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.
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.
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.
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.
Sure they do. But then you have a tunnel under the runway that will flood and potentially freeze. Crumbling concrete and nonflat surfaces is not something you want on a runway or taxiway.
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?
Why can't they have two huge, red, flashing lights at either side of the crossway, thus avoiding the costs to dig up runway asphalt altogether? Better than what they seemingly have now ...
There may be designs that cut out some/most of the cost, but I made the comment because I watched a YouTube documentary on an airport that was making modifications and they had to dig up a bunch of the runways. They made a big deal out of the work, including working with a special contractor who had a practice area where they tried all the work they'd have to do ahead of time and timed themselves to be sure they could get the runway back in operating condition by the time it was needed. The amount of work they went through for something fairly minor was pretty memorable. I took from it that airports have a lot of logistical concerns that are pretty unique and the "that seems simple" take that I'd previously had about the tarmac portion of an airport being just a bunch of asphalt with some signs and lights on it was totally ignorant of all the complexity.
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.
> and give them a nice loud master caution or warning if they're about to break their assignment.
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?
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.
> 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.)
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.
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.
Manufacturing certifications, installation and maintenance inspections and certifications, auditing, etc.
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.
Red tape isn't the phrase I'd use in this context since your point is that the switch will work 100% of the time even after being thru a literal hurricane, so the difference isn't merely the tape, but that there's been proper testing and engineering all the way down, which drives the cost way up.
Unfortunately, this is exactly how it's characterized in the aerospace industry. Often the requirements that are design to reduce/verify quality and safety requirements are talked about as "bureaucracy" and "just paperwork."
I admit my vocabulary is failing me at the moment in finding similarly concise words to describe it, but I'm happy if the meaning gets through one way or another.
Every strip of BS red adhesive has some flimsy pretext to justify it.
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.
I don't know how airport infrastructure requirements work, but for the actual airframes themselves, the requisite level of reliability/redundancy are strictly defined. I would imagine airport design is similar. If so, it's clear if it's necessary or not.
I realize reading this now that "red tape" was not the appropriate way to convey what I'm trying to convey. I'm going to try and figure out how to rephrase that better in the future.
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.
>All those inspections, certifications, and other requirements exist for very good reasons
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?
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.
There are already crews at every major airport that inspect and replace runway lights every day. Maintaining more lights doesn't seem like a massive new undertaking in the way you are describing.
Compared to the cost of an air incident, $9900 is a rounding error. You’d need an actuary to know for sure, but even small differences in safety margin can be worth the cost in aviation.
> Compared to the cost of an air incident, $9900 is a rounding error.
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 this system fails when needed, every cent spent on it will be considered a waste. Nobody is going to say "sure, 300 people died and a couple $150m planes were destroyed.. but we saved a couple million dollars when it was installed 7 years ago".
It would be ideologically convenient for you if people died but statistically it's just gonna be another close call since close calls outnumber accidents in this field by a ton to one.
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.
Obviously, but that's not the question I asked. Right now it's not there at all - so would it be worth installing a less reliable system, but then you could have it in more places?
Imagine you are doing barrel roll and struggling to control a plane, and you have a parachute.
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.
Why would you do a barrel roll in a plane full of passengers, when you’re being paid to operate it safely?
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.
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.
The lights are a critical system that must operate without failure or errors.
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.
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.