FAR 61.31g -Pressurized aircraft section

[poadeleted20]

If that were true they have avenues to fix it. The simplest avenue would be for AFS-800 to got to the Region Attorney and have him write the GC and request a ruling. The other would be for them to submit a rule change through the proper channels.

Since they seem happy with the rule as written, why would they want a change? And since they seem to think it says what they want, why would they need an interpretation to support that?

In any event, the flea is in their ear. We'll see if they do anything about it. But the only way I see this becoming a significant issue is if someone at the FSDO level writes up a pilot for violating the rule, and I can't remember seeing a 61.31 additional training endorsement case ever reaching that level. My guess is they really don't care that much since the insurers pretty well keep it from becoming an enforcement problem.

 

[Jaybird180]

Since they seem happy with the rule as written, why would they want a change? And since they seem to think it says what they want, why would they need an interpretation to support that?

In any event, the flea is in their ear. We'll see if they do anything about it. But the only way I see this becoming a significant issue is if someone at the FSDO level writes up a pilot for violating the rule, and I can't remember seeing a 61.31 additional training endorsement case ever reaching that level. My guess is they really don't care that much since the insurers pretty well keep it from becoming an enforcement problem.

So the conversation you had was a back channel discussion?

 

[Alexb2000]

All this talk has me thinking of all the WWII aircraft flying around unpressurized on similar oxygen systems as we use today. For example the B-17's service ceiling was ~35K.

Now with pulse oximeters, etc. many of us are still worried about flying in the high teens.

 

[gismo]

All this talk has me thinking of all the WWII aircraft flying around unpressurized on similar oxygen systems as we use today. For example the B-17's service ceiling was ~35K.

Now with pulse oximeters, etc. many of us are still worried about flying in the high teens.

First, their O2 "systems" were quite a bit more complex than a single stage regulator feeding a cannula and second the bombers at least had multiple crew members watching out for each other. I don't know for certain but I assume that the crews had some altitude training as well.

 

[Alexb2000]

First, their O2 "systems" were quite a bit more complex than a single stage regulator feeding a cannula and second the bombers at least had multiple crew members watching out for each other. I don't know for certain but I assume that the crews had some altitude training as well.

Assuming one uses a face mask above 18, how are they different? I read this detailed piece and didn't see a material difference, maybe I missed it?

http://webs.lanset.com/aeolusaero/A...ilitary_Aviation_Oxygen_Breathing_Systems.pdf

Agreed about crew, but we often have crew and technology (oximeters) as well.

 

[gismo]

Assuming one uses a face mask above 18, how are they different? I read this detailed piece and didn't see a material difference, maybe I missed it?

In operational function, the new diluter-demand system used a suction actuated valve that opened on the initiation of the inspiratory cycle by the user. The mix-selector was usually left in the ‘on’ position, which automatically selected the correct oxygen/ambient air ratio required by the user up to about 30,000 feet. Thereafter it supplied 100% oxygen. With the mix-selector in the ‘off’ position, 100% oxygen was delivered at all times, no matter what the given altitude the user was at. Shortly after introduction, due to some confusion over specific meanings, these two selections were relabeled "Normal Oxygen" and "100% Oxygen". The automatic response of the diluter-demand system also accommodated the variable use needs of the user without further inputs from the wearer; it additionally featured an "Emergency" control that would bypass all of the circuitry and deliver a constant flow of 100% oxygen to the wearer, if selected, irregardless of altitude or respiratory needs.

As part of the new Diluter Demand oxygen breathing system, an entirely new breathing mask was required for aircrew use, since only a mask configured for response to discrete respiratory cycling would suffice (although as previously noted, the older A-8B type continuous flow mask could be retrofitted with valves and a hose that would allow it to be used as a ‘demand mask’). This new mask was quickly developed by the combined Aeromedical and Equipment research teams at Wright Field, in cooperation with commercial engineers. The development of this new mask was considerably aided through research done earlier, by various rubber companies in cooperation with the US Army’s research teams at Aberdeen and MIT, on the need to devise a new generation molded rubber facemask to protect soldiers against chemical warfare agents.

From the excerpt above alone I'd conclude the system used by B17 crews was a bit more complex than my Scott portable system or the 50 cent masks that come with a Bonanza built in O2 system. And having actually disassembled a demand/diluter regulator I've seen clear evidence of their complexity.

Agreed about crew, but we often have crew and technology (oximeters) as well.

Pulse oximeters are great (I fly with two) but the ones available for in-flight use don't monitor continuously and therefore will not warn in the case of delivery problem. And, yes when you have someone along they might pick up on your hypoxia although that's not a given if they're not pilots and/or unfamiliar with O2 use. Even if your non-pilot friend happened to notice that you were nodding off or slurring words would they know what to do about it?

 

[Alexb2000]

Lance-

All of the valve technology was to conserve oxygen based on what I read. Our system is the same as the earlier 100% systems, simple high to low pressure regulator. Granted not military quality, but you don't hear of a lot of failures either.

All I'm saying is that people climb Mt. Everest without O2 or even with O2 to 29k, while exerting great effort. 70 years ago thousands of aviators flew with similar systems into combat. We should be able to manage sitting on our butts into at least the high teens without a lot of drama in 2013.

 

[tonycondon]

take a look around the airport and note average age and physique of the pilots you see. Then compare to pictures of WWII air crew and Mt. Everest climbers.

 

[denverpilot]

take a look around the airport and note average age and physique of the pilots you see. Then compare to pictures of WWII air crew and Mt. Everest climbers.

You haven't seen who's sorry asses have been being dragged up Everest by Sherpas lately, too?

 

[tonycondon]

no i havent