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Bob Axsom

Well Known Member
I am going to add an oxygen system to the airplane so we can take advantage of its full capability. I have superficially read about such systems for years but I have no experience in this area at all. At Sun 'n Fun we walked through a couple of vendor display hangars (I always find this awkward because I have never prepared to take advantage of the opportunity) and my wife reminded me of the need for an oxygen system. We visited the Sky Ox and Mountain High booths and on the surface they appear about the same with Sky Ox offering a Sun 'n Fun special price of $442 for a 15 CU. FT. two place system complete ready to fly with Cannulas and $35 more for a padded bag (their handout says their normal price for the bagless system is $520). The Mountain High price was on the order of $100 more expensive for the Sun 'n Fun special price. I see Sky Ox is the system featured in Sporty's latest catalog so that gives it some credibility. Both vendors gave me a phone number and said their prices would be good for a couple of weeks beyond Sun 'n Fun although I consider this to be too big a decision to rush for $100 or so.

First question - Is there anything in particular that one should know about either of these systems or any other?

Second - I saw a writeup about a tank mount on the rear of the flap actuator housing which seems easy but accessibility and vulnerability give me some pause any comments on installation experience, recommendations or operational experience related to tank location?

Third - What is the proper and safe way to recharge the tank?

Fourth - What are the in-flight operational requirements for using the system?

Fifth - What are the in-flight operational dangers and the risk mitigations ?

Thanks,

Bob Axsom
RV-6A, N710BJ
 
Oxy Systems

Bob,
I use a "D" bottle system in my "6" I purchased from Aerox and we just love it. I mounted the bottle vertically on the rear flap system brace at the front center of the baggage area. Aerox worked with me and gave me a custom manifold top which has side outlets instead of the standard "y's" out the top, to allow my baggage area cover to still work. The bottle gauge is viewable from the passenger side as entering, so we just check the pressure and turn on the bottle when departing, and leave the ox saving cannulas, and flow meters/valves lying in the area between the seats so they are easy to use when needed.
Living in the West, we have to fly over the Sierra's and Rockys to head east, so having oxygen is really nice... I usually fly up to 14.5k-15.5k and usually put on the oxy passing through about 9k or so. It is really nice to arrive and be clear headed, and also allows us to get above a lot of the turbulance. I think the regs. say "above 12.5 for more than a half hour - pilot must have ox, above 15k both pilot and pass must have on all the time"
We often take some of our small dogs flying with us, and I called Aerox about a little system for them. I figured they would chuckle at my request, but was surprized when they said they get that request a lot. They fixed me up with a little "A" bottle system with two outlets and fixed flow leads and little doggy canulas for them... they only need it if we go real high, and it turned out that our pups don't care to wear the nose deals, so wife has to hold near their nose. It also is nice having the spare "A" bottle at times, if we are just up around 12.5 we can use the doggy bottle as a back up for our "D" bottle, which we have had to do once so far.
As for filling the bottles, Aerox also sold me the filler adapters to fill both bottles, and I fill off my welding bottles at home - not sure if this was best way to go, since the fill cost at FBO's is not that much $$. The only caution for home filling that I know of, it that you must not "shock" fill, and do it very slowly! I got a spare bottle of ox in addition to my welding cart bottle to use as a "topping" bottle. There is much discussion out there about the difference between "aviators breathing" and "welding" oxygen. There is no difference in the actual oxygen - it all comes from the same place. The real difference lays in the quality control of the bottles / filling. With "aviators breathing" oxygen, there are cleanlyness standards for the bottles, where they have to remove the bottle head and inspect the inside of the tank to make sure there is no "muck" in there before they fill it... for only $2 more, cheap insurance to me!
I had a little leak in the valve head in my "D" bottle about a year and a half after purchase... I sent back to Aerox and they fixed, no charge (except for filling and shipping), they have been great to deal with, and did give me a 10% RV discount... call them with the Fun n Sun pricing you got if they were not there, and they may even match it...
Good luck
Dale Wittman, Santa Rosa CA
 
Oxygen

>First question - Is there anything in particular that one should know about either of these systems or any other?

I have had a SkyOx system since Osh last year and like it a lot. We looked at all the vendors and chose Sky Ox, can't really remember why.

>Second - I saw a writeup about a tank mount on the rear of the flap actuator housing which seems easy but accessibility and vulnerability give me some pause any comments on installation experience, recommendations or operational experience related to tank location?

I strap the tank standing up in the baggage comparment just behind the seats. Depending on what you buy will impact whether you need to get to the tank during flight or not. On the Sky Ox system you can adjust the flow before flight but need to plug the canulas into the regulator to start the oxy flowing - so you must be able to get to the regulator in flight.

>Third - What is the proper and safe way to recharge the tank?

Read John Deakin's articles on Avweb (Pelican's Perch). The most I have had to pay is $25 to fill a small bottle (I think its a D size)

>Fourth - What are the in-flight operational requirements for using the system?

The legal requiremens are in the FARs. I would suggest that using oxygen whenever cruising about 9K' for any time will make you feel much better when you land, and the next day. At night consider using it over 5K'.

>Fifth - What are the in-flight operational dangers and the risk mitigations ?

Not entirely sure what you are driving at, most systems are reasonably fool-proof.

Pete
 
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Budget Oxygen Setup

This might help....here is a link to the "Welders Oxygen" article: http://www.avweb.com/news/columns/182079-1.html

And here is what I'm doing (not flying yet). I purchased an aluminum medical oxygen bottle off EBay about 26" x 5" diameter (pretty sure it is E). Enough for a round trip. The only difference in bottles is the size, material it is made of (think weight), and the connection type (CGA-xxx).

Then I picked up a low-flow regulator (0.125 to 1 L/min.) for the medical bottle off EBay. Next I need the hoses and my choice of how I breath it. The nasal oxymizer is the high end passive system that looks dorky but allows you to talk. I can get other systems that are active and sense when you are inhaling or exhaling, but they are double to ten times the cost.

Then I picked up a 'transfiller' to get from a welder bottle (CGA-540) to the medical bottle (CGA-870). The "Welders Oxygen" article goes into these details. Total cost is about $200. Refills are practically free. I plan on trading the bottle in every few years to get a fresh hydrotested bottle.
02-b.jpg

Simple and effective system for a bargain price. Can be refilled practically anywhere, if you bring your transfiller. Good luck on your setup, whichever one you choose.
 
Operational Risks and Mitigation

One respondent needed more information on the Risk and mitigation question so I will brainstorm a few operational risks:

Contamination - If the gas isn't oxygen or it is not the necessary level of purity that could be a fatal operational problem.

Depletion - If you consume the oxygen in flight and are still cruising along at 18,000 ft. that could be a fatal operational problem.

Obstruction - If the supply is blocked by passage deformation or ice that could be a fatal operational problem.

Disconnection - If the supply line becomes disconnected that ...

Explosive failure of pressurized components - ...

Combustion of the oxygen when exposed to an ignition source - ...

Physical injury caused by free flying components in turbulence - ...

I know these are real problems regardless of the general experience with oxygen system usage and I am going to accept the risk and mitigate them as much as possible in a tradeoff against Hypoxia risks. I remember very well when Gus Grissom and the other two astronauts were burned to death in the Apollo fire on the launch pad and the biz jet that flew with no response to communication attempts until its fuel was exausted and it crashed. The oxygen systems have no doubt become very sophisticated since the days of Wiley Post and I will not be flying at the instant death altitude levels anyway but I believe the pilot should know what the risks are, what fault detection devices are available and how they should be used to mitigate these risks.

You folks sure took the time necessary and gave me some good feedback. I feel much better about moving forward with the system in my airplane.

Thanks,

Bob Axsom
RV-6A, N710BJ
 
Oxygen Danger - Pelligro!

One of the things that has not been mentioned yet about oxygen is the danger of contamination of fittings, masks, couplings with petroleum grease.

Having been trained in the use of oxygen in the airlines and testing the systems every day while at work, I got to use it fairly often.

The first thing to know about O2 is that it works great to alleviate remnant hangovers! Just strap on that mask and the headache fades away. Just in case anyone would be silly enough to fly with a hangover. I, of course, only know about this from other silly pilots who have mentioned this to me!

The danger lies in pure oxygen coming into contact with any kind of petroleum grease or oil. The chance of spontaneous combustion is very serious when the aforementioned occurs. This is true of even brylcream or beard oil or grease. So never, never, use grease or oil to lubricate your connections or fittings on masks, hoses, or bottles. Do not even use face cream if you are using a face mask.

So, oxygen can be a double edged sword. It can keep you alive at high altitudes, but it will be dangerous to be near in a crash/fire situation. The airliners of today are using chemical generators for passenger oxygen requirements instead of the bottled oxygen of the older types. Weight comes into the picture of course, but safety also enters the equation. Enough oxygen for 400 people all concentrated in one spot is a fairly lethal stuation in a crash. On the other hand, the chemical generators have already caused an inflight fire in a cargo airplane transporting time-exed chem-generators. Chemical generators produce a fair amount of heat and also cannot be turned off. That is, they continue to operate for 20 minutes whether they are still needed or not.

My recommendation is to be respectfull, cautious and carefull while handling oxygen. Treat it as if it was AVGAS, because it can be more lethal than AVGAS. Consider, that oxygen will promote combustion in almost anything once started, metals included, that's how a cutting torch operates.

Cheers, Pete
 
Bob... oxygen systems are common in sailplanes in the Western US. A lot of desert flying is done from 12K to 18K ft., so oxygen is a necessity.

This dealer has a good catalog for the idividual parts, and is easy to deal with...

http://www.wingsandwheels.com/page35.htm

and

http://www.wingsandwheels.com/page36.htm

One item not mentioned above is a flow meter. This item, combined with a nasal cannula - dorky, but very effective and comforable compared to a mask - will save you lots of oxygen. A standard 22 cu ft bottle is good for about 5-6 hrs. at 15 K ft. with a mask, but good for about 20 hours with a nasal cannula.
With a good sailplane flight being 5 hrs or so (W. desert in summer) this extra capacity makes a big difference and relieves the need for a fill-up between each flight.
Of course two passengers reduce this number by 2...:^)

A piece of velcro can be used to mount the flow meter/flow regulator (buy the one with the needle valve mounted at the base of the flow meter) is a vertical position on the side of the cockpit.

Good luck... gil in Tucson

RV-6A finishing
Grumman Tiger
Mini-Nimbus sailplane - with a self installed O2 system

PS ...Usual disclaimer, no connection to Wings and Wheels, just a happy customer.
 
Wing tip O2

I hope I don't sound stupid here but.... Would it be possible to put a small o2 bottle out on each wing tip and run a line with just a valve in the plane to turn on or off??? I know it would require an easily removeable wingtip but then you wouldn't have the bottle in the cockpit with you. Please forgive me in advance for all the reasons one shouldn't do this

Bill
RV-6 Hope to be flying one day.
 
oxygen in wingtip?

Bill,
Oxygen bottles in the wingtip would surely de-clutter the cabin, but there might be a few problems to contend with. I'd give it some careful thought before running an oxygen line through the wing near the fuel tank... in the vicinity of electrical wires(a source of fuel, a source of ignition, and oxygen inside an enclosure). Also, would the line be low pressure or high pressure? If it were low pressure, then you would need a remote transducer to tell you how much pressure is in the tank(wouldn't want to run out at altitude without knowing). If it were a high pressure line, you wouldn't need the remote pressure transducer but the line would certainly add weight.

I put the O2 bottle next to the rear passenger's seat and it stays put nicely, and it is not difficult to reach back to open the valve. But the tank should probably be anchored somehow, maybe with Velcro straps or something.

Take a look at the award-winning RV8 "Grezdlitn" sometime(it was featured in Sport Aviation). It has a hard-piped O2 system with bottles in the rear baggage area. Most impressive!

Good luck,
Mark
 
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