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Cake day: June 11th, 2023

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  • Rivalarrival@lemmy.todaytoxkcd@lemmy.worldxkcd #3124: Grounded
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    7 days ago

    The oxygen requirements only come into play when you fly depressurized.

    That is true for the 12,500, 14,000, and 15,000 feet cabin pressure numbers I gave, yes.

    However, the oxygen requirement associated with the 35,000 foot number I gave applies to both pressurized and unpressurized flight. If your aircraft is at or above 35,000 feet pressure altitude, at least one of the pilots must be on oxygen, or must have a quick-donning mask available at all times.


  • and the group I was hiking with started feeling it a little bit around 9000-10,000 ft.

    Hiking. Physical activity. You’ll feel it a lot sooner than if you’re just sitting in your seat, bored out of your skull.

    Legally, the FAA doesn’t require passengers to be on oxygen until cabin altitude is above 15,000 feet. Most aircraft are pressurized to the equivalent of 5000-7000 feet pressure altitude.


  • Rivalarrival@lemmy.todaytoxkcd@lemmy.worldxkcd #3124: Grounded
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    7 days ago

    just assume they were able to still oxygenate the cabin even if they couldn’t go as high

    Aircraft are typically pressurized to the equivalent of about 5000-7000 feet altitude.

    They do not oxygenate the cabin. The oxygen supplies on board are usually in the form of chemical generators, sometimes known as “oxygen candles”, and can only provide about 15 minutes supply. That should be plenty of time to descend below 10,000 feet, where everyone can come off oxygen. They don’t “burn” those chemical generators except in actual emergencies.

    Pilots and crew have a sufficient supply of bottled oxygen. Pilots and crew are required to go on oxygen if they spend more than 30 minutes above 12,500 feet cabin pressure, or any time over 14,000 feet. Passengers are required to be on supplemental oxygen above 15,000 feet cabin pressure.

    Above 35,000 feet flight altitude, at least one pilot must either be on oxygen, or have a mask that can be donned in less than 5 seconds.