4 ms·

I don't think the other answers are getting at the meat of it. Consider that those red lights functioning is the only thing keeping hundreds or thousands of peo

I don't think the other answers are getting at the meat of it. Consider that those red lights functioning is the only thing keeping hundreds or thousands of people from getting killed. What sorts of safety and durability requirements would you impose on them? What sorts of maintenance and training requirements? If nothing else they need to hold up in every weather and temperature big airports exist (-80ºF to +150ºF) and get run over by airplanes all day. Already that's a non-trivial problem.

sokoloff 4y ago
These lights would not be the only thing keeping hundreds from being killed. ATC clearances over the radio are the primary thing; this is a secondary system.
- BoorishBears 4y ago
  That's an example of why they're expensive: they need to be engineered as if one day they might be. And no one chooses when or where that is
  - tempestn 4y ago
    That doesn't seem logical if the alternative is not having the lights at all.
    - CoastalCoder 4y ago
      > That doesn't seem logical if the alternative is not having the lights at all. If the norm becomes (radio clearance and no red lights), I suspect pilots will become conditioned to equate no-red-lights with landing clearance. Not 100%, but maybe at least 1% of the time. So if that happens and the red lights stopped working, you have a problem that wouldn't have existed if the red lights were never introduced. Perhaps a more resilient system would use green lights to indicate landing clearance. Then if the lights failed, the default would be radioing ATC for guidance? (I have no qualifications on this topic. I'm just guessing based on a bunch of Mentour videos I've watched.)
      - sokoloff 4y ago
        These will always only be at a minority of airports and probably always be at a minority of airports with airline service.
      - tempestn 4y ago
        That's a good point; if pilots come to expect the lights, I can see how it could be dangerous for them to fail, even if they're not supposed to be the primary mechanism.
      - jonahx 4y ago
        Exactly. The lights create a kind of moral hazard: https://en.wikipedia.org/wiki/Moral_hazard https://en.wikipedia.org/wiki/Moral_hazard
        Cpoll 4y ago
        I think https://en.wikipedia.org/wiki/Risk_compensation https://en.wikipedia.org/wiki/Risk_compensation might be a better fit.
        jonahx 4y ago
        Good point, thanks.
      - paledot 4y ago
        But my understanding is that the plane was taxiing. At this point, the problem isn't just the lack of red lights: the pilot took a wrong turn. There are reasons other than the possibility of crossing an active runway why you follow directions, among them that you want to end up at your destination.
    - nkozyra 4y ago
      An unreliable system is often worse than a non-existent one.
curun1r 4y ago
The other major concern is running reliable power to the lights. That isn’t something that can happen above ground when crossing runways, so there’s going to be at least some digging up the runway and repaving. Repaving runways isn’t cheap. It has to be done in an expedited manner since airports need all runways available during peak hours, so there’s usually a six-ish hour overnight window for work to get done and the runway left usable for the next day. This isn’t like normal roadwork where temporary metal plates can cover over unfinished work, so work must be done and the asphalt set during that window. This can mean large work crews doing highly-choreographed work that they’ve prepared (and even practiced) long in advance. The costs add up quickly.
- defrost 4y ago
  > so there’s going to be at least some digging up the runway and repaving. The US doesn't have horizontal directional drilling rigs that go under a runway and pull cable?
  - dredmorbius 4y ago
    Oil and gas rigs typically don't have to worry about intersecting other infrastructure. Even then, things occasionally go awry. <https://en.wikipedia.org/wiki/Lake_Peigneur#Drilling_disaster https://en.wikipedia.org/wiki/Lake_Peigneur#Drilling_disaste...> For an airport, the precision required both to not hit extant underground infrastructure and to know precisely where your newly deployed infrastructure is (for the next guy/gal to worry about) is probably a salient concern. I'm not sure that horizontal drilling offers that degree of precision and assurance as opposed to rip-and-dig methods.
    - defrost 4y ago
      If you're not sure then you might like to forget about oil and gas drilling and look to suburban optic fibre cable laying in which a cable can be accurately laid following a curving S path about the countours of a curving road avoiding other known pipes over distances of 500+ m.
deleted 4y ago
[deleted]

sokoloff 4y ago

These lights would not be the only thing keeping hundreds from being killed. ATC clearances over the radio are the primary thing; this is a secondary system.

BoorishBears 4y ago
That's an example of why they're expensive: they need to be engineered as if one day they might be. And no one chooses when or where that is
- tempestn 4y ago
  That doesn't seem logical if the alternative is not having the lights at all.
  - CoastalCoder 4y ago
    > That doesn't seem logical if the alternative is not having the lights at all. If the norm becomes (radio clearance and no red lights), I suspect pilots will become conditioned to equate no-red-lights with landing clearance. Not 100%, but maybe at least 1% of the time. So if that happens and the red lights stopped working, you have a problem that wouldn't have existed if the red lights were never introduced. Perhaps a more resilient system would use green lights to indicate landing clearance. Then if the lights failed, the default would be radioing ATC for guidance? (I have no qualifications on this topic. I'm just guessing based on a bunch of Mentour videos I've watched.)
    - sokoloff 4y ago
      These will always only be at a minority of airports and probably always be at a minority of airports with airline service.
    - tempestn 4y ago
      That's a good point; if pilots come to expect the lights, I can see how it could be dangerous for them to fail, even if they're not supposed to be the primary mechanism.
    - jonahx 4y ago
      Exactly. The lights create a kind of moral hazard: https://en.wikipedia.org/wiki/Moral_hazard https://en.wikipedia.org/wiki/Moral_hazard
      - Cpoll 4y ago
        I think https://en.wikipedia.org/wiki/Risk_compensation https://en.wikipedia.org/wiki/Risk_compensation might be a better fit.
        jonahx 4y ago
        Good point, thanks.
    - paledot 4y ago
      But my understanding is that the plane was taxiing. At this point, the problem isn't just the lack of red lights: the pilot took a wrong turn. There are reasons other than the possibility of crossing an active runway why you follow directions, among them that you want to end up at your destination.
  - nkozyra 4y ago
    An unreliable system is often worse than a non-existent one.

curun1r 4y ago

The other major concern is running reliable power to the lights. That isn’t something that can happen above ground when crossing runways, so there’s going to be at least some digging up the runway and repaving. Repaving runways isn’t cheap. It has to be done in an expedited manner since airports need all runways available during peak hours, so there’s usually a six-ish hour overnight window for work to get done and the runway left usable for the next day. This isn’t like normal roadwork where temporary metal plates can cover over unfinished work, so work must be done and the asphalt set during that window. This can mean large work crews doing highly-choreographed work that they’ve prepared (and even practiced) long in advance. The costs add up quickly.

defrost 4y ago
> so there’s going to be at least some digging up the runway and repaving. The US doesn't have horizontal directional drilling rigs that go under a runway and pull cable?
- dredmorbius 4y ago
  Oil and gas rigs typically don't have to worry about intersecting other infrastructure. Even then, things occasionally go awry. <https://en.wikipedia.org/wiki/Lake_Peigneur#Drilling_disaster https://en.wikipedia.org/wiki/Lake_Peigneur#Drilling_disaste...> For an airport, the precision required both to not hit extant underground infrastructure and to know precisely where your newly deployed infrastructure is (for the next guy/gal to worry about) is probably a salient concern. I'm not sure that horizontal drilling offers that degree of precision and assurance as opposed to rip-and-dig methods.
  - defrost 4y ago
    If you're not sure then you might like to forget about oil and gas drilling and look to suburban optic fibre cable laying in which a cable can be accurately laid following a curving S path about the countours of a curving road avoiding other known pipes over distances of 500+ m.

deleted 4y ago

[deleted]