Safest, most redundant oxygen setup for single pilot or dual occupant in the FL's?

[BlueSky247]

First a "what-if" emergency question:

Let's say we're cruising along at FL22 and the oxygen setup craps out. Assuming you aren't in the mountains, and you have a working AP, wouldn't it be possible to set the AP at a 1500fpm descent to 9,000 before you pass out? Yes, that would be very risky, but we're talking an emergency here - presumably, you'd wake up after levelling off. Or no?

 

So what is the best way to go about ensuring complete redundancy for the FL's? Dual tanks with a pressure alarm on each? A cannula under the mask? Just don't go over FL18 when alone?

 

 

[Fly Boomer]

1 minute ago, BlueSky247 said:

First a "what-if" emergency question:

Let's say we're cruising along at FL22 and the oxygen setup craps out. Assuming you aren't in the mountains, and you have a working AP, wouldn't it be possible to set the AP at a 1500fpm descent to 9,000 before you pass out? Yes, that would be very risky, but we're talking an emergency here - presumably, you'd wake up after levelling off. Or no?

 

So what is the best way to go about ensuring complete redundancy for the FL's? Dual tanks with a pressure alarm on each? A cannula under the mask? Just don't go over FL18 when alone?

 

 

Some people set their altitude pre-select and vertical speed for that eventuality.  You have to realize that you have lost O2, but if you can still push a button, you are on your way down.  Clearly won't work if you are passing over Denver westbound when you have your emergency.

[N201MKTurbo]

Keep one of these in the plane.

[BlueSky247]

6 minutes ago, N201MKTurbo said:

Keep one of these in the plane.

 

 

Sorry, but I have to ask. I have seen those mentioned before, but is that a serious suggestion? We'd sip on that bottle on the way down?

 

[dzeleski]

28 minutes ago, BlueSky247 said:

 

Sorry, but I have to ask. I have seen those mentioned before, but is that a serious suggestion? We'd sip on that bottle on the way down?

 

It definitely is. They work I have used them before in Aspen as my lungs were not built for higher alts (lived at sealevel my whole life). It would still be a critical situation but it would definitely buy you several minutes of consciousness which would 100% let you get out.

One large can supports 200 breaths. We breathe 12-20 times a minute, thats 10 minutes of extra O2. Which is way better then none.

Edited July 31, 2024 by dzeleski

[N201MKTurbo]

38 minutes ago, BlueSky247 said:

 

Sorry, but I have to ask. I have seen those mentioned before, but is that a serious suggestion? We'd sip on that bottle on the way down?

 

Yes, they will fit in the seat backs and are readily accessible. Much better than passing out and waiting to wake up again.

You probably won’t figure out that your oxygen has quit until you are on the verge of incapacitation. Taking a hit of oxygen will keep you going for 30 seconds or so. This will give you time to program your descent and probably keep you going until you are down in the teens where you can breath.

I would suggest finding a PROTE session and take one of these with you and see how long you can go on a bottle at 25K. Besides, the FAA folks will probably think it is cool.

[dkkim73]

I would strongly suggest getting an altitude chamber ride or (2nd choice) a ROBD (reduced-oxygen breathing device) familiarization (FAA version is the PROTE mentioned above, I have not tried that specific version). Knowing your own individual symptoms is a key asset for dealing with this. 

Add to that: 

-monitoring your SaO2 with a pulse ox (I'm using the Wellue ring currently with intermittent checks with a 2nd pulse ox); this won't detect CO poisoning but will detect hypoxic hypoxia, which is the concern with a failing O2 system

-regular O2 system checks in your cruise flow (setting, pressure, flow indicator or confirm the sensation of flow); have a short flow to run if your O2 appears failed or questionable, e.g. "PRICE" (pressure, regular/setting, indication of flow, connectors/kinked tube, emergency setting if you have one). 

-I would imagine the cans would be useful during a descent, not really a full backup system. I'm still looking at that myself. The seat-back style bottle+reg+tubes+masks is probably the best. I'm still trying to decide whether to have a full backup or just another source to plug into, as I use the Mountain High. Simple is good, and maybe the Boost (or some other kind of "bail out bottle") would be easier from a KISS perspective. 
 

[N201MKTurbo]

21 minutes ago, dkkim73 said:

I would strongly suggest getting an altitude chamber ride or (2nd choice) a ROBD (reduced-oxygen breathing device) familiarization (FAA version is the PROTE mentioned above, I have not tried that specific version). Knowing your own individual symptoms is a key asset for dealing with this. 

Add to that: 

-monitoring your SaO2 with a pulse ox (I'm using the Wellue ring currently with intermittent checks with a 2nd pulse ox); this won't detect CO poisoning but will detect hypoxic hypoxia, which is the concern with a failing O2 system

-regular O2 system checks in your cruise flow (setting, pressure, flow indicator or confirm the sensation of flow); have a short flow to run if your O2 appears failed or questionable, e.g. "PRICE" (pressure, regular/setting, indication of flow, connectors/kinked tube, emergency setting if you have one). 

-I would imagine the cans would be useful during a descent, not really a full backup system. I'm still looking at that myself. The seat-back style bottle+reg+tubes+masks is probably the best. I'm still trying to decide whether to have a full backup or just another source to plug into, as I use the Mountain High. Simple is good, and maybe the Boost (or some other kind of "bail out bottle") would be easier from a KISS perspective. 
 

I wasn't suggesting the Boost cans for a backup per se. They were for an emergency descent. I can only think of two flights where they would have been a problem. Well really only one. Once I was at FL200 over an area of severe icing over the mountains. Descending was not an option. I would have to go about 50 miles before I could descend, One Boost wouldn't be enough. The other occasion, I was at FL190 over T storms, but I could have descended after 5 min or so.

I could probably do FL190 all day. In the PROTE I made it to the end of 5 min at FL250 without oxygen, but I couldn't make it much further. I was gasping for air quite a lot. It was very uncomfortable. 

[BlueSky247]

@N201MKTurbo Just curious - would you consider yourself fit, with an active workout schedule? I'm just curious because I personally have seen times where I could hold my breath for nearly five minutes without issues. Obviously, that would take not being stressed in the cockpit and being able to stay focused and calm.

 

@dkkim73 Thanks for the recommendation. I'm absolutely planning to do  PROTE or whatever I can find. I do like that mountain high pulse system. I bet they would be happy to design/sell a setup with dual regulators and tanks, etc. 

 

In any case, I would absolutely be wearing some kind of ox monitor before I attempt this. One thing that would be helpful would be to simply increase cruise altitude by one thousand foot intervals while watching that monitor to see when the deprivation starts kicking in. Obviously, with a safety pilot along already wearing a system. 

 

Really appreciate everyone's thoughts. I'm hoping to pick up a J soon and looking forward to taking some epic trips in it. Being able to really leverage winds aloft would be nice.

[N201MKTurbo]

50 minutes ago, BlueSky247 said:

@N201MKTurbo Just curious - would you consider yourself fit, with an active workout schedule? I'm just curious because I personally have seen times where I could hold my breath for nearly five minutes without issues. Obviously, that would take not being stressed in the cockpit and being able to stay focused and calm.

 

@dkkim73 Thanks for the recommendation. I'm absolutely planning to do  PROTE or whatever I can find. I do like that mountain high pulse system. I bet they would be happy to design/sell a setup with dual regulators and tanks, etc. 

 

In any case, I would absolutely be wearing some kind of ox monitor before I attempt this. One thing that would be helpful would be to simply increase cruise altitude by one thousand foot intervals while watching that monitor to see when the deprivation starts kicking in. Obviously, with a safety pilot along already wearing a system. 

 

Really appreciate everyone's thoughts. I'm hoping to pick up a J soon and looking forward to taking some epic trips in it. Being able to really leverage winds aloft would be nice.

I am fairly fit. I exercise a few days a week. I ride about 40 miles a week. 
 

While I was in the chamber, I was practicing a breathing method that I read about, and I practice sometimes at altitude to increase my SpO2 while wearing the pulse ox. It involves deliberately exhaling as thoroughly as possibly and then filling your lungs as much as possibly. By doing this I can increase my SpO2 by 5% or so. 

[IvanP]

I use pulse oximeter (Wellue Ring) to monitor sat levels (vibrating alert as the audio alert is useless in Mooney cockpit) and Skyox portable system in the back seat as a back-up for the ship's system. My main system in Bravo has the O2D2 on-demand regulator that will let you in know immediately if your O2 system is malfunctioning. The O2D2 box has adudio and visual warning. and you can also hear and feel the puffs of oxygen when in use. With constant flow systems, you have to look at the flow meter to see if oxy is flowing. Some people find listening to the puffs form O2D2 annoying, but I like it as a constant monitoring of the system.   So far, I have not had the need for back-up system, but it is there, just in case.

[Fly Boomer]

4 hours ago, BlueSky247 said:

 

Sorry, but I have to ask. I have seen those mentioned before, but is that a serious suggestion? We'd sip on that bottle on the way down?

 

Or if you are a belt and suspenders type, I have 115 cu ft in the tail, a "D" size medical cylinder, and a Boost can.  Just in case.  I don't want to deal with the medical cylinders on a regular basis, but with one on board, it might get me out of a jam.

[EricJ]

4 hours ago, N201MKTurbo said:

I would suggest finding a PROTE session and take one of these with you and see how long you can go on a bottle at 25K. Besides, the FAA folks will probably think it is cool.

It counts as Wings credit.    Definitely worthwhile to do for anyone who gets the chance.     

[exM20K]

+1 on the PROTE session.  Know your symptoms.

mountain high used to sell a set of 8” O2 bottles with a regulator and over-the-nose/mouth mask. Can’t find pics online.  Their supplier for the bottles went out of business, so that product is no longer available.  Pity.  I still have mine standing by in the right map pocket.

Boost would get you down if you’re aware of your symptoms and act quickly.

My O2 setup has the most points of potential failure of any system on the plane, and I monitor it accordingly.  I’m in pretty good shape (1-5 bike rides weekly from 15-25 miles), but in the PROTE chamber, I was useless and playing with yarn long before some of the younger guys quit doing differential equations.

- dan

[Ragsf15e]

5 hours ago, BlueSky247 said:

@N201MKTurbo Just curious - would you consider yourself fit, with an active workout schedule? I'm just curious because I personally have seen times where I could hold my breath for nearly five minutes without issues. Obviously, that would take not being stressed in the cockpit and being able to stay focused and calm.

 

@dkkim73 Thanks for the recommendation. I'm absolutely planning to do  PROTE or whatever I can find. I do like that mountain high pulse system. I bet they would be happy to design/sell a setup with dual regulators and tanks, etc. 

 

In any case, I would absolutely be wearing some kind of ox monitor before I attempt this. One thing that would be helpful would be to simply increase cruise altitude by one thousand foot intervals while watching that monitor to see when the deprivation starts kicking in. Obviously, with a safety pilot along already wearing a system. 

 

Really appreciate everyone's thoughts. I'm hoping to pick up a J soon and looking forward to taking some epic trips in it. Being able to really leverage winds aloft would be nice.

It (hypoxia) is not at all related to how long you can hold your breath.  That just isn’t how it works.  The partial pressure of oxygen is much less at high altitude and the oxygen is basically being pulled out of your blood through your lungs and not being replaced in sufficient quantities.  Holding your breath is no indication of what will happen to you if you lose O2.  You really need an altitude chamber ride (and the class).

[Ragsf15e]

13 minutes ago, exM20K said:

+1 on the PROTE session.  Know your symptoms.

mountain high used to sell a set of 8” O2 bottles with a regulator and over-the-nose/mouth mask. Can’t find pics online.  Their supplier for the bottles went out of business, so that product is no longer available.  Pity.  I still have mine standing by in the right map pocket.

Boost would get you down if you’re aware of your symptoms and act quickly.

My O2 setup has the most points of potential failure of any system on the plane, and I monitor it accordingly.  I’m in pretty good shape (1-5 bike rides weekly from 15-25 miles), but in the PROTE chamber, I was useless and playing with yarn long before some of the younger guys quit doing differential equations.

- dan

Yeah im fit too and not too old, but my Oxy sat drops faster than my wife and kids.  People are different.  It’s not really a fitness thing (although that can make it worse). I used to do the altitude chamber in the Air Force, and I would pretty much do five minutes, see my symptoms, and put the mask right back on. No reason to play around up there, I just didn’t feel good. Some people start to feel so euphoric that they keep it off for a long time and try to see how long they can make it. By the end they have no idea what they’re doing.

[Pinecone]

14 hours ago, N201MKTurbo said:

While I was in the chamber, I was practicing a breathing method that I read about, and I practice sometimes at altitude to increase my SpO2 while wearing the pulse ox. It involves deliberately exhaling as thoroughly as possibly and then filling your lungs as much as possibly. By doing this I can increase my SpO2 by 5% or so. 

Another thing to help is to exhale against mostly closed lips.  This increases the air pressure in your lungs, which helps.

 

[Pinecone]

First, you must learn YOUR hypoxia symptoms and altitude tolerance.  And it changes over time.  When I did the chamber in USAF UPT, at 25,000 they gave up on me.  I was woosie, but function even after 5 minutes.  

OTOH, I was doing a flight at 13,500 for under 30 minutes (oxygen not legally required).  I was fine.  The guy in the right seat was flying, under the hood, and I noticed his head swaying and bobbing.  And when I asked, he was slurring his words.  The guy in the back was OUT.  Got over the line of clouds and started back down.  Guy in the right seat was fine by 12,500.  Guy in the back woke up around 11,000.  But these days, I can feel slight symptoms at 9,000.  So I am O2 over 8,000, unless it will be a very short time.

Second, I also highly recommend the O2D2.  You use much less O2 with this, so you will use it more often.  And it delivers and pulse of O2 at the start of inhalation, so it gets deeper in the lungs.

As for backup, the best back up would be a small bottle with a mask.  A mask as it is more effective delivering the O2 to you.

The canned air is a nice to have to use to get your backup in operation.

Third thing is, one of the first things to go when you are slightly hypoxic is color vision and acuity.  At night I am on O2 over 5,000 feet.

[Fly Boomer]

14 hours ago, exM20K said:

I was useless and playing with yarn long before some of the younger guys quit doing differential equations.

Laughed out loud.  Thanks.

[Fly Boomer]

3 hours ago, Pinecone said:

At night I am on O2 over 5,000 feet.

+1

[Marc_B]

https://www.faa.gov/documentLibrary/media/Advisory_Circular/AC_61-107B_CHG_1.pdf

The time of useful consciousness that the FAA uses (see page 24 in AC above) is based on explosive decompression.  So I don't think this would quite be the same as running an oxygen tank dry or accidentally kinking/disconnecting oxygen tubing.  But I absolutely agree with @Pinecone that you should get hypoxia training to learn your personal symptoms.  Early identification of an issue is one of the most important principles of high altitude flight. 

Also, having one (or two pulse oximeters) readily available and used regularly when flying at altitude should be SOP for any pilots flying at altitude in unpressurized aircraft.  You will likely pick up hypoxia earlier with a pulse ox then you would with dependence on symptoms.   For many people, once you are symptomatic you are already in trouble.  However others may tolerate hypoxia much much better...but there are variations from person to person and even individually from day to day.  If you're tired, dehydrated, ill, stressed, etc. you may respond dramatically different than if you were 100%.  Fly with a quality pulse oximeter and use it often at altitude.

But if you find you are hypoxic or having symptoms of hypoxia, you want to immediately descend as this is truly an emergency especially in the flight levels where you can expect your blood pulse ox to equilibrate very low.  A rapid descent should be the first step in your emergency checklist.  Honestly I'd be apprehensive of getting comfortable with having a "back up" in the back seat to convince myself that if I run into issues I can get all this set up faster than I could get to a more lung friendly altitude.  If I'm having any oxygen issues, I'm descending to a lower altitude, end of story.  There are very few places most pilots fly here in the US, that wouldn't allow this.

Also one other thing to point out, is that hypoxia and carbon monoxide exposure have lots of overlapping symptoms.  So don't forget about CO if you're feeling symptoms of hypoxia.  With CO poisoning your pulse ox will be unreliable and won't show you the critical nature of what's happening.

So fly with a sensitive, high quality CO monitor and fly with at least one (or two) high quality pulse oximeters...and truly understand that hypoxia and CO poisoning are both emergency conditions and require quick action.

3 hours ago, Pinecone said:

one of the first things to go when you are slightly hypoxic is color vision and acuity

I did the FAA Hypoxia and survival training at OKC last month and surprisingly my color vision didn't seem to be affected.  The staff at CAMI said that about 50% of pilots have a color response with hypoxia and 50% don't.  This time I intentionally looked at the color wheel right before putting on my oxygen mask at the end of the hypoxia chamber time and to me it didn't look any different/vibrant/dim/etc.  Some describe dull colors or monochromatic colors that then become vibrant with return of normal oxygen.  Certainly your retina has a high metabolic rate and uses oxygen and is more sensitive to hypoxia in general.  But that wasn't a symptom that I can personally rely on.  But hypoxia isn't the same for everyone which is all the more reason to find a PROTE near you and find out your symptoms.

[Marc_B]

23 hours ago, BlueSky247 said:

So what is the best way to go about ensuring complete redundancy for the FL's? Dual tanks with a pressure alarm on each? A cannula under the mask? Just don't go over FL18 when alone?

Preflight to ensure you have enough oxygen for the trip duration, flow rate, and number of people on oxygen.  Monitor your pressure gauge to ensure this isn't changing unexpectedly.  Have a pulse ox and check your pulse ox every 10-15 minutes scheduled, and immediately if you have any questionable symptoms or concern.  Pay attention to the others in your aircraft to see how they are functioning in case they are having issues.  Descend immediately with any concerns for hypoxia or oxygen issues.

I have an O2D2 as well and so this has alarms for oxygen flow as well as not sensing breaths.  I also find the puffs of air reassuring to suggest my oxygen is flowing.  But at altitude (not just in FL) I'm routinely checking pulse ox and keep one hanging from my prop knob 100% of the time.  Any question is a quick and easy check.

[Pinecone]

I agree that losing your O2 delivery in the mid teens or higher is an emergency.

My "checklist" for this would be to set up an autopilot descent to the lower practical altitude FIRST.  You do not need to go to 9000. It does not help to have O2, but hit a mountain..  

If you have a Boost can, use it to sharpen up to set up the descent, call Mayday (YES this is an emergency) and tell ATC.

THEN, don the mask and turn on your portable bottle.  Again, if you have a Boost can, a hit or two will help you manage this task.

[BlueSky247]

Thanks Guys. 
 

So from a flight ops perspective, what is the safest descent rate we could automate and how would you configure mp/power levels? Or is that something a decent AP would have safeguards built in for? (This is assuming we are at risk for passing out and want to use the AP as a safety net.)

[EricJ]

3 hours ago, Marc_B said:

I did the FAA Hypoxia and survival training at OKC last month and surprisingly my color vision didn't seem to be affected.  The staff at CAMI said that about 50% of pilots have a color response with hypoxia and 50% don't.  This time I intentionally looked at the color wheel right before putting on my oxygen mask at the end of the hypoxia chamber time and to me it didn't look any different/vibrant/dim/etc.  Some describe dull colors or monochromatic colors that then become vibrant with return of normal oxygen.  Certainly your retina has a high metabolic rate and uses oxygen and is more sensitive to hypoxia in general.  But that wasn't a symptom that I can personally rely on.  But hypoxia isn't the same for everyone which is all the more reason to find a PROTE near you and find out your symptoms.

So what were your symptoms?    The main value of the PROTE exercise, as they say during the exercise, is so that one can determine what their own primary and secondary symptoms are.    My primary symptom is just a bit of dizziness, which, fortunately, I'm typically very conscious of and recognize as potential onset of impairment.   What I didn't know until the exercise was that that's really the only symptom I get before I start getting impaired.   Like you, my color vision was essentially unaffected, but I did find out that my fine motor skills go to complete crap.   I was doing the puzzles, and could still figure out what to write down, but I couldn't get my hand and fingers to write it in any sort of recognizable form.   It was really interesting.   So if I want to know if I'm really getting impaired, I need to try to write things down...derp.   

It's fun and interesting to do the exercise with a group of people so that you can see the diversity of symptoms and responses.   The debrief with the group was nearly as interesting as the exercise.