Change Oxygen Tank?

[c1tice]

Purchased a 1981 231 last fall, N40AP. I love it so far. I have been doing avionics upgrades, it was state of the art in 1981 but now the GTN 750Xi is great. (I have an RCA weather radar about to go on eBay, it worked until it was removed and would give pong a run for the visuals) Also glad to get rid of the vacuum pump after if failed, with 2 GI275's. I highly recommend getting rid of the vacuum pump as I witnessed a crash in 1986 because of a vacuum pump failure. Now getting around to the O2 tank.

My steel 02 tank was out of date so I ordered an new one. I mistakenly ordered a 115 cu ft steel O2 tank instead of the 76 cu ft steel one that was removed. My question is can I install the steel 115 cu ft tank? The Mooney Service Manual lists the 115 cu ft composite but not the steel. We can make the brackets work and I purchased bigger bands. The steel is 22 lbs heavier fully charged than the 76 cu ft. My mission this weekend is to verify how many if any ballast are in the tail. Does anyone have any experience with such a change. I called FSDO but they have not called ne back yet. Would a 337 take care of the upgrade? I don't know if it is even allowed. Left a message with Mooney too. $350 restocking fee plus shipping from NC to CA to get the same that was removed and solve this headache I have created. Any pilots have an opinion? (we all know that answer)

 

[N201MKTurbo]

14 minutes ago, c1tice said:

Purchased a 1981 231 last fall, N40AP. I love it so far. I have been doing avionics upgrades, it was state of the art in 1981 but now the GTN 750Xi is great. (I have an RCA weather radar about to go on eBay, it worked until it was removed and would give pong a run for the visuals) Also glad to get rid of the vacuum pump after if failed, with 2 GI275's. I highly recommend getting rid of the vacuum pump as I witnessed a crash in 1986 because of a vacuum pump failure. Now getting around to the O2 tank.

My steel 02 tank was out of date so I ordered an new one. I mistakenly ordered a 115 cu ft steel O2 tank instead of the 76 cu ft steel one that was removed. My question is can I install the steel 115 cu ft tank? The Mooney Service Manual lists the 115 cu ft composite but not the steel. We can make the brackets work and I purchased bigger bands. The steel is 22 lbs heavier fully charged than the 76 cu ft. My mission this weekend is to verify how many if any ballast are in the tail. Does anyone have any experience with such a change. I called FSDO but they have not called ne back yet. Would a 337 take care of the upgrade? I don't know if it is even allowed. Left a message with Mooney too. $350 restocking fee plus shipping from NC to CA to get the same that was removed and solve this headache I have created. Any pilots have an opinion? (we all know that answer)

 

What is the weight of the 115cu ft composite cylinder compared to the steel? That would be the biggest problem getting a field approval. You would need to convince the inspector that the structure can support it.

If it is more, you would probably need the opinion of a DER before they would approve it. That will cost more than $350

Edited February 26, 2021 by N201MKTurbo

[Guest]

I’ve got a 77 foot Kevlar cylinder mistakenly ordered when I need a 115.  I’d love to see it gone.

Clarence

[A64Pilot]

Any decent SCUBA shop should be able to give you the number of a local shop to hydro your steel tank, once hydro tested, a hydro is good for 5 years.

unfortunately I don’t believe kevlar tanks can be recertified, once they hit expiration date, they are no good.

In other words don’t buy new tanks every 5 years.

‘Cost of hydro ought to be about $50.

Edited February 27, 2021 by A64Pilot

[carusoam]

Welcome aboard c1 and A64...

For questions about O2 tanks...

This is a fun one....

Yesterday, somebody was looking for lead ballast weights... aka Charlie weights...

Today, somebody has too much weight in the tail... and may need to off load some Charlie weight...

Let’s see if we can introduce you two... ( @spistora are you around?)

The Mooney factory is alive and well... you can get help on these things from an official resource....

If you have a local MSC... they can be extremely helpful as well...

And Clarence above is also a great MS resource... you may want to consider what he has on hand...

In the end, you are going to want a mechanic that is really good with his WnB math....

Best regards,

-a-

[carusoam]

Note for the new guys...

It is genuinely challenging to give all the help you need... if you don’t include some form of location of where you are at...

If unable to list your home drome, consider listing a state or what part of a state you are in...

I know the internet can be a terrifying place... But this is MS... it’s on the internet, but it isn’t the internet...

Best regards,

-a-

[larryb]

I bought only Kevlar tanks had a life limit? Could the original steel tank just need a hydro inspection?

[Guest]

This may be helpful.  Some steel cylinders as well as composite cylinders do have a retirement life.

Clarence

[c1tice]

Good point Carusoam I did not realize my location was not listed, such a rookie/nub. I am in Greensboro, NC. I saw the post about needing weights. I will get back @spistora if I need to off load those weights. Charged weights for steel tanks with regulator ( according to the Scott document I attached if viewable) - 77 cu ft -30.15 lbs :  115 cu ft - 44.7 lbs 

I have to think getting a DER involved may be more than the cost to correct my mistake and that is a good suggestion N201MKTURBO, it is worth inquiring.

I did some W&B calculations and 14 lbs at station 125 adds 1750 to the moment and that moves the CG aft .9 according to my layman's calculations, which I thought was surprisingly little.  

Clarence and I are chatting.

Thanks for all the replies. This is a great Space.

Chris

 

AmbMIVp1.pdf

Edited February 27, 2021 by c1tice

[spistora]

Thanks @carusoam for helping connect the dots around here.

@c1ticelet me know if you do want to get rid of some of the weights.

Thanks.

Steve