Use of O2 for long flights above FL200

Bumblebee

Bumblebee

Commodore
Hello Dr. Forred,

First of all I would like to thank you again for spending your time here. We all appreciate that your time is valuable and that we are gifted by the fact you spend some here.

My question regards the following:

Historically, in unpressurized aircraft, we have used oxygen masks to fly at the flight levels on long reposition flights, such as nonstop to Alaska or Florida from California, with no safety issues reported. If someone were to need to use the facility (plastic bottle in the back of the aircraft), there was a portable O2 bottle for such a purpose.

If used properly and with training and caution, is there a basis in safety to discontinue the use of oxygen in favor of pressurization from an operational standpoint?

Thank you again, and I hope to see you at Network JC this year.

best,

Bumblebee
 
I think you may have misunderstood my question...I am not looking for a supplemental oxygen system.
My Flight Surgeon said:
I do not know. Look at Sporty's to see if they have one.
Click to expand...
If used properly and with training and caution, is there a basis in safety to discontinue the use of oxygen in favor of pressurization from an operational standpoint?
 
I am not sure what you are asking either.

I would think a pressurized cabin would always be preferable over being chained to a hose for the entire flight. The FARs state for us we if lose Cabin Pressure we have to land. Supplemental O2 can only be used to get you down to safe altitude prior to landing. The military of course will have different requirements.
 
It seems to me you are asking - Is a pressurized cabin better than supplemental O2. From both a safety and an operational standpoint, pressurization is better.
 
is there a basis in safety to discontinue the use of oxygen in favor of pressurization from an operational standpoint?

Here's why I ask. In most circumstances, air tankers fly below 12,500. Once in a while they need to reposition across country. Alaska or Florida from California, let's say. Some air tankers are not capable of pressurization, some are. Is there a reason to exclude the ones that aren't based on safety? Or is it just a preference? We feel it's an exclusionary requirement in the new RFP being drafted. I'm sure that using O2 can be done safely, otherwise there would be no turbocharged unpressurized aircraft at the Flight Levels. I was merely asking if there was any data to support a theory of a reduction in safety using O2 on a spider mask vs. a pressurized cabin.
 
Ahhhh gotcha now. Just my
.02 here. TMK When the mil does it the crews have a full fitted mask that is diluter demand type and can go full 02 under positive pressure if needed.

I don't know if the GA type masks /cannulas would be approved for large aircraft. Can you carry enough bottled oxygen? I think the mil uses liquid O2 to get the durations they need.

Damn good question.
 
we used to use plastic face masks...but I want to go spider with big tanks for x-c trips. with a portable for trips to the back. Heck they even used to use cannulas, but I think we can do better. Thanks for sticking with me on this, it actually has an important application.
 
No problem. I am definitely interested in the answer to this one.

Does Wright Patterson AFB still have their altitude chamber? They may be able to shed some light on this. This has to have been studied. If not it could be a project
 
The E-6B does have the full face smoke masks, but the flight deck also has the regular transport category aircraft quick don masks for pressurization problems.

One of the Navy requirements during loss of pressurization is to descend to 18,000 or lower. My assumption has always been that there are physiological effects for continued exposure to decreased pressure.
 
I am trying to determine, if there is a SAFETY reason to choose a pressurized tanker over an unpressurized tanker. For repositions only...


I could argue that if you know you're unpressurized, you won't be surprised by a de-pressurization event, so it's a safer way to go.
 
I used to fly old Convair's from LAS to SFO at FL240 on O2. Part 121 supplemental in the late 80's. The pressurization capability was "removed" as a cost factor. It was rare to fly long routes at high altitudes but they bid this route so there we were. I believe flying that route was the only time I wore O2 while working there (1.5 years). They "removed" the toilets, as well, but we had a nifty relief tube. Anyhow, it was no big deal wearing 02 masks for a couple of hours. I felt like a B-24 pilot heading for Polesti...
 
thanks... we feel this is more an exclusionary part of the new contract, rather than based in actual safety data.
 
It is possible that as you climb, Nitrogen bubbles in your blood come out of suspension as the pressure decreases. If that happens it can be pretty nasty business, having pressurization goes a long way to preventing such a situation occur. That being said, if you spend time breathing 100% oxygen before the flight, or even during the climb, it also goes a long way to negating the risk.
 
You must log in or register to reply here.
Back
Top