Canula Mask

[IP076]

Just wondering if anyone has a solid reference on the maximum altitude use for a Canula mask?


Jeppesen says the FAA restricts it to FL180, but doesnt give reference to an FAA Document.

Anyone got a good reference? Advisory Circular maybe?

 

[propilot]

Can't give you a reference, but when I was flying Chieftains in Alaska we'd climb to FL220 and had that restriction. We wore a canula up to FL180 and then were required to switch to a mask until we were below again. It was for sight seeing over and around Mt Mckinley...

 

[Lead Sled]

Just wondering if anyone has a solid reference on the maximum altitude use for a Canula mask?

I know of no Federal document per se that limits the use of canulas to 18,000' (Maybe Jafi can chime in here.) however, the documentation that comes with the canulas themselves give the limitations of the particular canula's approval.

It wouldn't be a smart move to tempt fate by going any higher than 18,000' with them - the risks associated with high altitude flight really start to compound as you climb above that altitude. Go spend a session or two in an altitude chamber and you'll find out what I'm talking about.

The problem with canulas is that it's pretty difficult to maintain adequate blood saturation levels much above 18,000' to 20,000' and one of the incidious characteristics of hypoxia is a feeling of well being. You can see where this is leading...

'Sled

 

[IP076]

Hey guys, thanks for the replies.

Basically it just came up in a conversation amongst some instructors, and the only reference we could find was the Jepp Commercial Text, which doesnt give an FAA reference.

Yeah, done the Altitude Chamber thing before. Darn awesome experience, recommend it to every one of my students.

 

[avbug]

Cannuals have two drawbacks; they're an inefficient delivery system as they're not closed nor sealed, and they can only deliver a very small oxygen flow rate. 6 liters per minute, vs. 15 for a mask.

The problem at altitude isn't so much the volume of oxygen as the partial pressure thereof, and the cannula does nothing to answer pressure problems. Only to make oxygen available. If you can't get the pressure, simply having it in the environment does little to get it into your lungs, to to permit adequate respiration.

I don't know of any specific altitude limitations for a cannuala, but you really should look to a mask instead.