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Passengers still get trapped for hours on airplanes sitting on tarmacs. I feel like there's a couple of stories about that per year, and that's just what gets r

Passengers still get trapped for hours on airplanes sitting on tarmacs. I feel like there's a couple of stories about that per year, and that's just what gets reported in the media.

lisper 9y ago
No, they don't, not any more. https://www.nolo.com/legal-encyclopedia/tarmac-delays-airline-passenger-rights-33011.html https://www.nolo.com/legal-encyclopedia/tarmac-delays-airlin... Even back in the day when it did happen, it was because of policy, not physical constraints.
- ricardobeat 9y ago
  Three, or two, hours still counts as 'trapped for hours'. Airplanes are not comfortable at all, and no hyperloop pods actually exist - that statement makes no sense.
  - lisper 9y ago
    Except that airplanes are designed to be occupied for hours. In particular, airplanes have bathrooms.
    - eridius 9y ago
      AIUI airplanes just sitting on the tarmac don't have AC (because they're not running their engines).
      - lisper 9y ago
        AIUI? (But this is another good point: a failed hyperloop also won't have A/C. That will be a potentially life-threatening problem in Dubai, where the first hyperloop is likely to be built. Summer temperatures there regularly reach 45C.)
        eridius 9y ago
        AIUI means As I Understand It. Why can't a failed hyperloop have A/C?
        lisper 9y ago
        Ah. So first, commercial aircraft typically start their engines immediately upon leaving the gate. An extended period of time without A/C is extremely rare, and nowadays regulations require A/C for any tarmac delay over an hour. Second, the reason you can't have A/C in a failed hyperloop is that there's nowhere to discharge the heat. As long as the pods are moving you can discharge heat into the tube (because it's not a hard vacuum) but as soon as they stop you can't do that any more.
        eridius 9y ago
        Discharging heat is a good point. I imagine you could probably design the pods such that if they break down, they could extend radiators to contact the hyperloop wall in order to discharge heat that way. Though actually this raises another question in my mind. How do spacecraft handle heat? Or is the problem with spacecraft keeping them warm enough, rather than dealing with excess heat?
        lisper 9y ago
        Spacecraft use radiators to radiate excess heat into space. Depending on how close they are to the sun they can have both heating and cooling problems simultaneously. The side facing the sun can get too hot and the side away from the sun can get too cold. Thermal management of spacecraft is an engineering discipline unto itself. (I used to work for NASA.) Radiating heat to the tube won't work because the tube is either above ground, in which case it's likely to be much hotter than ambient if the sun is up, or underground, in which case you've effectively wrapped the tube in a nice insulating blanket of dirt, and again there is no place for the heat to go.
        eridius 9y ago

Passengers still get trapped for hours on airplanes sitting on tarmacs. I feel like there's a couple of stories about that per year, and that's just what gets reported in the media.

lisper 9y ago

No, they don't, not any more. https://www.nolo.com/legal-encyclopedia/tarmac-delays-airline-passenger-rights-33011.html https://www.nolo.com/legal-encyclopedia/tarmac-delays-airlin... Even back in the day when it did happen, it was because of policy, not physical constraints.

ricardobeat 9y ago
Three, or two, hours still counts as 'trapped for hours'. Airplanes are not comfortable at all, and no hyperloop pods actually exist - that statement makes no sense.
- lisper 9y ago
  Except that airplanes are designed to be occupied for hours. In particular, airplanes have bathrooms.
  - eridius 9y ago
    AIUI airplanes just sitting on the tarmac don't have AC (because they're not running their engines).
    - lisper 9y ago
      AIUI? (But this is another good point: a failed hyperloop also won't have A/C. That will be a potentially life-threatening problem in Dubai, where the first hyperloop is likely to be built. Summer temperatures there regularly reach 45C.)
      - eridius 9y ago
        AIUI means As I Understand It. Why can't a failed hyperloop have A/C?
        lisper 9y ago
        Ah. So first, commercial aircraft typically start their engines immediately upon leaving the gate. An extended period of time without A/C is extremely rare, and nowadays regulations require A/C for any tarmac delay over an hour. Second, the reason you can't have A/C in a failed hyperloop is that there's nowhere to discharge the heat. As long as the pods are moving you can discharge heat into the tube (because it's not a hard vacuum) but as soon as they stop you can't do that any more.
        eridius 9y ago
        Discharging heat is a good point. I imagine you could probably design the pods such that if they break down, they could extend radiators to contact the hyperloop wall in order to discharge heat that way. Though actually this raises another question in my mind. How do spacecraft handle heat? Or is the problem with spacecraft keeping them warm enough, rather than dealing with excess heat?
        lisper 9y ago
        Spacecraft use radiators to radiate excess heat into space. Depending on how close they are to the sun they can have both heating and cooling problems simultaneously. The side facing the sun can get too hot and the side away from the sun can get too cold. Thermal management of spacecraft is an engineering discipline unto itself. (I used to work for NASA.) Radiating heat to the tube won't work because the tube is either above ground, in which case it's likely to be much hotter than ambient if the sun is up, or underground, in which case you've effectively wrapped the tube in a nice insulating blanket of dirt, and again there is no place for the heat to go.
        eridius 9y ago