Oxygen systems

We're installing a Mountain High Pulse Demand oxygen system with the kevlar tank in the RV-10. Does anyone have photos of an install like this?

I did it and it is the best addon I did. I am not much for taking pictures so......but I will see what I can dig up. I stole someelse's design......I will find that also.

Try this link..

http://www.myrv10.com/tips/accessories/oxygen/index.html

I used this as a guide, but after some discussions with a couple of ME's at work, I just put some doublers on the bulkhead running across from the center support to the outsid bulk head. My tank is in the same location as Randy.

Here's a better link...Robin has some neat ideas..

http://www.painttheweb.com/rv-10/aeroxO2.htm

I don't know who that guy is but I would like him to plan, my panel! Seriously is he taking up any consulting right now. Thats pretty much what I had envisioned.


Now where is that money? I had it around here some where.

Battery next to O2 source?

This is EXTREMELY unwise.

HAZARD!!!

Installing the battery and oxygen tank this close to each other results in an extremely hazardous condition. We lost three astronauts in the Apollo 1 fire because of a small spark in an Oxygen environment. Everyone thought beforehand that it was a controlled and safe situation.

The really sad part is that six years before, the Soviets lost a cosmonaut in a ground test when an alcohol swab came into contact with a hot plate causing an intense fire. Because of the space race, they didn't tell the world about their tragedy.

Please reconsider the location of your battery and your Oxygen tank!!!

Oxygen is our friend, but if mistreated, it can become our worst nightmare!

Don

P.S. The more I think about this, the more concerned I get. Granted, airplanes have been flying around for years with O2 systems onboard. But if enough oxygen leaked from a line, valve or regulator and just one spark occurs in the O2 rich environment, then there is a problem. If you think aluminum won't burn, just consider that the FUEL of the Space Shuttle solid rocket boosters is ALUMINUM. That's why the solid rocket boosters' exhaust is so visibly bright. The experimental amateur built certificate of airworthiness gives us a lot of freedom, but with that freedom comes responsibility. If someone will show me a spam can that is certified with an oxygen system as close to the batteries as Mr. Marks' is, then I'll shut up.

rv7boy said:

Installing the battery and oxygen tank this close to each other results in an extremely hazardous condition. We lost three astronauts in the Apollo 1 fire because of a small spark in an Oxygen environment. Everyone thought beforehand that it was a controlled and safe situation.

The really sad part is that six years before, the Soviets lost a cosmonaut in a ground test when an alcohol swab came into contact with a hot plate causing an intense fire. Because of the space race, they didn't tell the world about their tragedy.

Please reconsider the location of your battery and your Oxygen tank!!!

Oxygen is our friend, but if mistreated, it can become our worst nightmare!

Don

P.S. The more I think about this, the more concerned I get. Granted, airplanes have been flying around for years with O2 systems onboard. But if enough oxygen leaked from a line, valve or regulator and just one spark occurs in the O2 rich environment, then there is a problem. If you think aluminum won't burn, just consider that the FUEL of the Space Shuttle solid rocket boosters is ALUMINUM. That's why the solid rocket boosters' exhaust is so visibly bright. The experimental amateur built certificate of airworthiness gives us a lot of freedom, but with that freedom comes responsibility. If someone will show me a spam can that is certified with an oxygen system as close to the batteries as Mr. Marks' is, then I'll shut up.

Click to expand...

I'm a heating contractor. I deal with natural gas, ignitors, etc.
At the moment, I'm not yet "freaking" out in regards to this installation.
Yes, there is some potential that a spark might exist, and the fact that an oxygen rich enviroment can make things burn faster. But we're certainly not talking aluminum dust as the flammable material; and quite frankly, I don't see much difference in moving the oxygen forward of the bulkhead or behind. Afterall, it's not like these bulkheads are totally sealed from the aft fuselage section.

Personally, I'd worry much more about my engine compartment going up in flames, than this installation.

P.S. --- I just realized that my 6A has it's battery in the cabin along with my fuel lines, aux. fuel pump and tank selector valve. My oxygen system is just behind the seat in the same cockpit. What about those batteries stuck on the firewall in the engine compartment?

L.Adamson --- RV6A

Changing Gears

To change gears a bit, I'm interested in the installation on the other end of the system.

-- If you are or planning to use bulkhead style outlets, where are you mounting them? I plan on having both and overhead and a center console so there's lots of mounting possibilites but having never used O2 I don't know what is a practical solution. For example, I could easily mount outlets in the overhead, but would having O2 tubes hanging down when in use be a nuisance?

-- What kind of tubing (metal vs plastic) are you using to plumb the system from the tank to the outlets?

Bob, I had been pondering this a bit for my own 10, I keep looking at the baggage floor, tucked into the wedge shape area at the front where the rear seat back attaches. Mount horizontally, valve to the centerline of the AC.

Should stay out of the way, yet allow good access to the valve.

Another data point...

I am not sure at this point how I feel (or should feel) about an oxygen tank in the tail cone adjacent to the battery, but it does bring to mind a recent Lancair IV accident that would make me have to really think about it for a while.

Here is a link to the salvage sale page with photos http://www.aigaviation.com/aviationsalvage/salvagedetail.aspx?faano=N731SJ

Link to NTSB prelim report
http://www.ntsb.gov/ntsb/brief.asp?ev_id=20080922X01515&key=1

Short story...Battery fire in aft tailcone. I don't know where the emergency O2 bottle (I would assume it has one) for a Lancair IX P is located, but I have a feeling it was not in the tail cone (on this airplane at least).

Security

As a former EMT who has come upon a lot of accidents involving high speed impacts of gas cylinders and batteries, and who used to travel with oxygen cylinders along a lot of rough country roads...I think the most important thing is to make sure the two systems are secured well. The tail section of an airplane is usually the part that survives impacts the best...and I've seen a number of wrecked Cessna's with batteries in the back where the battery was OK...untouched even, where the occupants were not OK. One of the safety rules of storing high pressure gas cylinders (oxygen or CO2 or argon or whatever) is to always make sure the cylinder is secured well, ostensibly to prevent an impact from damaging or breaking the valve. The cylinder itself is pretty bulletproof, but you because of its mass, you don't want it rattling around. I think the same goes for a battery...especially the Odyssey's most of us are using. They are pretty well built, they don't tend to leak or outgas like the old timey wet cell batteries...but they do need to be very secure, as do their connections! I'd be a lot more concerned about a fuel leak in fuel lines in the tunnel and in proximity to static electrical discharges than I would be some O2 floating around in an (unfortunately!) well ventilated RV cockpit. Hey, at least we're not building ash trays in our RV's like a few of my old '60's era Cessna's had!!!

Most STC'd aftermarket O2 systems for certified aircraft put the cylinder in the tail (where the battery is on 24V Cessnas). I plan on putting my O2 cylinder in the tail, for both practical and CG reasons...consulting the manufacturer for proper selection of high quality lines, sealing them properly and inspecting the system regularly...the same as I do with the fuel lines that are all around me in the cockpit...

In my -7, I strap a portable O2 cylinder to the back of the flap motor brace...and I've often thought about O2 in the cockpit as I unplug my various handheld devices from the 12V power source or run the flap motor...but so far, no kaboom.

Like all the hazards we fly with, this one should be identified, examined, analayzed and dealt with properly.

Auburntsts said:

To change gears a bit, I'm interested in the installation on the other end of the system.

-- If you are or planning to use bulkhead style outlets, where are you mounting them? I plan on having both and overhead and a center console so there's lots of mounting possibilites but having never used O2 I don't know what is a practical solution. For example, I could easily mount outlets in the overhead, but would having O2 tubes hanging down when in use be a nuisance?

-- What kind of tubing (metal vs plastic) are you using to plumb the system from the tank to the outlets?

Click to expand...

I used the mountain high system and it has pulse demand distributors for each station. They are not small, you need to consider the system you are using, since it will drive where you can put the fittings.

The MH system comes with plastic tubing, each to work with.......

The MH system is.......$$$$$$ >$6,000

I have been working/using oxygen systems in aircraft and industrial equipment since 1978.

I did not cite any examples of problems because I knew the posters would make up all KINDS of excuses/reasons why this will be OK.

If you are flying your aircraft and the battery causes a fire in close proximity to your O2 system, you will die.

So, if you think you are lucky, proceed. Good luck to you.

Building a 7a but my previous ride was a 91 Mooney TLS~ BRAVO. MOONEY installed two 24V batteries within two feet of a 115 cu ft kevlar O2 bottle. Contactots and remote avionics in the same compartment aft of the baggage compartment. Combustion requires fuel, O2 and ingition - all in the same place at the same time. I would not consider an aux fuel tank on the same location. Pls excuse the blackberry mispellings...

It was a given that some people will not get over having O2 that close to a battery or an electrical connection of any type...but in the certified aircraft world, just take a look at how these systems have been installed for 20 years. Find a few examples of O2 systems blowing up and let's analyze them...I looked for some examples and couldn't find them. I'm not trying to be in denial here, I'm asking for input. If you really think that its unwise to have an O2 system in an aircraft, I don't think that's a view supported by problems observed in certified installations. So lets make ours like certified installations...that was my point.

Having decided long ago to locate the oxygen cylinder in the tail cone, I don't wish to reopen that part of the debate. I do, however, have another issue which I'd like opinions on, especially DAR opinions (listening, Mel?). Because I have the air conditioning system on a tray above the longerons, I can't do a vertical install like Randy did (see link on iflyrv10). No problem; plenty of room to do a fore/aft install. But I wanted the cylinder on the right side of the fuselage so I'd have easier access to the battery and master solenoids and I can easily run the O2 filler where I want. But then I looked at the TruTrak servo and wondered about acceptable clearance. Below is a photo with the cylinder in position as far left as I can and the servo held in position above the bracket; it would actually be one inch lower. The lateral clearance is two inches as shown by the ruler. You are looking aft at the bottom of the tail cone.



I can't imagine anything closing that lateral distance that wouldn't be as catastrophic already as the servo hitting the cylinder, so I'm not really worried about danger. But I want to be sure it will pass inspection in that location. Should I be worried?

oxygen in rv-10

I'm just finishing up my installation, MH system in the RV-10, mounted in tailcone, horizontal orientation. Here's a link to my picasa site.

http://picasaweb.google.com/rcnewman64/OxygenSystem#


Bob Newman
40176,
TCW Technologies

Bob, no offense, but I don't find your installation acceptable. The datasheet that came with the mounting system lists the G load limits in all directions and the lateral load limit is very small. You've got it aligned in the vertical direction, which is where most of the loads go when maneuvering. I think you should add support under the bottle; perhaps build a shelf supported diagonally to the side or the bottom. I've considered the same but prefer to follow the KISS rule and keep the additional structure minimal.

Thanks for the advice, I did look at this in deciding the mounting orientation and the bracket I designed. The side loading allowed by the MH instructions is 2-4 Gs, I added large fender washers, (not shown in photo's) to the back side of my bracket to prevent pull through the the 8- 1/4" bolts. With the RV-10 operational G limit of 3.8, I considered this to a satisfactory install for a non-aerobatic plane. So there's my logic, right out on the table.


Thanks,
Bob

Well, the sheet says it should exceed those limits, so you'll probably be fine. I'm just conservative about stuff like that, which is why I'm asking about the clearance, even though I think that should be fine, too.