Hello,

when setting the captain's and co-pilot's oxygen panels, it appears to me that as soon as the system is turned ON, the pilots are using it. This conclusion gathered from the fact that the flow bar rhythmically moves with the average adult breath cycle. In my experience this should be:

Supply OFF --> System is Dead
Supply ON, Demand Normal or 100%, Operating Mode Normal --> Pressure rises on the oxygen pressure gauge (No reference found for value, but 60-70 psi seems normal for indicator)
Supply ON, Demand Normal or 100%, Operating Mode Emergency --> Continuous flow bar as mixed or 100% positive oxygen flow commences. Should have a slight drop on regulator pressure
Supply ON, Demand Normal or 100%, Operating Mode Test --> Same as Emergency, but spring-loaded to Normal

As in idea, the flow bar can cycle as it does now, whenever the cabin altitude warning triggers. (To simulate the pilots doing their memory item of donning their masks) <-- Assuming the supply is ON and the Operating Mode is in Normal.

Hi, I can pass this along to the team. That being said I am not sure how the Oxygen system in the L1011 works, the reasoning from above is sound from what I can infer on this type of thing, if you have anything to add in the ways of source material then by all means. Thank you :)

This is from the TWA manual. We used these older systems on some MD80's I flew. It's all the same. The fact that the flow bar only appears when inhaling through the mask with the Supply ON is in this part of the manual. The TEST and EMERGENCY flow logically out of this.