[ajross]

> For those thinking about preventative solutions, there are some existing, all very expensive of course. The simplest is placing a row of red lights in the ground at all intersections to runways.

That's... a street light.[1] When street lights become "very expensive of course" it's time to revisit our priors about how we regulate. And I say this as someone not normally inclined to libertarian rhetoric.

[1] To be clear: a proven and effective technology deployed successfully literally millions of times over the past century of traffic control!

[jamiek88]

It’s not a street light.

You aren’t going to have poles or hanging lights on a runway.

It is embedded lights.

That have to work without fail in extreme temps, all weathers, with planes rolling over them all day.

They have to have certain visibility at different angles, they have to fail gracefully.

These things are rarely ‘that’s just…’

[mopsi]

You make it sound much more difficult problem than it actually is. Embedded lights are nothing new, every small to medium airport has hundreds of them, larger airports thousands - marking runway and taxiway centerlines. Technical characteristics, installation requirements etc have been standardized a long time ago by the International Civil Aviation Organization and it's paint-by-the-numbers now. Such lights are literally off-the-shelf products and every airport maintenance team already knows how to install and take care of them.

Honeywell et al all have huge catalogues with all kinds of aerodrome lights. Here's Hughey & Phillips: https://www.hugheyandphillips.com/wp-content/uploads/2022/06...

As you can see, embedded lights are also represented from pg 23 onwards and red "stop bar" lights can be found on pg 38. Here's a picture of them installed: https://i.imgur.com/ThNIQaw.jpg

[doubleunplussed]

They're a backup system if the currently in-use systems fail. If they work only 99% of the time, they've cut accidents in the class they are designed to prevent by 99%. That's excellent. Perfection does not seem any more necessary here than in other contexts, and seems like the enemy of the good.

This compliant seems to me akin to me not backing up my computer's internal drive to this external drive I have sitting on my desk, until I can make a little RAIDed setup to address the small probability that the backup drive will fail. Having no backup at all is worse than requiring a high standard to the point that the backup may not be implemented.

It's not like if they break, nobody will notice. Install them, have a process to verify they're working regularly, fix them if they break. Any downtime whilst they're being fixed is just as risky as every day the project is delayed to to this high standard of reliability.

[cguess]

When it comes to airplanes 99% is never enough. It's why after every accident (or this near accident) there are months if not years of inquiries and analysis of every second leading up the incident going back days or weeks or even months. It's why flying is the safest way to travel by a huge margin.

If even one indecent like this happens hundreds of people die in a horrible all consuming fire, travel for the entire seaboard would be halted, hundreds of thousands of passenger would be dealt with for not being where they are supposed to be, and that's before the extraordinarily expensive repair to the tarmac and the scrapping of the planes. There is, quite literally, zero margin of error.

[exmadscientist]

> 99% is never enough

99% is absolutely reasonable for one layer of defense among many! That is one of the best methods to achieve truly high reliability, as is needed in this case: stack many reliable systems in such a way that they all must fail to get an overall failure. It is not perfect, of course, and things can always cascade, but it is a powerful technique.

[cguess]

I'm guessing you've never worked in system-critical infrastructure? Airplanes are another level up from that. I'm not the one saying this, the FAA and NTSB are. Nothing is allowed to go wrong, ever.

[astrange]

I've been stuck at SFO for hours at least once a year because our flight had some mechanical issue. (Always on a Delta flight to ATL or MSP, don't know why.)

They did fix it and then eventually we took off. In a way that's "not going wrong". On the other hand, they didn't cancel it and send the plane to be disassembled for failure analysis. That'd certainly be safer.

[zmgsabst]

Right.

So it’s very strange you’re passionately arguing to keep the riskier current setup that almost had a massive accident — rather than improve it.

Perfect is the enemy of better.

[ajross]

Runway lighting is 80 year old technology; we solved all those problems long, long ago. I mean, come on. It's one thing to point out that problems are inherently complicated, but to pretend that we can't deploy something as obvious as, yes, a street light because of expense is making yourself part of the problem, not the solution.

[ClumsyPilot]

> lighting is 80 year old technology

The first gas turbine was invented in 1791

Are they cheap? Can you buy them for next day delivery?

[mopsi]

> Are they cheap? Can you buy them for next day delivery?

Yes. They are consumables comparable to bulbs and light fixtures at home, just good LEDs on a PCB in a metal/plastic case. It's sheer insanity to pretent that aerodrome lights are some magic technology.

[astrange]

Are there actually different more expensive lighting technologies for this? Or do you just get more lights so there's more redundancy?

Seems like most of those problems would be more caused by the power cables than the light itself.

[kube-system]

The vast majority of road intersections do not have traffic lights. This is because they are expensive. People die every day at intersections without traffic lights. The money to put up the lights just doesn’t exist. A basic 4 way stop is about a quarter million to put in traffic lights. And even at that price you do not get lights with high availability features.

[landemva]

This speaks to the need to implement systems with inherent safety. Traffic circles for cars.

I don't know what the corresponding term would be for taxiways, though I expect the reply here will be spelled 'not practical'.

[kube-system]

If you limited a design to traffic circles for taxiways, it wouldn’t be possible to cross any runways. Because planes can’t go around turns in the middle of their takeoff or landing. But if you wanted to prohibit any crossing of runways you could also just not have taxiways mid-runway. Probably not the most practical solution.

[thombat]

It would certainly be rate-limiting if every landing plane had to roll to the very end of the runway before turning off on "the taxiway". In principle this could be reduced by having planes with shorter rollouts leave the glideslope and continue level for some predetermined distance before touching down but that's got a bunch of new hazards even without adding any interesting wind.

[dmurray]

Yes, it's impractical to have a roundabout in the middle of a runway which an airliner must negotiate during its takeoff roll.

[thombat]

Given how the passengers squeak with moderate turbulence, imagine how they'll take high-speed veering during takeoff? But of course a roundabout only works because all vehicles approaching are preparing to come to a complete stop if another vehicle will intrude upon their path, which can never be compatible with "accelerate steadily to racing car speed"