Why are the lights expensive?
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.
The costs add up quickly.
The US doesn't have horizontal directional drilling rigs that go under a runway and pull cable?
Even then, things occasionally go awry.
<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.
Any references / sources on that?
As opposed to the alternative described, where you close down the runway, dig out a full trench, lay a cable in a conduit, and attempt to compact every thing back to how it used to be?
You think that's a better alternative than just drill core'ing the conduit through?
Interesting.
787 wingspan is 200ft (60m). Planes don't turn on a dime either, but the larger ones do have steering linked to the rear wheels, so their turn radius can be surprising.
The non invasive solution would be to require some kind of ground control computer link that can directly draw their controlled path for them on their displays and give them a nice loud master caution or warning if they're about to break their assignment.
Then we can start thinking about ground autopilot systems.
Back in the days of the Exxon Valdez tanker incident, I wondered if the technology did not exist to positively track such major asset positions/directions, and dispatch an alarm from one or more authorities at a distance.
In terms of powering lights/signals, perhaps solar, batteries and a generator for each patch, and if there is no flashing of light visible (indicating power-loss or stuck-at failure), tower clearance must be given?
The lights don't need to be tall enough that the wings would be able to hit them.
And no one chooses when or where that is
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.)
To put it into some relatable context, a simple electrical switch that you might grab for a few bucks at your local Home Depot would cost at least several hundreds of dollars because of all the red tape that must be satisfied for safety reasons.
Safety isn't cheap.
> because of all the red tape that must be
to
because of all the rigoy testing and precise engineering that has to be
Nobody is saying you can't pour theoretically meaningful pork into a traffic light in the form of QA and whatnot and get an indestructible traffic light that operates for a century without being touched in return. People are questioning whether that's actually necessary for a system that's already the Nth layer of redundancy.
All those inspections, certifications, and other requirements exist for very good reasons. Reasons that more likely than not cost us blood and tears to realize their need.
Nobody's debating that those processes work. People are questioning whether or to what degree this system should be subject to them. Just because something touches aviation somehow is not a blank ticket to pour red tape at it to satisfy some ideological lust for the "perfectly safe" system. For example, the facility lighting around an airport is just normal lighting used on any other large commercial facility, off the shelf sodium bulbs, LEDs, halogens in off the shelf fixtures, the kind of stuff you buy from all myriad of online supply houses and local suppliers. The runway lights are subject to much more specific requirements (but still very relaxed compared to the lighting on actual aircraft). Where do the traffic lights fall on that spectrum? IDK, but seeing as the system is never gonna leave the ground I'm pretty inclined to ignore whatever the people who think it needs to be designed like an aircraft have to say.
> Reasons that more likely than not cost us blood and tears to realize their need.
If/when they mandate a traffic light system at JFK will that rule be "written in blood" as you people often like to say?
Maybe it's worth having a worse system that actually is there.
When I was an intern I got to help change the blinking red light on top of a 50 story building. It’s a big deal that was scheduled weeks in advance and probably involved two dozen people, a special lightbulb and a bunch of coordination.
Even among the team working it plenty of “how many X does it take to change a light bulb” jokes were told.
But consider than a pilot depends on certain things being there when things go wrong. If the weather is bad and there’s issues with instruments, seeing that red light is the difference between life and death. There are potentially dozens or hundreds of people on a plane and if I recall correctly up to 4,000 people in the building.
When life is at risk, the standard for engineering must be higher.
How did you prove that?
If its more often, does an outage need to be detected? How do you detect that lightbulb went out?
How much does that cost?
Doesn't matter; that's not a comparison that's relevant to any decision here.
How many additional crashes per year are prevented by the high-cost bulbs, and how many additional dollars per year does it cost to install them on every building?
Maybe the 10 $10 light bulbs need to be replaced once a year and they cost $150 / year. Maybe the one $10,000 bulb needs to be replaced every 15 years and costs $900 / year. Once you've gotten to that point, at least you know what the cost difference is.
Then you can either ask "how many planes would crash into the Chrysler building every year if it was using 10 bulbs from Home Depot, compared to the one bulb it's currently using?", and compare that to $750. In that case you'd get an answer that told you whether the Chrysler building should use a special bulb. Or you could ask "how many planes would crash into buildings anywhere in the world every year if they all used 10 bulbs from Home Depot instead of what they currently use?", compare that to $750 multiplied by the number of tall buildings in the world, and you'd get an answer that would tell you whether it'd be better for every building in the world to use commodity bulbs or for all of them to use the bespoke bulbs.
But you'd never ask "which costs more, one fancy lightbulb or one crashing plane?". That won't tell you anything.
If/when it happens the professionals who deal in this stuff will say something mundane like "this system prevented ten close calls before we actually had one slip through, that's pretty great". And they'll replace the $5 lightbulb and move the "check the bulbs" from the monthly maintenance checklist to the weekly checklist. And you'll complain much like you're complaining now.
The irony is that the reason the safety numbers are that good is because aerospace is one of the only 5+ sigma quality/safety industries.
The fact that the absolute numbers are low does not change any calculations that follow from that ratio.
If your point is that close calls will always outnumber the actual accidents, that’s like saying the number of doctor visits will outnumber the number of cancer diagnoses. Safety incidents are always a subset of a larger set that also contains close calls. By their nature, most safety incidents require multiple things to go wrong, which means there will be more times that some, but not all, things will go wrong to create a close call. It’s almost such a trivial point that it’s hardly salient enough to mention.
So you decide, scre the airplane, a will save my life, and jump out. Only it fails to open, it was an unreliable parachite, bought by someone like you. They thought,'better a 50/50 parachite then no parachute?
So now you are plummeting to you death, thinking, that if you did not have the confidence of 'I have a parachute' you woupd have never attemped the barrel roll in the first place. And you would have done your utmost to steady the plane, and probably would succeed. And you would not waste time packing it and fuel carrying it around with you.
Your entire hypothetical is unlike the actual scenario, where this is being recommended.
Of course you have different solutions to a completely different problem — but what you haven’t addressed is why this is a bad solution to this particular problem.
The presence of a backup option affects your decision making. Human brain assumes the backup is reliable. If you install some 50/50 backup, you put more people at risk
Why is imagining something completely different useful?
If there's a safety mechanism that may or may not work, coming to rely on it is suicidal.
If there is no safety mechanism in the first place, you (hopefully!) never become complacent in the first place.
So it's better to either have a safety mechanism that will absolutely work every single time or nothing at all, than one that may or may not work and invite complacency.
You could do it a lot cheaper if you could accept them not working correctly sometimes. Like occasionally all the lights at an intersection would be green or something.