The Pneumatic / Environmental System Mystery

Hello. I think I saw one thread that brushed on this topic, but I cannot find it again now, so I will start a specific Pneumatic / Environmental thread, with your pardon.

:helpsmilie:Has anyone got the low-down on the pneumatic system?

The Emergency Landing Gear and Emergency Flap extension valves are pretty straightforward. But I am dubious about the usage of the Emergency System Filling Valve (the bronze looking knob up near the canopy sill, right side), and the Air Net Valve and Cockpit Filling Valve, at the right of the screenie, have me completely stumped. Because the label names do not match up with the image of the pneumatic system near the bottom of this page, it is extremely difficult to figure out what is doing what and which is which.

Regarding the Emergency System Filling Valve. Well, one of those AI hints appears, asking you to open this valve, after you land if during the flight you got some damage that requires you to use the Emergency Landing Gear Extension. I am assuming, therefore, that opening this valve is necessary for the wheel brakes operation when operating on redundancy systems, as it seemed to me that the brakes did not operate until I had opened this valve. I don't know, it only happened once, so far, but that's what it looked like. Any ideas? Anything concrete?

Now, the Air Net Valve. What is an Air Net? Which is it on the diagram? I cannot begin to guess...

Finally, the Cockpit Filling Valve. Again, I am having to assume, and I do not like doing so. I start here. The Cockpit Air Valve, the tap down on the right side floor with the ambient controls, is a double feature unit, according to the description;

Ie; Cockpit air supply valve (from the environmental control system) and slide valve (from the pneumatic system) in a common casing

It leads me into thinking that in the first instance it is able to use the engine bleed air for pressurization (normal) and in the second instance, it can use the pneumatic system for pressurization (abnormal). However, does this mean that if there is a bleed air failure and I want to use the pneumatic system for pressurizing the cockpit, would I have to open the Cockpit Filling Valve? I have tried in flights to simulate this, but of course as the bleed system is operating and I have never had the bleed system damaged or failed, results are inconclusive because the tap primarily controls the (not failed) bleed air. So again, I don't know.

I hope someone can clarify this issue, please. I have attempted to translate parts of the Russian manual with Google translate to get to the bottom of this, but it seems pretty sparse on information regarding, itself.

Thank you in advance!

I've also had the in-game advice tell me to open this valve twice. On both occasions, I was landing after being damaged and was attempting to apply brakes. Since then, like you, I've been working on the assumption it is for refilling the pneumatic reservoir for brakes etc rather than for envorinmental / cockpit reasons. I would also be interested to know the function of air net valve.

All I can say is that you can climb to 10k Angels and still breath with no cockpit glass for more than 10min. Afaik this should not be.

Wasnt ot mentioned/fixed before that you faint away above 3k when no Oxygen supply and pressure is set ?

Bit

Mt. Rainier in Washington State, USA, is just a bit below 15,000 feet. People hike up without using oxygen tanks. I think they acclimatize at Camp Muir a day or two before a summit attempt.

All I can say is that you can climb to 10k Angels and still breath with no cockpit glass for more than 10min. Afaik this should not be.

 

Wasnt ot mentioned/fixed before that you faint away above 3k when no Oxygen supply and pressure is set ?

 

Bit

I think you have your units mixed up. "10k Angels" would be 10000000 or ten million feet, way beyond what any aircraft is capable of. 10k feet or angels 10 would be perfectly safe for most people. People settle at altitudes higher than that (link). 10k meters on the other hand would kill you quickly.

I've hiked to 11,000 feet and it is not pleasurable at all. Needed to go to 11,500, but it was a no go. (Colorado ski resort- looking for Ptarmigan)

I think you have your units mixed up. "10k Angels" would be 10000000 or ten million feet, way beyond what any aircraft is capable of. 10k feet or angels 10 would be perfectly safe for most people. People settle at altitudes higher than that (link). 10k meters on the other hand would kill you quickly.

Mt. Rainier in Washington State, USA, is just a bit below 15,000 feet. People hike up without using oxygen tanks. I think they acclimatize at Camp Muir a day or two before a summit attempt.

Yeah, I am pretty sure it is a confusion of units, too. Up to 10,000 ft is nothing for most people, especially if they acclimatize and get a few more red blood cells going around at a slightly lower altitude first. I currently live at 8,350 ft amsl, and have been up mountains up to 16,480 ft, without oxygen and with considerable physical exertion, when I was in my early thirties. I would not like to try it again now, though, several years on...:smilewink:

It varies per person, but an individual can quite easily survive with 100% on demand oxygen up to about 30,000 ft, with positive pressure 100% oxygen up to about 40,000 ft, and above that they will in addition generally need a pressurized cabin or pressure suit, to allow the relative blood pressure to be high enough to permit the proper osmosis of CO2 / O2 in the alveoli to occur, else you suffocate internally, even on oxygen. These are rough figures, I say again, and will vary with different people.

Back on topic;

I had one opportunity to try that Cockpit Filling Valve under the terms of my conjecture in the first post, but am still at a loss as to what it does, really. I got some damage that disabled in some way normal pressurization; that is, there was no differential pressure on the cabin altimeter instrument, and cabin altitude was equal to indicated altitude. Thought me; "Aha! Time to use the Cockpit Filling Valve".

Turned it. Nothing.

Now, I may have done it wrong and wasted the pneumatic charge by not doing something else necessary first? Or after? Or the the integrity of the cabin was already compromised by a bullet hole and could not be pressurized? I don't know, but I am still lost as to its function...