pilots to be safe and alert.... but it seems to me that if you are in an unpressurized environment, and have passengers without O2 at 14,000 feet for any length of time, you're running a risk of them not doing too well. I guess the FAA does care more about us pilots than the passengers ;D
Title: Re: Higher Altitudes and O2
Post by: happylanding on September 07, 2006, 06:51:13 AM
Wait to be a fighter pilot (but there you shouldn't have any more pax, right?!?) and you gain the last needed strip to godness! :D :D
Very true!!! Unless you have your RIO or ECMO along for the ride in a two seater :) (RIO = Radar Intercept Officer and ECMO = Electronic CounterMeasures Officer) Then again... you don't want those guys getting loopy on you! :)
Title: Re: Higher Altitudes and O2
Post by: fireflyr on September 07, 2006, 10:19:42 AM
Wait to be a fighter pilot (but there you shouldn't have any more pax, right?!?) and you gain the last needed strip to godness! :D :D
Very true!!! Unless you have your RIO or ECMO along for the ride in a two seater :) (RIO = Radar Intercept Officer and ECMO = Electronic CounterMeasures Officer) Then again... you don't want those guys getting loopy on you! :)
OH----You mean TGIB (the guy in back) 8)
Title: Re: Higher Altitudes and O2
Post by: tundra_flier on September 07, 2006, 03:15:38 PM
In the book "Glacier Pilot" it notes that Reeve Alutian Air was have a problem with drunk miners on it's DC-3's. So official policy was to climb till they passed out. If that didn't work, go zero G a couple times to bounce them off the ceiling. ;D I guess that pretty well setltled down even the roudiest pax.
Phil
Title: Re: Higher Altitudes and O2
Post by: Ted_Stryker on September 07, 2006, 04:21:08 PM
In the book "Glacier Pilot" it notes that Reeve Alutian Air was have a problem with drunk miners on it's DC-3's. So official policy was to climb till they passed out. If that didn't work, go zero G a couple times to bounce them off the ceiling. ;D I guess that pretty well setltled down even the roudiest pax.
Phil
Hehe! Great idea! I'm sure that today it would get one sued in court though... darn letigious nature of things today! :) >:( ;)
Title: Re: Higher Altitudes and O2
Post by: Gulfstream Driver on September 07, 2006, 05:33:27 PM
Great discussion, guys.
One note about flying at 12,500...There's nothing in the regs that say you can't fly above this altitude for 30 min, then sink below, then climb back up with a new 30 min clock. Not safe, but not illegal, either.
If anyone was curious about the types, they are hypoxic, histotoxic, hypemic, and stagnant. Hypoxic is due to altitude; histotoxic is caused by toxins interfering with the cells' ability to use oxygen (alcohol, drugs, etc); hypemic is due to smoking (CO bonds with hemoglobin better than oxygen); and stagnant is from blood pooling like when your arm falls asleep.
Title: Re: Higher Altitudes and O2
Post by: YawningMan on September 26, 2006, 09:50:15 PM
I've read that staying below 10,000 ft is ideal without pressurisation. I've also read an article by a female pilot who was flying over 8,000 who became disoriented. Once she dipped below 8,000, things were back to normal. I think it can depend on the person.
This makes me curious, though. I wonder if a pressurized air machine would work differently than actual oxygen. Of course, there's the military, who use pressurized oxygen in their masks. They have the best of both.
My mother has been a respiratory therapist for as long as I know, so her speculations would probably put my guesses to shame. It still makes me wonder if pressurized ambient air without accompanying oxygen has been tried in flight, versus accompanying oxygen without pressurization.
I've been working in the medical field for 2 years, so I know enough to really do some damage. ;D
Title: Re: Higher Altitudes and O2
Post by: tundra_flier on September 26, 2006, 10:02:01 PM
Quote
It still makes me wonder if pressurized ambient air without accompanying oxygen has been tried in flight, versus accompanying oxygen without pressurization.
You mean pressurized cockpit vs oxygen mask? I was under the impression that a pressurized cockpit was the same as staying at a lower altitude physilogically. Or did I missinterpret your question?
Phil
Title: Re: Higher Altitudes and O2
Post by: Ted_Stryker on September 26, 2006, 10:06:16 PM
It still makes me wonder if pressurized ambient air without accompanying oxygen has been tried in flight, versus accompanying oxygen without pressurization.
You mean pressurized cockpit vs oxygen mask? I was under the impression that a pressurized cockpit was the same as staying at a lower altitude physilogically. Or did I missinterpret your question?
Phil
A pressurized cockpit/cabin does eliminate the need for supplemental oxygen in that it is the same to the body physiologically. The regs still state that pressurized or not, if you're over 14,000 you need to have it available. On commercial aircraft it is not unusual to have at least one crewmember on O2, especially if one of the other crew leaves the cockpit. This is a contingency procedure in case of a loss of pressurization, sudden or otherwise.
Title: Re: Higher Altitudes and O2
Post by: Baradium on September 27, 2006, 01:00:18 AM
I've read that staying below 10,000 ft is ideal without pressurisation. I've also read an article by a female pilot who was flying over 8,000 who became disoriented. Once she dipped below 8,000, things were back to normal. I think it can depend on the person.
This makes me curious, though. I wonder if a pressurized air machine would work differently than actual oxygen. Of course, there's the military, who use pressurized oxygen in their masks. They have the best of both.
My mother has been a respiratory therapist for as long as I know, so her speculations would probably put my guesses to shame. It still makes me wonder if pressurized ambient air without accompanying oxygen has been tried in flight, versus accompanying oxygen without pressurization.
I've been working in the medical field for 2 years, so I know enough to really do some damage. ;D
When you fly in an airliner, it's pressurized ambient air in the cabin.
-Ryan
Title: Re: Higher Altitudes and O2
Post by: Baradium on September 27, 2006, 01:03:49 AM
A pressurized cockpit/cabin does eliminate the need for supplemental oxygen in that it is the same to the body physiologically. The regs still state that pressurized or not, if you're over 14,000 you need to have it available. On commercial aircraft it is not unusual to have at least one crewmember on O2, especially if one of the other crew leaves the cockpit. This is a contingency procedure in case of a loss of pressurization, sudden or otherwise.
This might have been misleading... oxygen availible is determined by cabin pressure altitudes. Emergency oxygen systems under a different category are determined by the amount of time to get to an altitude that doesn't require oxygen IIRC.
For example, we have to offer oxygen to passengers if our cabin pressure is above xxx altitude, but we don't if we are above that altitude and our cabin pressure altitude stays low.
By availible I take it to mean the FAA definition that a passenger can use it if they want, not that it has to be around for the crew to deploy (such as our emergency oxygen systems).
Title: Re: Higher Altitudes and O2
Post by: Ted_Stryker on September 27, 2006, 02:16:47 PM
A pressurized cockpit/cabin does eliminate the need for supplemental oxygen in that it is the same to the body physiologically. The regs still state that pressurized or not, if you're over 14,000 you need to have it available. On commercial aircraft it is not unusual to have at least one crewmember on O2, especially if one of the other crew leaves the cockpit. This is a contingency procedure in case of a loss of pressurization, sudden or otherwise.
This might have been misleading... oxygen availible is determined by cabin pressure altitudes. Emergency oxygen systems under a different category are determined by the amount of time to get to an altitude that doesn't require oxygen IIRC.
For example, we have to offer oxygen to passengers if our cabin pressure is above xxx altitude, but we don't if we are above that altitude and our cabin pressure altitude stays low.
By availible I take it to mean the FAA definition that a passenger can use it if they want, not that it has to be around for the crew to deploy (such as our emergency oxygen systems).
Well said.... and correct. Thanks for clarifying. I did indeed, unintentionally, mix the requirements for emergency crew oxygen vice passenger O2 in my post. Sorry about any confusion my statement may have caused. :) That's what I get for posting before having had sufficient coffee ;D
Title: Re: Higher Altitudes and O2
Post by: fireflyr on September 27, 2006, 03:15:41 PM
A pressurized cockpit/cabin does eliminate the need for supplemental oxygen in that it is the same to the body physiologically. The regs still state that pressurized or not, if you're over 14,000 you need to have it available. On commercial aircraft it is not unusual to have at least one crewmember on O2, especially if one of the other crew leaves the cockpit. This is a contingency procedure in case of a loss of pressurization, sudden or otherwise.
This might have been misleading... oxygen availible is determined by cabin pressure altitudes. Emergency oxygen systems under a different category are determined by the amount of time to get to an altitude that doesn't require oxygen IIRC.
For example, we have to offer oxygen to passengers if our cabin pressure is above xxx altitude, but we don't if we are above that altitude and our cabin pressure altitude stays low.
By availible I take it to mean the FAA definition that a passenger can use it if they want, not that it has to be around for the crew to deploy (such as our emergency oxygen systems).
Well said.... and correct. Thanks for clarifying. I did indeed, unintentionally, mix the requirements for emergency crew oxygen vice passenger O2 in my post. Sorry about any confusion my statement may have caused. :) That's what I get for posting before having had sufficient coffee ;D
Don't you have an IV stand for caffiene next to your desk???
Title: Re: Higher Altitudes and O2
Post by: Baradium on September 27, 2006, 03:24:37 PM
Well said.... and correct. Thanks for clarifying. I did indeed, unintentionally, mix the requirements for emergency crew oxygen vice passenger O2 in my post. Sorry about any confusion my statement may have caused. :) That's what I get for posting before having had sufficient coffee ;D
I figured it was unintentional. I could tell what you meant, but wasn't sure if it was obvious for those who don't deal with oxygen requirements on a regular basis. ;)
I havn't had any coffee today, but I try to just not take caffiene period. I'm actually supposed to be at the airport, but as I was walking out the door company called and said to relax because there isn't an airplane for me. At least they're being nice and not paying me for sitting at home instead of not paying me for sitting at the airport all day. :-\
Title: Re: Higher Altitudes and O2
Post by: Ted_Stryker on September 27, 2006, 03:27:59 PM
A pressurized cockpit/cabin does eliminate the need for supplemental oxygen in that it is the same to the body physiologically. The regs still state that pressurized or not, if you're over 14,000 you need to have it available. On commercial aircraft it is not unusual to have at least one crewmember on O2, especially if one of the other crew leaves the cockpit. This is a contingency procedure in case of a loss of pressurization, sudden or otherwise.
This might have been misleading... oxygen availible is determined by cabin pressure altitudes. Emergency oxygen systems under a different category are determined by the amount of time to get to an altitude that doesn't require oxygen IIRC.
For example, we have to offer oxygen to passengers if our cabin pressure is above xxx altitude, but we don't if we are above that altitude and our cabin pressure altitude stays low.
By availible I take it to mean the FAA definition that a passenger can use it if they want, not that it has to be around for the crew to deploy (such as our emergency oxygen systems).
Well said.... and correct. Thanks for clarifying. I did indeed, unintentionally, mix the requirements for emergency crew oxygen vice passenger O2 in my post. Sorry about any confusion my statement may have caused. :) That's what I get for posting before having had sufficient coffee ;D
Don't you have an IV stand for caffiene next to your desk???
Hmm... IV stand at the desk..... GREAT IDEA!!! I'll have to work on that ;D ;D ;D Yesterday I went through almost two full pots of coffee before I went home and had another. Am I addicted to coffee? Nah... I can live without it. I can go days without a sip... but if it's available... :) :) :) I think it's more like that great quote from Ensign Pavel Chekov in the Star Trek episode "The Deadly Years". At one point Chekov is complaining about all the medical samples McCoy is taking and Sulu says "You'll live." Checkov's prompt retort is; "Oh yes, I'll live. But I won't enjoy it!" ;D ;D ;D
Title: Re: Higher Altitudes and O2
Post by: Ted_Stryker on September 27, 2006, 03:31:34 PM
Well said.... and correct. Thanks for clarifying. I did indeed, unintentionally, mix the requirements for emergency crew oxygen vice passenger O2 in my post. Sorry about any confusion my statement may have caused. :) That's what I get for posting before having had sufficient coffee ;D
I figured it was unintentional. I could tell what you meant, but wasn't sure if it was obvious for those who don't deal with oxygen requirements on a regular basis. ;)
I havn't had any coffee today, but I try to just not take caffiene period. I'm actually supposed to be at the airport, but as I was walking out the door company called and said to relax because there isn't an airplane for me. At least they're being nice and not paying me for sitting at home instead of not paying me for sitting at the airport all day. :-\
Well, glad they called you in enough time! I may be able to pop on the chat interface sometime in the next couple of hours. We could echange notes about flying experiences :)
Title: Re: Higher Altitudes and O2
Post by: Baradium on September 27, 2006, 03:39:35 PM
Well, glad they called you in enough time! I may be able to pop on the chat interface sometime in the next couple of hours. We could echange notes about flying experiences :)
Sounds good, I'll be in chat as long as they don't call me in.
Title: Re: Higher Altitudes and O2
Post by: tundra_flier on September 27, 2006, 05:04:18 PM
Quote
At least they're being nice and not paying me for sitting at home instead of not paying me for sitting at the airport all day.
Hmmmm...the airport is my favorite place to waste time. ;)
Phil
Title: Re: Higher Altitudes and O2
Post by: YawningMan on September 27, 2006, 06:43:24 PM
Oh, hehe. Yes, pressurized cabins are definitely pressurized ambient air, but that's not what I had meant.
My curiosity was for aircraft that can make it to those altitudes that might not have a pressurized cabin. Let me try again.
I work as a sleep lab technician. Most of the time, I am treating Sleep Apnea. For patients who have sleep apnea, they are prescribed a mask that fits over the nose, or the nose and the mouth. This creates pressurized ambient air in the nasal passages, or nasal and oral passages locally on the person. The rest of the body doesn't experience any kind of pressurized air.
What I was thinking is how useful it would be to develop a similar system as a way to provide an air supply to a pilot in flight who might not have a pressurized cabin, and might not have an easy time of finding a supplier of compressed O2, or would rather pay a higher cost upfront than have to always pay for the service to recharge his O2 tank.
As I think about it more and more, I'm beginning to doubt it's viability as a replacement for O2 for pilots. O2 can be delivered via a simple cannula. The pressurized air is delivered via a mask, or at best, by bigger tubing that fits in the nasal passages, called "Nasal pillows". While you wouldn't have to recharge your O2 canister, you would likely have to recharge a battery. This battery would likely have to be somewhat bulky to carry sufficient charge over a sustainable amount of time. Weight would likely be at least as much as an O2 canister, if not heavier.
Getting back to the mask, this could be problematic. I know pilots without perfect vision who opt out of wearing glasses because of limited visibility where the frames of the glasses lie in their field of view. The mask does sit somewhat in front of the eyes. Nasal Pillows don't, but I'm about to touch on the disadvantage with those.
Nasal masks or pillows might create a problem with communications. The pilot's microphone normally sits immediately in front of their lips. Everytime I've seen a pilot with a headset, that's where the microphone has been. With pressurized air in the nasal passageway, that means there will be a gust of air each time the pilot opens his mouth to speak into the microphone, and it could create unwanted interference, unless there was a dampener on the microphone. Still, if someone isn't used to the mask, it is unusual to try and speak with air rushing out of one's mouth.
Further considerations are the effects of the pressure on a person's ears. This is especially important in flight, and at higher altitudes. It could cause more problems than it fixes.
I guess I answered my own question. :)
Title: Re: Higher Altitudes and O2
Post by: Baradium on September 27, 2006, 07:09:55 PM
As I think about it more and more, I'm beginning to doubt it's viability as a replacement for O2 for pilots. O2 can be delivered via a simple cannula. The pressurized air is delivered via a mask, or at best, by bigger tubing that fits in the nasal passages, called "Nasal pillows". While you wouldn't have to recharge your O2 canister, you would likely have to recharge a battery. This battery would likely have to be somewhat bulky to carry sufficient charge over a sustainable amount of time. Weight would likely be at least as much as an O2 canister, if not heavier.
For it to work you'd have to be able to maintain the higher pressure of air in the lungs, which would make it hard to breathe in and out. It couldn't just be forced in, it'd have to pressurize the lungs themselves because the problem with altitude is the lower pressure making it harder to absorb oxygen.
The thing about pure oxygen (or diluted oxygen per a diluter demand mask), is that you get the same or more oxygen into the body with the lower pressure in the lungs because of the higher % of oxygen now in the air. Inserting a tube into your mouth wouldn't work because you would still end up with ambient pressure in your lungs. A pressurized air system would have to be sealed around your face and even then I would think it'd be hard on the body.
Title: Re: Higher Altitudes and O2
Post by: tundra_flier on September 27, 2006, 08:28:33 PM
Quote
Nasal masks or pillows might create a problem with communications. The pilot's microphone normally sits immediately in front of their lips. Everytime I've seen a pilot with a headset, that's where the microphone has been. With pressurized air in the nasal passageway, that means there will be a gust of air each time the pilot opens his mouth to speak into the microphone, and it could create unwanted interference, unless there was a dampener on the microphone. Still, if someone isn't used to the mask, it is unusual to try and speak with air rushing out of one's mouth.
Communications wouldn't really be a problem, you'd just have to use a throat mic. They're used with many hands free phone systems, and were used by WWII bomber crews because of the oxygen mask. I am curious how that would work with the ear drums though. With higher pressure in the respiritory tract than ambient. I'd think it'd be like doing a fast decent, except you couldn't pop your ears. :(
Phil
Title: Re: Higher Altitudes and O2
Post by: Baradium on September 27, 2006, 08:42:16 PM
Communications wouldn't really be a problem, you'd just have to use a throat mic. They're used with many hands free phone systems, and were used by WWII bomber crews because of the oxygen mask. I am curious how that would work with the ear drums though. With higher pressure in the respiritory tract than ambient. I'd think it'd be like doing a fast decent, except you couldn't pop your ears. :(
Phil
I believe the system he is thinking of is just a steady stream of air, not pressurizing your lungs. And therein lies the problem, you wouldn't fix the reason for the oxygen requirement. Seems the only way to make it work would be a pressure suit... which is decidedly invonvenient. Diluter demand masks mix ambient air with the oxygen flow at a variable rate depending on altitude so that you use less oxygen at the lower altitudes (since you don't need it all).
In our case, we have two settings, we have a pressure demand setting and a continuous flow setting. The first setting only flows oxygen when you breath in (so when you breath out it allows outflow into the cabin. The second setting always flows oxygen to eliminate the possibility of outside air seeping into the mask in cases such as smoke in the cockpit etc. The disadvantage to that setting is that now to breath out you have to overcome more pressure to force air outside the mask.
The passenger emergency masks in our case are deployed by a valve, when oxygen flows to them it pulls a pin from the pressure which pops the cover and deploys the mask. Pulling the mask to your face further pulls another pin to start oxygen flowing to that mask.
In the big jets, the deployment is automatic based on cabin pressure altitude and each mask has its own oxygen generator that is activated by pulling a pin when you pull the mask to your face.
Title: Re: Higher Altitudes and O2
Post by: fireflyr on September 27, 2006, 11:51:18 PM
Oh, hehe. Yes, pressurized cabins are definitely pressurized ambient air, but that's not what I had meant.
My curiosity was for aircraft that can make it to those altitudes that might not have a pressurized cabin. Let me try again.
I work as a sleep lab technician. Most of the time, I am treating Sleep Apnea. For patients who have sleep apnea, they are prescribed a mask that fits over the nose, or the nose and the mouth. This creates pressurized ambient air in the nasal passages, or nasal and oral passages locally on the person. The rest of the body doesn't experience any kind of pressurized air.
What I was thinking is how useful it would be to develop a similar system as a way to provide an air supply to a pilot in flight who might not have a pressurized cabin, and might not have an easy time of finding a supplier of compressed O2, or would rather pay a higher cost upfront than have to always pay for the service to recharge his O2 tank.
As I think about it more and more, I'm beginning to doubt it's viability as a replacement for O2 for pilots. O2 can be delivered via a simple cannula. The pressurized air is delivered via a mask, or at best, by bigger tubing that fits in the nasal passages, called "Nasal pillows". While you wouldn't have to recharge your O2 canister, you would likely have to recharge a battery. This battery would likely have to be somewhat bulky to carry sufficient charge over a sustainable amount of time. Weight would likely be at least as much as an O2 canister, if not heavier.
Getting back to the mask, this could be problematic. I know pilots without perfect vision who opt out of wearing glasses because of limited visibility where the frames of the glasses lie in their field of view. The mask does sit somewhat in front of the eyes. Nasal Pillows don't, but I'm about to touch on the disadvantage with those.
Nasal masks or pillows might create a problem with communications. The pilot's microphone normally sits immediately in front of their lips. Everytime I've seen a pilot with a headset, that's where the microphone has been. With pressurized air in the nasal passageway, that means there will be a gust of air each time the pilot opens his mouth to speak into the microphone, and it could create unwanted interference, unless there was a dampener on the microphone. Still, if someone isn't used to the mask, it is unusual to try and speak with air rushing out of one's mouth.
Further considerations are the effects of the pressure on a person's ears. This is especially important in flight, and at higher altitudes. It could cause more problems than it fixes.
I guess I answered my own question. :)
Isn't that sort of like talking to yourself---had that problem and the nice people at Shady Rest took care of me for a while, but I'm- f i n e n o o o w ! :-X
Title: Re: Higher Altitudes and O2
Post by: spacer on September 28, 2006, 04:53:41 AM
You don't need to increase the actual pressure, just bring the oxygen percentage up until it supplies the same relative gas pressure from a more 'friendly' altitude. That's the beauty of cannulae. My grandpa preferred a cannula to a mask, as it was easier to smoke with it on. He had emphysema... but not for long. :(
Title: Re: Higher Altitudes and O2
Post by: TheSoccerMom on October 28, 2006, 05:56:03 AM
I learned a surprising lesson once when I planned a flight with enough oxygen for 7 people, with extra for a few unforeseen changes in altitudes at the hands of ATC, etc., and then threw in "extra" in case our mission took us further than we'd planned. I thought I had every angle covered. I briefed everyone, and we had agreed-upon altitude call-outs over the intercom, which everyone was on. Buddy checks were a must; we all agreed to the plan, and we headed out.
Imagine my surprise when we were still in the midst of mapping targets when one of the guys in the rear said the gauge on one of their tanks "was getting low kinda fast". Well, it sure was, and it resulted in having to cancel the remainder of our flight, to RTB.
It turned out a nice young man, who was with an unnamed branch of the military known as the U.S.AIR FORCE, decided, on his own, without telling anyone, that HE "needed" to be on oxygen above 6,000 MSL!!!! He had been briefed, along with the rest of the crew, but back on the ground, he argued that he "was going to be on the safe side", so just cranked it up. He never mentioned a word to anyone, until after we landed prematurely, without having finished the targets.
I was so irked at his attitude that I was standing there, jaw hanging down, trying to figure out how to rip into him and yet sound semi-diplomatic, when I was saved the whole exercise, because the head of the mission jumped in and did it for me. We had flown around at 6500 feet for almost 2 hours, before we climbed up to FL200, so he had really wasted a big chunk of our oxygen.
Anyway -- it was a lesson for me, that briefing is only as good as the brains receiving the information. He was sure he'd be hypoxic at 6,000, and I just wish he would have SAID something. He wasn't even 30, and he was a non-smoker, so it's not like he had a special need.
I found it especially surprising, because it came after flying on fires in the western U.S., where ground elevations range from 8,000 - 12,000 feet EASY. My own perceptions, and habits, prevented me from seeing this one coming!
So.... monitor your O2 and always double-check.... I was so thankful I had a sharp scientist in back, to catch the imminent shortage.
huff, puff... ;)
Title: Re: Higher Altitudes and O2
Post by: undatc on December 05, 2006, 08:02:06 PM
I know here at UND, we have many regs that we have to fly by, in addition to regular FAA regs. Most of them are from accidents we have had, and generally are good practice.
Any flight here that spends more than 30min above 10,000' and is a day flight, must have oxygen on board, and all passengers on. It less than reg's but its safe. Night flights our regs give us 7,000' and above.
And smoking does effect hypoxia, quoted from the Jepp book, "There are 4 types of hypoxia, Stagnant Hypoxia, Hypoxic Hypoxia, Hypemic Hypoxia, and Histotoxic Hypoxia." Smoking would fall under Hypemic Hypoxia as one of the main byproducts of smoking is CO2 which is easier to connect to the cell receptors in your hemoglobin then O2. Because the CO2 molecule is attached, the oxygen cant, which results in a lack of ability of your cells to carry oxygen. From the Jepp book again, "...smokers who smoke an average of 3 cigarettes a day experience a simulated altitude of 4,000msl while still on the ground."
UND has a pressure chamber, and I've taken the course that uses it. It is definately worth doing, if you get the oppurtunity to take a 'flight' in one, do it.
Title: Re: Higher Altitudes and O2
Post by: Gulfstream Driver on December 05, 2006, 09:21:23 PM
And smoking does effect hypoxia, quoted from the Jepp book, "There are 4 types of hypoxia, Stagnant Hypoxia, Hypoxic Hypoxia, Hypemic Hypoxia, and Histotoxic Hypoxia." Smoking would fall under Hypemic Hypoxia as one of the main byproducts of smoking is CO2 which is easier to connect to the cell receptors in your hemoglobin then O2. Because the CO2 molecule is attached, the oxygen cant, which results in a lack of ability of your cells to carry oxygen. From the Jepp book again, "...smokers who smoke an average of 3 cigarettes a day experience a simulated altitude of 4,000msl while still on the ground."
Or CO. Just a little different. ;)
Title: Re: Higher Altitudes and O2
Post by: fireflyr on December 05, 2006, 09:22:18 PM
WOW, Thanks for that----settles several issues I've wondered about---Thanks |:)\
Title: Re: Higher Altitudes and O2
Post by: Baradium on December 05, 2006, 09:40:33 PM
Part 121 requires O2 for the flight crew at any time above 10,000 ft.
Part 135 requires O2 for any time over 30 minutes above 10,000 ft.
In both these cases PAX have different rules as welll, but it's pretty close to the 12,500 rule (has to do with percentages).
undatc, personally I'd refer to those as additional "rules" not regs, since they aren't required by the FARs. Helps stop confusion.
Is there any more news on this recent UND crash (in a non UND aircraft)?
MTSU requires you to wear jeans or other long pants while flying, for the same reasons.
Title: Re: Higher Altitudes and O2
Post by: Gulfstream Driver on December 06, 2006, 05:53:36 PM
UND Policies and Procedures. Know them. Love them.
No new real news out of Crookston on that crash. The airport manager for Crookston told the paper it was definitely the weather, but you know how official that is. The NTSB should have a preliminary report by Friday, so look for that on their web site. I've been trying to keep up with it, but the Grand Forks Herald doesn't seem that interested anymore.
From the pictures, it looks like a stall/spin accident. I was thinking it might be CO poisoning that caused it. The state Medical Examiner in St. Paul is doing autopsies on the bodies, which were both found inside the plane.
Is that MTSU rule only for winter flying? What's the reasoning behind it?
Title: Re: Higher Altitudes and O2
Post by: undatc on December 06, 2006, 08:20:54 PM
Sorry for the misquote there, but for us here, the policies and procedures are basicly just an extension of regs.
And I dont believe the crash in Crookston was a UND plane, at least I havent heard anything about on campus, and I have several CFI friends.
Title: Re: Higher Altitudes and O2
Post by: Gulfstream Driver on December 06, 2006, 08:47:55 PM
It was a Crookston Flight Service 172.
Title: Re: Higher Altitudes and O2
Post by: Baradium on December 06, 2006, 09:19:31 PM
Is that MTSU rule only for winter flying? What's the reasoning behind it?
The rule is year round. MTSU has never had a fatality involving a flight school airplane. Years ago a flight school 152 crashed and the fuel caught fire. The student and instructor maintained that if they hadn't been wearing long pants they wouldn't have been able to get through the flames to get out of the aircraft, or would have been injured much worse if they had. They received only minor injuries and watched the plane burn from a safe distance. Since that point it was flight school policy.
It's important to differentiate from FAA regulations and flight school rules, once you get out of the "flight school world" and into the "real world" you need to know
WEATHER: KCKN 020035Z 32011G16KT 1SM SN OVC002 M07/M08 A2990
Winds out of 320 degrees at 11 kts gusting to 16, 1sm vis with snow.... overcast at 200 ft... not good weather at all...
Title: Re: Higher Altitudes and O2
Post by: Africaspotter on April 03, 2007, 05:43:54 AM
I was at 9,500ft recently and LA Center asked for my altitude. I was looking at my altimeter and I could see the arrow indicating the 10ft steps, but for some reason I could not find the other arrow... :D
I think it really depends on the person and health state, but I personally think that you should stay well below 10,000ft in an unpressurized aircraft. If you think about it, you only get 70% oxygen compared to sea level at 10,000ft... Can't be too healthy.
Cheers,
Felix
Title: Re: Higher Altitudes and O2
Post by: Gulfstream Driver on April 03, 2007, 08:33:41 PM
I was at 9,500ft recently and LA Center asked for my altitude. I was looking at my altimeter and I could see the arrow indicating the 10ft steps, but for some reason I could not find the other arrow... :D
I think it really depends on the person and health state, but I personally think that you should stay well below 10,000ft in an unpressurized aircraft. If you think about it, you only get 70% oxygen compared to sea level at 10,000ft... Can't be too healthy.
Cheers,
Felix
Excellent point. Altitude affects everyone differently. That's why it's good to know your limitations.
Title: Re: Higher Altitudes and O2
Post by: TheSoccerMom on April 04, 2007, 07:14:23 AM
Ditto, Gulf... there are really big differences between people of similar appearance, age, etc. It can be a surprise sometimes! I flew a scientist who informed me she had gotten woozy on an earlier flight, at only 6,000 feet MSL! She didn't smoke, either. And she is quite young. Not the person I would have thought of!
