[ehnto]

Pilots would have to blow 0.0 but that doesn't mean zero evidence of alcohol. In 4 hours you can metabolise around 4 standard drinks out of your bloodstream. It's not like drugs where any trace is bad because it's illegal.

That said, I'm not sure I am on board with the explanation. It could just be that with everything going on in a cockpit it wasn't noticed.

[Scoundreller]

Does reduced air pressure speed up the removal of alcohol via breathing?

If a fever can, wouldn’t alcohol do the same?

[bcOpus]

A fever is, at it’s core, an increase in metabolic rate. Your hypothalamus is telling your body that it’s temperature set point is higher than usual, and it takes energy to raise your temperature. I don’t see how a difference in air pressure would have a similar effect.

[mediawatcher234]

other way around - reduced air pressure is reduced oxygen, which is lower metabolism. Higher metabolism causes EtOH degradation to go more quickly. Fever is higher metabolism.

[Scoundreller]

Your blood oxygenation will stay at 95-99% even while in a cabin.

Metabolism in aircraft is pretty low: you’re generally sitting idle, but I think the alcohol metabolism is still constant except the terminal metabolism.

Fever is partly metabolism, but largely reduced cooling.

[agurk]

I've taken an oximeter with me on flights before, and can give a data point of n=1 to say this isn't the case.

My oxygen % decreased initially with altitude until it stabilised around 90-92% (at ~10k feet, IIRC). It sat at this point for the whole flight (8 hours), with a low of 87%.

Through forced rapid deep breaths I could get it back up into the mid-high 90s, but also got light headed and funny looks.

Moving around the cabin would also raise it.

[Scoundreller]

Interesting, the studies i’ve Read pegged the average reduction at 4%.