Friday night’s near-disaster at JFK airport | Hacker News Reader

Friday night’s near-disaster at JFK airport

viewfromthewing.com

393 pointsbgc350 comments

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. When an airplane is cleared for takeoff and until it is airborne the controller presses a button and turns all these lights red. Pilots are instructed that regardless of clearance, a red light over-rides that, and to never cross it. These lights are installed at JFK, but apparently NOT at the intersection inquisition. (https://en.wikipedia.org/wiki/Runway_status_lights).

JFK also has Airport Surface Detection Equipment (ASDE). Which is essentially ground radar including transponder/ADS-B replies. Many have automated alerts when it detects a potential runway incursion. Not known if any such system alerted the controller.

There is obviously room for more to be done in this space.

Why are the lights expensive?

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.

Safety isn't cheap.

The extra cost for safety is reducing safety because it's causing this not to get installed.

Maybe it's worth having a worse system that actually is there.

Unreliable systems aren’t there when you need them.

Neither are nonexistent systems.

There is a psychological element to it.

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.

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.

nono, imagine you have a personal 1 seater plane

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

Right — that situation is completely unlike the actual one. Different situations reasonably have different constraints.

Why is imagining something completely different useful?

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.

>close calls outnumber accidents in this field by a ton to one

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.

All industries have close calls outnumbering real accidents by a ton.

The fact that the absolute numbers are low does not change any calculations that follow from that ratio.

Look at the history of aviation before it was a 5-sigma industry. The safety record was much worse.

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.

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?

Easy to preach, harder to practice.

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.

What would be better for safety? One $10000 light bulb, or ten $10 light bulbs?

The former, if the latter fails to satisfy some design constraint.

How much more/less often do those ten $10 light bulbs go out?

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?

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.

What’s better for safety? Predicable reliability or whatever the subcontractor is putting out in a particular day

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.

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.

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.

one way to phrase it might be to change

> because of all the red tape that must be

because of all the rigoy testing and precise engineering that has to be

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 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?

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.

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."

Just assume that whenever something involves a plane it costs at least an order of magnitude more :). Nothing on a runway is cheap.

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.

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'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

That doesn't seem logical if the alternative is not having the lights at all.

> 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.)

These will always only be at a minority of airports and probably always be at a minority of airports with airline service.

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.

Exactly. The lights create a kind of moral hazard: https://en.wikipedia.org/wiki/Moral_hazard

I think https://en.wikipedia.org/wiki/Risk_compensation might be a better fit.

Good point, thanks.

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.

An unreliable system is often worse than a non-existent one.

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.

> 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?

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_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.

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.

Thanks.

Any references / sources on that?

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.

Then you have an electrical cable in a conduit.

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.

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.

> flashing lights at either side of the crossway

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?

> 787 wingspan is 200ft

The lights don't need to be tall enough that the wings would be able to hit them.

I can't imagine they're more expensive than a collision.

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 this doesn’t provide evidence for funding the install of RWSL at that intersection, I don’t know what does. What would’ve been the cost of loss of life and both airframes? Tens of millions at a minimum.

Edit: thank you for correcting my damages estimate, I was off by at least an order of magnitude.

Each plane costs more than $150 million, plus at least 300 lives could have been lost. Damages probably close to a billion at least

Each human life is worth approximately $10 million [1], so you're in the right ballpark.

[1] https://en.wikipedia.org/wiki/Value_of_life

$10 million is not what is stated at your link.

"In Western countries and other liberal democracies, estimates for the value of a statistical life typically range from US$1 million—US$10 million; for example, the United States FEMA estimated the value of a statistical life at US$7.5 million in 2020." [1]

That's also not the meaning of Value of Life, which is a statistical evaluation. On a commercial plane there are almost certainly multiple people whose individual Value of Life projections exceed $10 million.

In many other cases, the value of life calculation for the very pilots of a commercial flight is less than $10 million.

This all goes to show that this calculation is not for what "each human life is worth". This is a statistical evaluation for determining what would need to be paid to an individual to engage in a dangerous activity or to be paid to a survivor after a person dies from an activity. When someone decides to work at a 7-11 in a crime-ridden area for a greater pay compared to a 7-11 in a safe family area, they perform a type of Value of Life calculation.

[1] From the first section of https://en.wikipedia.org/wiki/Value_of_life

The VSL used in this case is $11.8 million in 2021, the most recent year it’s been adjusted for [0]. $10m is the usual rule-of-thumb. When making policies, governments generally pick a single value. Those “micro” VSL choices are one way governments can arrive at that value [1], but it’s certainly not the only way — economists have developed a bunch of different models which have (in some cases) wildly divergent outcomes [2].

But the key takeaway is that, for government policy purposes in the US, all lives are treated as having the same value and that value is about $10 million.

[0]: https://www.transportation.gov/office-policy/transportation-...

[1]: How this VSL was calculated: https://www.faa.gov/regulations_policies/policy_guidance/ben...

[2]: General VSL calculation methods: https://law.vanderbilt.edu/phd/faculty/w-kip-viscusi/368_Val...

The VSL is for the Valuation of a Statistical Life, which is shown at the first link you posted. That's entirely different from saying that all lives are treated as having the same value.

If you follow your link to the actual VSL guidance, you will see that. [1] There is even discussion regarding how advances in data science can be used for subgroup evaluation of VSLs.

[1] https://www.transportation.gov/sites/dot.gov/files/2021-03/D...

I think we’re on the same page here. You are discussing that individual lives are valued at various numbers. I’m pointing out that when deciding whether to implement safety mitigations, the government will in practice use a single value. From the link you posted:

“Prevention of an expected fatality is assigned a single, nationwide value in each year, regardless of the age, income, or other distinct characteristics of the affected population, the mode of travel, or the nature of the risk.”

I think reasonable people can disagree on whether it ever makes sense to use multiple different VSLs for different types of person. I happen to think that those kind of adjustments do more harm than good. But it’s all (literally) academic — actual policy is set based on a single VSL.

> 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!

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…’

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.

> 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?

> 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.

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.

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.

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.

> 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.

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.

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.

The fact they didn’t take off with the mechanical issue should be a point in their favor, not against them.

More accurately though, safety critical things are not allowed to go wrong. If they do, they get investigated. What is and isn’t deemed safety critical is a document written in blood, unfortunately.

A single mechanical issue isn't an incident.

Everything involved in aviation is designed to be extremely reliable, but parts are still expected to break. Airplanes have a list of parts which are allowed to be broken without grounding the airplane. Every part has a well-documented procedure for inspection, maintenance, and replacement.

Investigations happen when, despite following the documented procedures, stuff somehow still goes wrong. They are done to improve the procedures so that it can never happen again.

Inspection and maintenance is a significant source of errors, though. Nobody wants to disassemble an entire plane when a single part develops a well-isolated failure.

Air Transat Flight 236 had its engine swapped out with a spare during routine maintenance. However, the engines had a different "patch level", leading to them installing a hydraulic hose with the wrong length. This hose rubbed on the fuel line leading it to develop a leak. The subsequent flight ran out of fuel halfway over the Atlantic, and they narrowly avoided having to ditch it into the ocean.

American Airlines Flight 4439 was done on an aircraft with a faulty trim switch. Prior to the flight, maintenance engineers wanted to replace it, but this was cancelled mid-process due to the time required to acquire a replacement part. They re-installed the switch and marked it as inoperable - which is not an issue as - despite the switch being safety-critical - there are two other trim switches available. However, the faulty trim switch was reinstalled backwards, and the pilot still tried to use it due to muscle memory. This nearly lead to a pilot-induced stall.

There are literally dozens of stories like that. In aviation, there is no room for error.

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.

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

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.

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'.

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.

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.

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

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"

Beyond detecting runway incursions, couldn't ASDE be integrated with some kind of RTS-like interface for ATC so they could indicate where planes should go next? Automated alerts could be broadcast to ATC and to the pilots if planes deviated from the plan, and the system could flag actions that risked costly but non-fatal ground collisions and other problems unrelated to takeoffs or landings.

Further, Electronic clearance delivery already sends instructions to the airplane electronically for their in-flight clearance. An electronic delivery of their ground clearance could be hooked up to navigation to highlight that route on the ground as well.

Some major airports already have Follow the Greens.

Traditionally every taxiway and every possible path on each intersection will be painted with a yellow line and illuminated with yellow lights.

Follow the Greens replaces that with green lights which are controllable at a very high resolution. The result is that every plane will have a path of green lights to follow, greatly reducing everyone's workload.

These sound more like detecting something. How about preventing miscommunication? They weren't even on the correct runway.

It’s much harder to misunderstand a red light than verbal instructions.

One solution does not discount the other. In data security we talk about security in depth, security in layers, etc. The current proposal is _a_ solution, but not _the only_ solution nor even the only component of a comprehensive solution.

Which is why I was asking about a solution that addressed the aspect of the issue that the first solution did not.

Where was the miscommunication? The pilot readback was correct.

> Where was the miscommunication? The pilot readback was correct.

"Runway 4L was being used for takeoffs. The American Airlines aircraft did not follow air traffic control instructions. ATC audio shows they were told to “”cross runway 31 Left at Kilo” and instead crossed runway 4 Left at Juliet, in front of the accelerating Delta Boeing 737."

Crossing a runway, which you're not cleared to cross is a pretty bad case of miscommunication in my book.

That's the case when the readback is incorrect or missing, i.e. the pilot heard something that wasn't said. In this case, the instruction was communicated correctly on both ends. But it wasn't followed correctly.

Someone saying the exact same words back to you doesn’t prevent miscommunication. If the pilot and ATC had the same understanding of the situation then the pilot wouldn’t have done something likely to result in a crash.

If they have the correctly communicated instructions as you imply, then why weren't they followed? Is it not also possible they don't follow the red light if they think ATC instructed them to use that runway?

Hard to say at this stage, but initial impressions seem to be that the pilot was following the instructions but were mistaken about what was in front of them.

It wasn't a miscommunication. The pilot understood and was attempting to correctly follow the instructions of ATC. The error (as far as we can tell) was that the pilot wrongly believed that they were following those instructions, but the pilot did not know where they were.

So the next logical question is 'why didn't the pilot know where they were?', and there are a lot of possible answers to that question, which could conceivably be linked to communication (e.g.: not enough signage, they were told incorrectly, their maps were written in Klingon), but the primary problem was that the pilot believed they were crossing a different runway to the one they were actually crossing.

Would be cool if they had HUDs with a "driving line" and other pertinent info on the taxiway and runway.

I'm not disputing that it's very expensive but I find it funny that the "install red lights" solution is considered to be vey expensive.

People die at intersections with stop signs every day, but we don’t do it on our roads for the exact same reason.

McKinsey style interview question. How many road intersections are there in the US?

"our market analysis shows that price inelasticity and customer retention rate of opioids are insane! "

Google says that Quora user thinks: Can’t answer the second question, but as for the first one, there are 6,302,865 intersections for the 497 urbanized areas in the United States.

ChatGPT says: I'm sorry, I don't have an exact number for the number of road intersections in the US. However, I can provide you with some information that may help you arrive at an estimate. According to the Federal Highway Administration, as of 2020, there were approximately 4 million miles of public roads in the US. If you assume that each mile of road has an average of four intersections (which would include cross streets, driveways, and other points where roads connect), that would result in an estimated 16 million road intersections in the US. However, this is just an estimate and the actual number may vary depending on factors such as population density, urbanization, and road infrastructure.

I'm guessing three to four orders of magnitude more than there are intersections between runways and other runways or taxiways.

My instinct would be to compare a representative neighbourhood's population to the number of intersections and extrapolate.

It’s aviation; everything is 10x the cost due to (mostly sensible) certification requirements.

WSJ article made it seem as if these lights were already in place:

"Airport officials also inspected lights meant to indicate when it isn’t safe for planes to venture across runways and verified they were working at that particular runway, according to the summary."

So, the American flight didn't follow directions or the lights. If that turns out to be the case, wow.

I think what the parent want to say is that these lights do not exist. The sentence is written in a way that makes it seem they do (i.e. it's all theoretical in nature).

Could also be that they were not correctly set, the pilots thinking "hey, no red lights, we can go! Its 100% safe".

Who are "they" in your sentence? I assume the lights and not the plane? Wouldn't lights like this be placed the same way on every airport implementing them?

I think they meant that the lights may not have been set to the correct state.

This is a good example of how ADDITIONAL safety systems can sometime become the de-facto safety system. A similar problem can happen with firearms, where if a mechanical safety is on, people sometimes disregard other rules of safe firearm handling, leading to accidents.

Pilots have a lot of info coming in at any given time, and there has been a move to reduce the amount of info, so they can focus on the more important items. The answer isn't always more warning lights or alarms.

Edit: By "This is a good example..." I am referring to the hypothetical situation, I am not confirming this actually happened.

> but apparently NOT at the intersection inquisition

https://www.google.com/search?q=%22in+question%22

Nothing is working. Send in the nuns!

https://www.youtube.com/watch?v=LnF1OtP2Svk

This diagram suggest that it is installed at the intersection in question (J cross 4L)

https://www.faa.gov/air_traffic/technology/rwsl/media/JFK.pd...

Yep. Both the intersection American 106 was supposed to take (cross 31L at K) and the intersection they took (cross 4L at J) have runway entrance lights.

According to https://www.faa.gov/air_traffic/technology/rwsl/pet/ the lights don't illuminate until departing aircraft are at 30 knots, so it's possible Delta 1943 was just beginning the takeoff roll and the lights weren't on yet when American 106 decided to cross 4L.

I believe that the causes for errors in perception and communication can be rather subtle, and therefore successful mitigations can be as well.

If the root error of the pilot here happened not at the runway crossing, but earlier, when confusing the K and J taxiways, then that's the location where possible preventative solutions should be considered.

Because once a pilot has subconsciously convinced herself that she's at another runway, it becomes increasingly impossible to override that mental block, no matter how many lights and sirens you use.

If you take a look at the airport diagram (https://www.faa.gov/air_traffic/publications/atpubs/aip_html...), it just takes one wrong turn to end up on taxiway J instead of taxiway K. And, also from that diagram, once the American plane took the wrong turn, the controller had very little time to see that and stop it before it crossed the runway.

But still, if pilots internalize via training that "if you are about to cross a line of red lights, you are entering an active runway without having permission to do so, so don't do it", that should be one more layer of safety to prevent situations like this. Of course, none of these layers are 100% foolproof, but taken together...

RWSL take it a step further and are actually automatic based on ASDE. No controller input necessary.

I'm not aware of the costs to install it but I really wish it was everywhere. It's an incredibly handy confirmation for clearances given by ATC.

I flew into JFK in December and was surprised the number of concurrent operations going on… landing queues of 5+ planes in the sky for the two runways, long takeoff queues, so many land operations… once you touch down it sure feels like the pilot knows they have to get that plane off the runway ASAP. Felt much more busy than I have previously going through LAX/SFO/London/Dubai. I wonder if the level of traffic at JFK is appropriate. Maybe Newark and LaGuardia need to take on more of the load. And maybe a city airport shouldn’t be the primary international entrance point for what feels like half the country

Pretty much all three airports (EWR, LGA, JFK) are already at capacity, so there's no room for others to take any load.

A solution that'll anger people but resolve the capacity issus, all flights with not a final destination in USA can only connect through Stewart airport.

That airport has one cafe. It's a nice little regional airport (I know they serve international destinations I've flow out of it to KEF, but it's very small). I'm not even sure how many planes land without a final US destination in the US? The passengers may be going on, but are the planes?

Airport is at full capacity -> route more pax through other airports.

A lot of people benefit from keeping JFK full. Airlines, pax wanting direct flights to other destinations etc.

Currently ~20% of New York passengers are connecting passengers, you could route them through other airports and free up capacity with much less disruption then making the New York local passengers have an extra connection on the way out.

Do they have a sterile transit area to support international transfers? I didn’t think any US airport had that and US requires transit visas and immigration clearance to transit

Newark and LaGuardia are just as packed. The nyc airspace is just over used.

Sounds like the airports need to increase the pricing to the point where it's gonna reduce a bit the traffic.

What pricing?

Airports are in-effect giant malls. They rent out space to shops, and airlines. Ostensibly the airport authority has set the pricing to maximize net income. For example DIA's authority is the city and county of Denver. JFK's is the Port Authority, which includes EWR and LGA, but also much of other transit in the area including LIRR, and MTA, but includes seaports, bridges and tunnels, and ... real estate.

ATC is run by the FAA whose budget is set by Congress. Everything is paid for. There are no per use fees. Landing fees are not federal, they're imposed by (local) airport authorities. The weather, flight service, ATC, national airspace system, navaids, all of that stuff is provided by the federal government.

ATC and FAA don't want to be in the business of collecting fees. And airport authorities don't want them to because it would necessarily cut into their take, and it would also mean they lack exclusive control to set pricing and thus demand and thus limit their ability to maximize income. It's a shopping mall.

after reading your comment, I was surprised to learn that JFK did indeed land the most international passengers in 2021.

https://www.statista.com/statistics/639826/leading-airports-...

A colleague of mine was blocked in NY overnight on a flight from Rome in early Jan, as the incoming flight clipped the tail of another airplane right after landing.

https://www.reuters.com/business/aerospace-defense/ita-airwa...

This stuff is happening a bit too often in JFK as of lately...

From the article: > The Italian airline, noting it fully respects all safety regulations, said in Thursday's statement that "collisions during taxiing manoeuvres are an increasing phenomenon ... especially in highly congested airports like JFK."

The safety issues at JFK stem from the fact that it is a very old airport, built for the turboprop era.

That’s LaGuardia! JFK was built to address this.

Newark is super congested too.

I remember flying from Michigan to Newark once and the ticket said “2 hours 45min” and I thought that was nuts, it’s like an hour flight.

Turns out they tack on an hour leaving and coming for taxing and waiting in line.

At least that’s how it was a decade ago.

At least they have the space to try to improve it, new terminal actually looks world class https://thepointsguy.com/news/newark-airport-terminal-a/

That’ll be a nice upgrade. Newark and La Guardia look so old. Same with Terminal 1 in Boston.

The Detroit airport looks amazing next to them.

You haven't been to La Guardia recently. It's by far the nicest airport in the tristate and one of the better ones in the country after the remodel. JFK is the one new yorkers avoid now (or EWR if you don't live in Manhattan).

Didn’t even realize they rebuilt a terminal too, it does look pretty cool:

https://thepointsguy.com/news/first-look-delta-new-laguardia...

> once you touch down it sure feels like the pilot knows they have to get that plane off the runway ASAP

Do yourself a favor and do a youtube search for "kennedy steve." He's famous for managing this chaos with a commanding voice and prompt instruction while maintaining a good sense of humor.

The pilots at pprune mostly don't seemto like jfk so much. They complain of arrogant controllers speaking too fast in nonstandard terms leading to dangerous situations. And the air traffic control, ground and gate operations don't seem to communicate properly. Just check how often planes bump into each other at the gate there

Thanks for the mention! I was entertained by him for a bit last night on YouTube. In his interview he talked about how much the M3 airlines didn’t appreciate his style, good times

I want to offer a bit of a different perspective than the one I'm seeing in other comments which (totally reasonably) wonder if a) JFK is too busy or needs some safety upgrades and b) whether voice contact with ATC is the best way to reduce risk during unusual events like incursions.

I'm just an amateur enthusiast who listens to a lot of ATC, so take this assessment with that grain of salt:

JFK has long had a unique subculture with respect to ATC (embodied most famously by the flourish and wit of Kennedy Steve, but often apparent from the entire ATC corps on both ground and tower during busy times), and strange as it sounds, it might be a part of what averted this disaster. At other airports, it seems to me that it's totally possible that this goes far worse.

The controller did a few things that are unusual in ATC, but not totally unheard of at JFK in particular:

* Completely changed tone of voice. He yelled into the mic. That doesn't happen often in ATC.

* Yelled "SHIT!" to open his transmission.

* Spoke in a way that emphasized speed and urgency even if it cost a little clarity (eg, some news outlets have transcribed "cancel takeoff clearance" as "cancel takeoff plans" because of how intense and fast the controller is yelling)

Assuming the aircraft were on a collision course (something we'll probably know for sure only when the FAA report comes out), this was less than 1.5 seconds (perhaps less than 1 second) from an impact.

A different transmission, like you might hear at say LHR or LAX, where the controller keeps a monotone and simply says, "Delta 1943 cancel takeoff clearance" might not have gotten the attention so quickly and helped the Delta pilot initiate the reject so rapidly.

I think that this incident is an example of a) how JFK's unique ATC swagger may not be just for show, but may actually be a part of the safety culture of that airport, and b) how effective voice contact with ATC is at achieving rapid response from pilots.

Ideally, this investigation prompts some study into what might seem like a silly topic: whether the "New York attitude" of JFK controllers has a positive safety impact that isn't felt elsewhere.

Fantastic comment. Also on the language front, New York English is spoken faster and with more emphasis - likely to be helpful here compared to say, Texan.

Does this same subculture apply to LGA?

It's hard to say, because it's such a different operation and different scale. LGA has two 7,000 foot runways, and no CBP (meaning very few long-haul flights are landing there), as well as all the perimeter rules and curfews... listening to LGA ATC feels more like listening to a small quircky airport, at least to me.

So it's hard to make any kind of comparison.

It will be more telling to see how things settled after the construction is finished.

> The controller did a few things that are unusual in ATC, but not totally unheard of at JFK in particular:

> * Completely changed tone of voice. He yelled into the mic. That doesn't happen often in ATC.

> * Yelled "SHIT!" to open his transmission.

> * Spoke in a way that emphasized speed and urgency even if it cost a little clarity (eg, some news outlets have transcribed "cancel takeoff clearance" as "cancel takeoff plans" because of how intense and fast the controller is yelling)

I think this was actually relatively subdued. There was a similar incident at Chicago Midway in 2015 where the ATC command was "Delta 1328 STOP STOP STOP": https://youtu.be/b26NcJCLZl4?t=82

The phenomenon I'm describing as palpable at JFK ATC is not dependent on volume or vocal intensity (both of which are clearly palpable in the recording you've linked).

Sp. leaving aside whether or not it's more "subdued" (they're both unusual in tone, I'm sure we can agree), the JFK controller did something that the Midway controller didn't: repeated the entire transmission including callsign, in case his first tx had been stepped on, unbeknownst to him.

He was able to do this in such a quick timeframe because he was employing the phenomenon I'm describing. Dialing deep into it: the way he allowed his full NY accent to come out ("cleh-ance" instead of "clearance", for example) delivered the full message at a very high signal to the ear _twice_ in about the same span as the Midway controller (while yes, using a louder volume) got a less clear message across only once.

I dream of being an ATC. It's something I'll do later in life in the context of a multiplayer game, I think.

It reminds me of an air disaster that happened about 20 years ago for the same reason. [0]

In that case, the pilot of a plane misread the taxiway number (he confused R5 with R6 [1]) and entered the runway while another plane was taking off.

[0] https://en.wikipedia.org/wiki/Linate_Airport_disaster

[1] This is what the junction between R5 and R6 looked like that day: https://it.wikipedia.org/wiki/File:Disastro_Linate-02.png

The animation in the tweet at the end of the article is something. Based on that, the deceleration looked remarkably fast. I imagine that was quite the ride for the folks in the Delta jet.

I've experienced maximum breaking in an emergency landing.

Many passengers (including me) instinctively put their hands on the seat in front to steady themselves. You could easily slide around if the seat belt were loose.

It was it worst for children whose legs didn't reach the floor, but there were none seated near me.

I was on a plane that had engine issues during takeoff, front wheel off the ground. We slammed back down to earth and likewise they braked harder than I'd ever experienced. Lady's phone flew out of her hand. It was intense.

Hmm that's interesting since by the time the front wheel comes off the ground, an airplane would normally be past V1 speed and they'd have to commit to the takeoff.

That’s generally true but the rule is that you never abort past V1 unless you have specific immediate reason to believe the aircraft cannot become and stay airborne.

There aren’t a ton of reasons one might think that but a few come to mind like total engine failure or lack of elevator control or similar.

I can only imagine that the pilot had reason to believe something was wrong the moment the forces began to lift the front wheel and change the aircraft dynamics, which definitely is in the extremely fast changing grey zone for a lot of conditions highly dependent on the exact aircraft and it’s current conditions. Light payload and fuel loading pushing V1 very close to takeoff speed and lower than the maximum numbers, headwinds, engine conditions, etc… it’s definitely a case of “sometimes pilots do have to make quick decisions” and my money is on engines or the hydraulics when they first took load on the moving surfaces as the aerodynamics shifted passing V1 towards takeoff speed.

> lack of elevator control

This was the case with Ameristar Charters 9363, which aborted after V1:

> [T]he jammed elevator could only be detected once aerodynamic forces came into play — something which would only happen once the plane was already speeding down the runway. The NTSB was forced to come to an incredible conclusion: that there was no way for the pilots to have detected the problem until they attempted to rotate for takeoff.

https://admiralcloudberg.medium.com/lesser-of-two-evils-the-...

In that case wouldn't the plane be at such a speed and distance along the runway as to not be able to physically stop before the end?

Wow. That's almost unheard of. There's a speed called "V1"; this is the last possible moment for a pilot to start aborting the takeoff. There's another speed called "Vr", which is when the pilot starts the rotation (lifting the nose off the ground) [1]. Vr is higher than V1. Past V1 its unsafe to abort, even if a tire blows or an engine fails. The only time it would be aborted would be if the pilot thinks the plane is unflyable, such as both engines failing or controls not working.

[1] https://www.aopa.org/news-and-media/all-news/2011/february/0...

Whoa fascinating. What makes it necessary to commit after V1?

As per the linked website: " If the airplane reaches a peak speed of only 10 knots beyond V 1, the brakes must now dissipate 20 percent more energy than had the abort been initiated at V 1. Beyond the fact that there is no certification requirement for the brakes to be able to absorb any energy beyond that existing at the highest weight and V 1 combination demonstrated, there also is no performance data to know how much runway would be needed even if the brakes are able to handle the extra energy. Adding to the chaos, one brake must now absorb all the energy of the aircraft, as the blown tire’s brake has been rendered useless."

Basically you'd be unlikely to get the airplane to stop before the end of the runway because brakes are not designed to handle breaking at such speed (keep in mind that an airplane lands at a slower speed than it takes off thanks to the flaps).

It’s typically because there is not enough runway remaining to stop the plane if you abort past V1.

The V1 decision speed is not fixed, it's calculated for each take-off based on weight, wind, runway conditions, maximum thrust settings etc.

It meets these constraints:

1. Low enough such that if you try to stop from that speed you will stop before the end of the runway

2. High enough such that if you have an engine failure at that speed, you will make it airborne on the other engine before the end of the runway

3. Not higher than rotation speed (you can't decide to abort after pitching the nose up and getting the aircraft airborne)

4. Not lower then minimum control speed (you can't keep directional control in case of an engine failure below minimum control speed, so your only option is to abort)

If there is no speed that meets all conditions, then your runway is too short and you can't go. Reducing weight helps, since you'll accelerate faster, stop easier, and take-off at a lower speed. So that's usually the solution if your runway isn't long enough.

Constraint 1 is why you're committed to takeoff above V1. If you would try to stop above V1 there is no guarantee that you'll stop before the end of the runway. While you are guaranteed to be able to take-off above that speed, even after an engine failure. So you take the problem into the air, run checks, and return.

We were all deplaned after, and they had to find everyone new flights. They wound up getting me a hotel nearby. So I guess it was unflyable? Easily my worst travel experience.

Was it a multi engine jet? Just wondering, because they should be able to climb out on one engine, but some other planes can’t.

Not a clue, sorry.

Ameristar Charters 9363 is one example of this happening:

> Captain Mark Radloff was thus faced with an almost unprecedented situation: having already accelerated well past V1, he suddenly realized that his airplane would not become airborne. At that point he faced a choice — keep trying to force it into the air and risk failing, running off the runway at well beyond takeoff speed, or try to stop, and guarantee a lower-speed overrun?

https://admiralcloudberg.medium.com/lesser-of-two-evils-the-...

Rejected takeoffs and clear air turbulence are why I never do infant-in-arms.

What is the alternative? Is there an equivalent of a infant car seat for the plane?

In Europe the standard is infant with extra belt. It attaches to the parents belt. Some US based airlines offer this as well, but it's not mandatory by the FAA.

You can use a car seat on a plane. It's an absolute pain in the arse and almost entirely unregulated, I've seen various 'rules' like 'must be forward-facing', 'must be rear-facing', 'must be 5-point harness', 'must be 3-point harness', 'must be no more than 41.5cm at its widest point', 'must have "certified for aircraft use" printed on it', and so on.

But it is technically possible to take a child on a plane in a car seat, if you can find a suitable plane, suitable car seat, and suitable child.

A long time ago I was on a FAA certification test flight where we tested maximum braking. I wasn’t in the flight deck, so I don’t know if it was literally true, but it was described as “pilot standing on the brakes” and it sure felt that way. All our equipment was strapped down and when the pilot hit the brakes for our first test my glasses flew off my face. Those brakes are no joke

Maximum breaking, is powerful stuff… Real red hot metal and tolerances engineering stuff. You have to be able to stop the airplane at it’s maximum take off weight at the maximum takeoff ground speed (got to account for tail winds) within the acceptable safety stopping distance on the runway, and they have to sit there after this without any help for several minutes to represent the time it can take to scramble ground safety and rescue crews to assist... On big jets this involves sacrificing the breaks and often even the tires, as the breaks get glowing red hot and the heat radiating off them will be strong enough to heat up the air in the planes tires to the point that safety systems like fusible plugs/patches designed to melt (but not break from normal pressure) kick in and the tires blow out the plugs and deflate due to the exposure to sheer heat coming off the breaks as they sit there for a few minutes soaking in the heat from the red hot breaks…

Good video of the test conditions for a 747-8 here https://youtube.com/watch?v=qc_v6tXsv6g

The classic:

https://m.youtube.com/watch?v=qew09gao3S8

In short, the whole brake assembly catches fire- and continues to operate.

Definitely a much better view of the brake assembly and the extreme forces they deal with. I’d forgotten how much the sound reminds me of a sort of bad off key imitation of the “Deep Note” Dolby THX intro sound. As the rotation speed slows it pitches down the frequency scale into more audible tones and sounds slightly louder as the microphone picks it up better and then it fades out towards the end.

I do think it even though it’s a better brake mechanism video it’s not quite as visually impressive as watching a 747-8 just about to nose up suddenly nosing down as it slams on the brakes and they come to a stop in a dissipating cloud of smoking revealing the red hot brakes glowing in the wheels.

s/breaks/brakes

Phone autocorrect ducking sucks at times. ;-)

Fasten those seatbelts!

Something I realized growing up, and perhaps this is a bias for others too: I always perceived of airline accidents as being crashes where everyone dies. Hence all the conspiracy silliness of “they just want to know what seat you were in to identify the body.”

But my goodness there’s so many ways to be badly hurt without a big crash.

In a way this feels akin to the highway bias: highways are far safer than city streets but a lot of people perceive them as being so dangerous.

> But my goodness there’s so many ways to be badly hurt without a big crash.

I remember an incident involving a private jet about a decade ago. The jet was at cruising altitude when suddenly it hit an air pocket and precipitously lost altitude. This being a private jet the occupants (some Greek businessmen) were drinking champagne or whatever, fact is they weren't wearing their seatbelts. A few of them died right on the spot as the result of them violently hitting the plane's roof.

IIRC there's more than one incident report that'll mention something like "40 dents in the ceiling" from where all the unseatbelted folks got launched.

If you're seated in an airplane please make sure you've got your seatbelt on. You can have it a bit loose and it'll still protect you from this sort of nonsense much better than no seatbelt at all.

This is the top (but not only) reason keeping your baby/toddler in your lap instead of in their own seat, buckled into a carseat, is a terrible way to fly. Lap infants are far more likely to be injured in-flight than other children: https://journals.lww.com/pec-online/fulltext/2019/10000/in_f...

The carriers don't make this easy: they have conflicting rules on carseats for in-cabin use, especially if you're flying between the US and Europe, both of which have stringent carseat regulations, but absolutely no models that are approved for use in both. In practice, United allowed the EU carseat (used, bought specifically for the trip) and Lufthansa allowed a US carseat (more compact, bought for car use in the US), but both of their sites stated that they only allowed carseated approved by the airlines' local authorities: NHTSA (United) or TÜV (Lufthansa).

I'll note, however, that carrying multiple child seats onto an aircraft is simultaneously exhausting and humiliating.

Yeah, dealing with just one seat, plus the fractious toddler, minus a baggage cart, made me very glad that I was not traveling alone with said toddler, and that he should be large enough for a CARES belt to be adequate restraint the next time we plan to fly.

> Lap infants are far more likely to be injured in-flight than other children: https://journals.lww.com/pec-online/fulltext/2019/10000/in_f...

In case anyone is curious, this source does claim that "lap infants" are more likely to be injured than other passengers. But the article defines "lap infant" as anyone under 2 years old, regardless of whether they were in fact in someone's lap. (In particular, some of these "lap infants" fell from the cot!)

Potentially worth quoting as well: "Scalding burns from hot beverages or soups spilled over a child during hot meal service were the most commonly identified mechanism of injury".

Am I reading this correctly that not only is the definition of 'lap infant' not dependent on whether a child was in someone's lap or not, it also would include a child younger than 24 months who was restrained in a car seat at the time of the in-flight injury?

> For the purpose of this study, the term in-flight injury was used to denote medical events caused by injuries (ie, trauma or burns) that occurred or manifested themselves during flight. Lap infants were defined as passengers younger than 24 months, the age until which a child is allowed to travel while sharing a seat with an adult passenger.

True, this animation clearly reminds me of [Tenerife airport disaster][1], a childhood nightmare from a documentary. 10s late it could became that.

[1]: https://en.wikipedia.org/wiki/Tenerife_airport_disaster

I experienced a takeoff abort in New Orleans in a 737 when some birds (I think that's what the pilot said afterwards) clogged up the pitot tubes (in the 1980s) and either the plane aborted the takeoff or the pilot did. It was a max effort whatever it was, scared the shit out of everyone.

That was not a good decade for MSY aviation.

I was in a rejected take off. I collected my phone from the cockpit door after it flew there from my hand. Without the seatbelt, I would have flown too.

I never found out the reason. I thought they would have to report it and I could read it in av herald.

Actually saw a phone go into the cockpit from the back of the plane. Slid right straight down the aisle and under the door. All from normal braking during a normal landing.

I was in a jet taxiing and headed for a runway crossing. I could see out the window a plane on coming in to land on the runway we were about to taxi across. It was clear from our speed that the pilots had no intention of stopping before crossing the runway. I could see it all unfolding and was actually considering taking off my seat belt and running to the cockpit. At that moment the pilot suddenly applied massive braking and we came to a stop just before crossing the runway as the landing plane sped down the runway right in front of us. Frightening.

> taking off my seat belt and running to the cockpit

People really don't like it when you do that, by the way.

That animation from FR24 is interpolating the motion between sparsely-updated position/speed/heading info, so the changes will appear more sudden than they actually are.

> strong kudos are due both to the air traffic controller who called off the Delta 737 and to the pilots of that plane who managed to abort their takeoff and stop the aircraft before it crossed runway 31L where the Boeing widebody passed in front of it

Can't agree more

How difficult is it to stop an aircraft like that so quickly? More than yanking an emergency brake handle I'm assuming.

Before takeoff on all modern airliners, the autobrake system is set to a mode called "RTO" (Rejected Take Off). If at any stage during the takeoff roll the throttles are pulled back to their idle position (an instinctive move during an abort), maximum wheel braking is applied, along with extension of the ground spoilers on the wings (the panels which "stick up" on the wings when you land). Pilots will also usually apply maximum reverse thrust on the engines, adding in a third form of braking.

That’s pretty smart! Thanks for the explanation.

A 737-900, fully loaded and fueled for a transatlantic flight, weighs 70 - 80 tons and takes off at 150 - 180 mph. That's a lot of energy to dissipate in a hurry.

Fun fact, during a high speed rejected takeoff certification the brakes routinely catch fire.

Given that you absolutely never swear (or even waste words) on the radio, I wonder if beginning the transmission with an expletive is actually optimal: it is short, sharp, and immediately conveys the urgency of the command.

Reading the transcript, I thought it might've been a waste of time to start with "Shit...", but listing to the audio does make the following command a lot more urgent and severe. Either way, with all the things going on (and through a pilot's head) at take-off, I'm glad they were able to respond to the message and stop the plane in time.

I don't know how accurate the various videos are, but if they are, the Delta pilot was probably able to visually see the plane on the runway ahead, perhaps even before the tower noticed it. The plane seems to begin decelerating very early, before I'd expect the "cancel takeoff clearance" message to have been fully understood by the pilot.

DELTA1943: "Alright, and uh, woof!"

ATC: "Delta 1943, are you able to taxi or do you need a couple of minutes to run checks?"

DELTA1943: "Yeah, we can get off the runway" but they're all going to need a change of underwear!!

And I thought the Brits were known for understatement!

I believe this kind of situation is known in pilot parlance as a “code brown.”

I'm always reminded of the announcement the pilot of BA 009 made when all four engines had failed:

"Ladies and gentlemen, this is your captain speaking. We have a small problem. All four engines have stopped. We are doing our damnedest to get them going again. I trust you are not in too much distress."

Thanks for this. I didn't know about the incident and it led me down the rabbit hole. The article shared on the pilot's personal page is wonderful - it took me on a rollercoaster ride of emotions.

http://www.ericmoody.com/

You might also be interested in the story of UA 232. They lost all controls and somehow used engine thrust to keep the plane airborne. They called the Maintenance department for advice and were basically asked where they were going to crash. My grandparents were standing on their porch waiting for the doomed airliner to fly over their house. Instead, the crew wrenched it around the city to save lives on the ground when they inevitably went down. ATC offered to let them crash land on the highway, but the flight crew insisted on crashing at SUX. By the time the plane came into view at the airport, ATC had already declared a crash. Just about every fire apparatus in Woodbury County was sitting on an abandoned runway, waiting for the inevitable. Then they realized that the plane was lined up on the same old runway, which resulted in a panicked move of a whole lot of trucks. Knowing he was about to crash somewhere (maybe near a runway, maybe not) Captain Haynes exemplified grace under fire, as shown in this exchange.

ATC: United 232 Heavy, Roger, Sir. Wind 010 at 11. You are cleared to land on any runway. Al Haynes : [chuckles] You want to be particular in making a runway? [staff at the control tower laugh nervously]

I've really enjoyed watching various places transcribe the sound that DL1943 made after "Alright" there. I've seen "Uch", "Huff", "Phew", "Uew", and now "Woof"!

I've always been annoyed my entire life by the use of "woof" because I thought people were, for some reason, imitating the barking of a dog and it made no sense to me because I've never heard anyone in person do this, ever. 3+ decades later I now realize it's just a way of spelling any of the above.

For anyone interested in the milieu of plane crashes, Admiral Cloudberg's writeups are amazing.

https://admiralcloudberg.medium.com/

Well, that just took me down the intertubes for an hour. Thanks!

Here's a diagram of the taxi paths:

https://avherald.com/h?article=503c9620

- "Excerpt of Aerodrome Chart, red: actual taxi path, green: cleared taxi path (Graphics: AVH/FAA):"

Are we're relying on pilots who are holding many many things in their heads to follow only the verbal directions of air traffic control?

Two alternatives that I would think would be fairly easy to implement.

1) Google maps style directions input by air traffic control showing as well as telling the pilot what runway/path to runway to take.

2) Coloured lighting directing the pilot to the right runway via the correct path. Then the pilot only needs to know that they are following blue, and when it's time for them to move, blue comes up.

I understand this would be more work on the part of ATC, where right now they can verbally communicate, but a system such as this may also help ATC relieve some of the mental load.

Is this already happening? I can't find any links to suggest it is.

> 1) Google maps style directions input by air traffic control showing as well as telling the pilot what runway/path to runway to take.

Now you've added one more thing for the pilot to look at instead of actually looking out the windows.

Head-up display? Augmented reality?

Related to (2) is an RWSL[0] system, which was supposedly in use at the time of this event and is designed to stop exactly this sort of thing… whether it was functioning, the pilots didn’t see it, etc, will surely come out in the ensuing investigations.

ETA: another comment suggests that while JFK has RWSL, it was not installed at the intersection where this occurred.

[0] https://www.faa.gov/air_traffic/technology/rwsl/

Re #2: We already have something like this at some airports. I wonder whether it was available on the runway/taxiway in question?

https://en.wikipedia.org/wiki/Runway_status_lights

Seems like the particular intersection where this incident occured is supposed to be protected by RSL:

https://www.faa.gov/air_traffic/technology/rwsl/media/JFK.pd...

Runway Entrance Lights at intersection J/4L which is where the incursion happened. These are taxiway centerline lights, and should have been red at the time. Here's the gotcha: REL only illuminate once the departing aircraft reaches 30 kts. https://www.faa.gov/air_traffic/technology/rwsl/pet/

Based on the animation https://twitter.com/CaseWade/status/1614342894248394752 at 00:14, I'm pretty sure AA 106 was no longer in visual contact with REL lighting by the time DL 1943 reached 30 kts.

My understanding is that there is a shit ton that is and always has been happening in this area. Air safety is the leading sector in standards for safety training.

We are relying on checklists, procedures, surveillance tech, simulation training, certification, re-certification etc. etc. No other industry has put in as much thought into these problems. Except for maybe the military.

Source: I had the opportunity to meet and participate in crisis resource management training for surgeons held by a trainer from pilot training industry. Everyone’s mind was blown because surgery is comparatively in the Middle Ages.

Based on seeing and hearing about it I believe that more ideas have been studied and tested than you’d expect. Cognitive overload in crisis situations is a well researched problem. Probably hard finding links on the subject though.

Space flight is the one industry with a better track record I’d say.

I wonder by what metric this is true. For instance, I’m sure the fatality per flight of manned space flight is an order of magnitude worse than commercial air flight in the US.

Easily *six* orders of magnitude. STS saw two crashes in O(10^2) flights (and SpaceX has much smaller numbers still). The US handles O(10^7) commercial flights per year, none of which crashed in 10+ years (I think).

https://www.faa.gov/air_traffic/by_the_numbers

Ridiculous. This is comparing the modern commercial private space flight industry with the still maturing mostly public industry. Compare how dangerous the first twenty years of air flight was. We haven’t achieved the same level of commercial space flight due to just how cautious we’ve been.

Aviation statistics get pretty scary as you go down the regulatory hierarchy. Charter operations (part 135) have a worse safety record than big airlines (part 121). General Aviation pales in comparison to both. (And yup, some careless private pilots turn their C172 into an unlicensed charter airline.)

Good overview: https://www.youtube.com/watch?v=lpGl2_fVr2Y

Right now, private spaceflight is basically regulated in a manner similar to Part 91 (GA) operations. The customer signs a waiver saying that the vehicle is not certified and that they've checked it out to ensure it's safe. Early days, of course.

Speculating - what if we only consider craft piloting errors? That would rule out many fatalities - Apollo 1, Challenger, Columbia.

You sure? When air flight was pre-commercial it was a dangerous business indeed. Had we been as cautious as with space flight we wouldn’t have had commercial air flights until very recently.

It’s important to account for the frequency difference for these events. One of them has thousands of flights per day, the other not as many.

Take a look at:

https://en.m.wikipedia.org/wiki/Crew_resource_management

Ha! Yeah crew resource management is what I meant but misremembered as critical resource management.

The reason surgery is so far behind aeronautics is likely entirely due to the fact that when a surgery goes wrong, it usually doesn't kill hundreds of people at once in a massive fireball. Everything else being equal, rare but spectacular failures tend to garner more attention than more frequent but less dramatic ones.

"The reason surgery is so far behind aeronautics is likely entirely due to the fact that when a surgery goes wrong, it usually doesn't kill hundreds of people at once in a massive fireball."

You also have to wonder how many deaths from surgery are officially classified as "Doctors messed up" vs something else that partially or fully absolves them from responsibility...

> The reason surgery is so far behind aeronautics is likely entirely due to the fact that when a surgery goes wrong

Surgery is not a public performance. How do you even find out about the mistakes that occur? Fatal mistakes, sure, maybe...

You have a better bet of your dash cam showing what happened when your car is hit by another car, if something happens to you.

I think nobody's really going to know what mistakes were made while you were on the table. Certainly not in a near miss like this case.

Very interesting reference on improving healthcare and getting honest measurements: a 2004 article by Gawande on the treatment of cystic fibrosis. [1]

[1] Atul Gawande, https://www.newyorker.com/magazine/2004/12/06/the-bell-curve

Atul Gawande’s „Checklist Manifesto” is also fantastic. He goes specifically into how airline and construction safety checklists make those industries safer and then lays out a checklist method for reducing complications in the OR.

There is some discussion on implementing black box style recording into the OR. I’ve met surgeons enthusiastic for this idea as an opportunity to geek out even more. But this enthusiasm depends on how authoritarian culture is in a given country. The OR is also often a place where people are in a corrupted power structure. I have been to countries where dangerous surgeons are covered by younger surgeons - that’s where recording in the OR is less popular.

On the other hand I have heard arguments against such recording as well. Anatomies differ, shit gets ugly to unqualified bystanders. Insurance keeps an eye on everything. Surgeons can become so careful that they prefer not to help so as not to endanger their career.

I might have over done it on the surgery bit but yeah, an individual malpractice episode is hush hush, insured and supervised, he said she said sort of thing.

I worked at a startup on some of the earliest rollouts of Airport Collaborative Decision Making systems:

https://en.wikipedia.org/wiki/Airport_Collaborative_Decision...

These are more about timing and throughput in airports, and less about safety critical stuff, and certainly there are new fancy navigation and runway lighting systems to help with that. But what I’ll say is that airports involve a huge number of different organisations, operating huge numbers of systems from different vendors, and until about 15 years ago there wasn’t much joining it all up end to end. To the point that a killer demo early on was merely putting the airport and all the planes on a real-time map. So, it doesn’t surprise me that a lot of the responsibility still falls on humans and processes.

On 1:

While taxiing, you're supposed to have the taxiway map up (https://flightaware.com/resources/airport/JFK/APD/AIRPORT+DI...), and something like ForeFlight (which many pilots, GA and commercial, use) will alert you when you're approaching a runway as well as once you enter it. Not sure what the instruments in a 20+ year old 777 will have to help with this (likely the taxiway map, unsure if they'll alert on runway entrance).

On communication: most modern flight computers do support getting your IFR clearance from the FAA (see CPDLC: https://en.wikipedia.org/wiki/Controller%E2%80%93pilot_data_... and Tower Data Link System: https://www.faa.gov/air_traffic/flight_info/aeronav/acf/medi...). This doesn't include taxi clearance.

Looks like ForeFlight and MITRE are working on bridging the gap (take the audio taxi clearance and overlay it on the map): https://www.mitre.org/news-insights/impact-story/runway-safe...

EDIT: here's a video of the feature in action: https://www.youtube.com/watch?v=9p5-7jVg8fE; looks like it's only on the most expensive plan though :/

#1 sort of already exists, it’s called progressive taxi: https://www.skybrary.aero/articles/progressive-taxi-instruct...

> Are we're relying on pilots who are holding many many things in their heads to follow only the verbal directions of air traffic control?

With how much can be going on at major airports, probably. If ATC routed you on one taxiway the last 10 flights, then switched it up, you could easy repeat back what they told you while still thinking of the old route. Commercial aviation's safety record disagrees with me, though.

#2 is already a thing in Europe, (for example on Heathrow you can hear ATC say "follow the greens", which will guide the planes to the correct Runway entrance: https://youtu.be/7pX9hxn-cmE?t=363)

Or this one, showing how it works in foggy condition: https://www.youtube.com/watch?v=2W2ak94xTXM

And an explanation of the system: https://www.youtube.com/watch?v=zAn1mfBDDkc

> (“Shit! Delta 1943 cancel takeoff clearance!”)

This isn't a real quote, is it? I was surprised to read ATC losing their composure like that, but in the linked video/audio there is no utterance of Shit! that I can hear.

It’s definitely on there

Oh you're right. The tweet linked in the article doesn't have it but this version does: https://www.youtube.com/watch?v=9N1gDSZJ5s0

vs https://twitter.com/RossFeinstein/status/1614613794470100995

The tweet has it as well, at 5s of the second attached video: https://twitter.com/xJonNYC/status/1614370783899303938/video...

There is a very loud and clear “shit” in the actual atc stream

It was very very close so monetary lapse in composure isn’t entirely unexpected

The ATC is dawning on the fact that if they don't call off the takeoff within 5 more seconds, V1 speed will be hit and there goes both planes... I'm surprised they weren't less composed...

Honestly the "Shit!" is good communication. Breaking composure and normalcy can ensure everyone hearing the message treats it as urgent. That might make the difference when seconds are on the line.

That's hilarious but you're right. It's absurd enough that it could be included in training.

The US is more loose on ATC phraseology than the rest of the world. The "shit" was probably the startle effect, but "cancel takeoff clearance" is the wrong call for the situation.

Standard when the aircraft is already moving: "Delta 1943 stop immediately, Delta 1943 stop immediately".

The "cancel takeoff clearance" call is supposed to be only used when the aircraft has not moved yet. Like: "Delta 1943, hold position, cancel takeoff clearance, due to xxxx"

I think swearing if used correctly could highlight the rare and critical nature of the command to about immediately.

I had a sort-of hobby of learning and listening to ATC at one point. Some of these guys were scary-unintelligible . I remember this Chinese ATC at some major airport saying as fast as he possibly could “clah de leh” which was supposed to be “Clear to land”. It’s amazing the system works as well as it does.

Having accent is not the same as being "unintelligible". Do you know how to say "Clear to land" in Chinese?

The universal language of aviation isn’t Chinese.

Unintelligible: impossible to understand.

Maybe you should brush up on your own English skills?

Worth keeping in mind that recordings of ATC are taken from people running ground stations, which may not have perfect line-of-sight to the transmitter at the airport, so recordings can be lower quality and more garbled than what the pilots are actually hearing.

Totally true, although the examples I was contemplating are like in a sibling comment to yours, where even the pilots are confused. I think a lot of pilots would agree that there’s room for improvement in diction with ATC. And of course not for the sake of aesthetics or something but for safety.

I cannot find the video right now, but there was a widely watched one exactly as you describe, where the controller issued a 'cletala' several times, and it was a very American controller, I believe in California. EDIT: https://www.youtube.com/watch?v=picf7sPEhi8

ATC recording: https://youtu.be/9N1gDSZJ5s0

That looked like they were barely accelerating

> animation to scale and aircraft positions approximate

So we don't have computers anticipating the movements of airplanes, and giving warning signals if necessary?

We do but not to the extent that laypeople would think rational. Taxi instructions are verbal affairs. Hugely problematic in very busy airports. I will say that I am not sure how much automation would have helped. It does appear that this pilot had really lost situational awareness.

> It does appear that this pilot had really lost situational awareness.

Totally. The instructions were "taxi Bravo hold short of Kilo" and "cross 31L at Kilo"; read back was correct but instead of turning right at Kilo and crossing 31L, the pilot turned left, then right, and crossed 4L at Juliet.

Right, so going back to the question of automation, it seems like in principle a computer should be able to not only understand those instructions, but observe that the offending aircraft was deviating from those instructions and immediately alert.

KJFK has a system like this that uses a blend of radar and transponder multilateration to automatically signal to aircraft that they are about to enter an active runway. The pilot either did not see (for human or technical factors) or disregarded this system during the incursion.

What is lacking (to your point) is the ability to automatically compare ATC’s verbal instruction to the aircraft to its actual position.

I showed this in another thread, ForeFlight has taxi clearance in their Performance plan: https://www.youtube.com/watch?v=9p5-7jVg8fE

Very curious if/when they'll add speach to text/clearance. The syntax is fairly standard, so should be easy to parse, I'm just curious how tolerant folks would be of some % failure.

Ish. See ADS-B (https://www.faa.gov/air_traffic/technology/adsb) and TCAS (https://en.wikipedia.org/wiki/Traffic_collision_avoidance_sy...). It's mostly helpful in the air, not on the ground.

Stupid question but can't they use a system of traffic lights before crossing a runway?

As mentioned by many other commenters, this airport is equipped with exactly that.

https://www.faa.gov/air_traffic/technology/rwsl/

There is a sort of such system[0], but as others have said it’s not without limitations, especially at a large and extremely busy airport such as JFK.

https://www.faa.gov/air_traffic/technology/asde-x

Anyone wondering about map of taxi runways at JFK https://upload.wikimedia.org/wikipedia/commons/3/30/FAA_JFK_...

Once flying into NYC after passing over the end of the runway to land the plane pulled up super hard back into cursing altitude for landing. Once we leveled off, pilot came on to say, “Sorry about that folks, there was a plane taking off.” - Guess I always assumed this was a common issue.

Cursing altitude is a good description.

Ah the old KLM, Pan Am repetition was avoided. For those who don't remember: https://en.wikipedia.org/wiki/Tenerife_airport_disaster

That was very peculiar circumstances. IIRC Tiny airport with single small runway without lights that had 2 controllers staff in total landing dozens of jumbo jets diverted from an airport that had a bomb go off. And very thick fog. They had to use the same runway to taxi planes for takeoff while taxi other planes to queue up. The pilot took off without clearance while another confused pilot that was allowed on the runway was trying to find the correct exit.

This is an incredible write-up. Kudos to the journalist who wrote this piece. I wish more current events were chronicled this way.

@Dang / moderators: in case you are not already aware, in the sibling comment which is dead the username contains an inappropriate racial slur. Sorry I don't know how to better report this.

Edit: I figured it out, sorry for the noise. For anyone confused as me, you have to click the timestamp to see the `flag` link on the comment.

Email concerns to HN mods at hn@ycombinator.com.

(I've done so here.)

It's surprising that ATC works in such a human-driven manual way. Compare to train signalling, where tracks are divided into signalled sections, and a train cannot enter the next section until the section ahead is clear, with automated braking if a red signal is run. This system was developed over many tragic accidents. Even the Victorians came up with ways to minimise human error (see https://en.wikipedia.org/wiki/Token_(railway_signalling) )

One reason is air corridors aren't so well defined as railways.

What are the likely consequences of this near miss? Is someone gonna get fired?

In aviation post-event reports penalizing humans has usually the least priority, unless they intentionally violated the rules. If they did so unintentionally, or because they made a mistake, usually the entire industry gets better trainings, and/or system to prevent such. I'm generalizing here a lot.

Indeed. Punishing people for making human mistakes causes them to hide them, feel ashamed, and not highlight issues that may affect others. Aviation has fostered (very specifically) an open culture of inquisition to errors: it's assumed that if one qualified pilot made a mistake, any qualified pilot could make the same mistake under the same circumstances. If anything, you're actively encouraged to report things that are either confusing, or situations when you nearly made a mistake – the gliding club I spent a lot of time at in the past explicitly encouraged issues to be reported and put them in their monthly newsletter. Root cause analysis is a wonderful thing, and sometimes very convoluted and interesting.

I'm sure the outcome of this event will probably be a technical mitigation of some variety to attempt to stop it happening again.

Interesting that programming went in the same direction. Blameless post-mortems etc.

This move was championed in the industry by John Allspaw, then CTO of Etsy, around 2010. I am under the impression that he introduced the idea of blameless post mortems but I could be misremembering.

Opposite question: do the heroes get awards of any sort?

Sully got a bunch of awards (The commercial pilot who put that plane down safely on the river in NYC).

https://en.wikipedia.org/wiki/Sully_Sullenberger#List_of_awa...

That one I'm well aware of, but in his case part of the disaster already happened. I'm asking about pre-disaster (preventive) situations like this one.

Someone just received some very costly and professionally embarrassing training. I like to assume they'll become a better pilot for it.

No, mainly they identify the contributing factors and work to correct them. For a specific example check Air Canada 759, which nearly landed on a crowded taxiway at SFO in 2017. No one involved was fired afaik.

https://www.youtube.com/watch?v=aGQlQFn0euI

https://en.wikipedia.org/wiki/Air_Canada_Flight_759

In case anyone is curious, https://en.wikipedia.org/wiki/Air_Canada_Flight_759 is in fact interesting reading.

Although there were certainly many "systems factors" that contributed to the incident, the followup treatment of the pilots is in fact remarkable. The Wikipedia summary of the incident is "near miss attributed to pilot error". This pilot error nearly killed a thousand people. The pilots failed to report the incident (even flying the return flight the next day) and thus overwrote the cockpit voice recorder for the flight.

And despite all that, the names of the pilots are not included in the NTSB's report and Wikipedia editors/moderators think they shouldn't be included in that article. Impressive job security.

They have to call the controller and explain what went wrong. They'll then have to chat to their chief pilot over tea and biscuits minus the tea and biscuits. If they're honest, I doubt anything will come of it, even if they were violating some other regulation.

I'll be eagerly waiting for the Mentour Pilot[0] incident analysis.

[0] https://youtube.com/@MentourPilot

Also check out https://www.youtube.com/@blancolirio/videos He releases videos pretty quickly but generally tries to avoid speculation.

He’s an outstanding YouTuber.

Watching the animation at https://twitter.com/CaseWade/status/1614342894248394752, I am astonished that ground paths are routinely planned with so many conflicts, all crisscrossing frequently with so little clearance between airplanes.

I counted six other path conflicts in the space of 25 seconds, in this tiny section of the airport. With conflicts happening every few seconds, it's incredible to me that crashes don't happen more often.

Why are paths planned this way? Is capacity pressure so extreme that airplanes have to be crammed together this tightly? Is it not possible for airplanes to travel along taxi-only paths that minimize runway crossings, or wait in orderly queues and achieve nearly the same rate of takeoffs?

As we know from experience trying to use computers, humans struggle to remember a series of words, letters and numbers - like these runway instructions. When we are tired or stressed we'll make mistakes. This is true even for highly trained pilots. We need some additional safety methods like the lights. I imagine the pilot writes it down and tries to follow it. But it's a dynamic env, it might be raining, bright, or dark, planes comes and going. You might not remember the details of this runway. That's my naive view as an outsider. Eventually this system will fail (remembering and following) and lead to crash. I never thought about it but it seems inherently risky to have people "remember directions".

Layman question here, why can't airplane collisions be predicted automatically? Something like an axis aligned bounding box around each airplane and some basic velocity equations. You don't want airplanes to be too close so an approximation should suffice.

I was thinking why not at least have level crossing type warnings to stop anyone coming on to the runway when a plane has been cleared.

Like TCAS? (https://en.wikipedia.org/wiki/Traffic_collision_avoidance_sy...)

Doesn't help on the ground though.

A system for this exists, but it's new and not on many airports yet: https://www.faa.gov/air_traffic/technology/rwsl/pet/

It basically uses radar data to figure out whether it's safe to enter and safe to take-off on a runway. If it's not it will show red lights at the take-off position and entry points, pilots are trained not to cross those lights when red even if ATC says to do so.

By the time you've predicted a collision it's too late to react.

There's no advantage having a predictive tool over a binary "runway clear/not clear"

Maybe 25 years ago, I'm not sure, there was some collision at an airport and the investigators were all wondering what happened, and were trying to reconstruct which airplane was where. It turns out that there were no video cameras monitoring the taxiways and runways. I asked why not?

"Too expensive"

WAAT? Even a 7-11 had an always on camera.

"Too expensive. How would you get it to withstand the weather? How would you run power to it?"

Me: install it in the control tower, point it at the taxiways, and plug it in.

"That will never work"

Me: Sigh.

I still don't know if they have cameras monitoring the ground ops.

These days you could point a handful of cameras at the taxiways, hook it to a computer, and have a realtime display of everything on the taxiways and runways. Then, the computer could detect potential collisions and alert.

They already have a real-time display.

I can’t say for American airports but I have been involved in European air traffic control research and I can say that using algorithms isn’t very very well received by air traffic controllers.

Computers tend to do better than humans in optimal situations, but can also completely fail in other situations. One example is the sun magnetic waves disturbing the radars. For cameras I can think of many things that can fail, rabbits eating the cables, snow of the lense, or the local cloud provider having a downtime.

So because computers can fail and humans are the backup, humans must be always present and have the best situation awareness. And to have the best situation awareness, you can’t let algorithms do the work.

> For cameras I can think of many things that can fail, wabbits eating the cables, snow of the lense, or the local cloud provider having a downtime

If the people in the tower can see the operations, then a camera in the tower can see them, too. Don't need a local cloud provider.

> So because computers can fail and humans are the backup, humans must be always present and have the best situation awareness

Think of the video system as the backup. It's like the system in the car that will hit the breaks automatically if you're about to hit a wall.

BTW, I infer from your post that there STILL are no cameras pointed at the taxiways. Heck, a good chunk of homes have an always-on camera in their doorbell. This is not rocket science, and is not expensive.

Remember when that SST caught fire taking off? No video of it. The accident investigation had to do a lot of investigation to figure out when it caught fire. Because of the lack of a simple, cheap camera like you'd find in convenience store.

P.S. There are plenty of wabbits in my yard. So far, none of them have eaten through the power or phone cables. I must be just lucky :-/

Yea I agree with you. It was perhaps bad examples from me. The thing is when you do a risk analysis, digital systems have more risks than well organised and trains humans with paper and pencils.

Maybe we will eventually bring more automation in this domain.

You don't need cameras for that, they wouldn't work in lower visibility. Typically ground radar is used for this at large airports.

If the visibility is that low, wouldn't the airport be shut down?

Cameras are far cheaper than radar.

Not at all. Minimum visibility for takeoff is often 600ft and can be lower than that.

They'd be very useful for postmortems too. And all for $200.

This video does a great job illustrating the situation: https://www.youtube.com/watch?v=9N1gDSZJ5s0

Murphy's Law in action. With this many flights per day, you need tons of safety measures to ensure that mistakes like this are extremely unlikely. Like "defense in depth", you can't rely on just a few layers of countermeasures, the more the better. So yes, red lights at every intersection are good, but retrofitting planes with a gps-style map that shows exactly where to go and when to turn is even better (and of course probably insanely expensive).

The article mentions runway 4L was being used for takeoffs. In the ATC communications, you can hear them say "American 185, runway 31L at KE, line up and wait" before telling Delta 1943 to cancel their takeoff clearance. And after the near collision, ATC tells American 106 Heavy "we're departing runway 4L."

Wouldn't the line up and wait call for American 185 mean that they were departing from both 4L and 31L?

Departing 4L mean that there are no 31L full length take-off (except very very heavy aircraft). 31L at KE does not conflict with 4L, nor does it require crossing 4L.

The ATIS recording is here: https://archive.liveatc.net/kjfk/KJFK-D-ATIS-Jan-14-2023-013...

They were landing 4R and 4L, departing 4L and 31L at KE. American 106 ended up departing 31L full length since that's where they had decided to taxi to and it was probably easier to just get rid of them that way rather than have them cross 4L again to depart where everyone else was departing from.

Question

Did the B777-200 Pilots assumed the should takeoff from 4R with 2.560m length? Should be enough for a B777-200?

https://en.wikipedia.org/wiki/Boeing_777#Specifications

ATC recordings, plus a diagram more or less to scale: https://www.youtube.com/watch?v=9N1gDSZJ5s0

Interesting, because it's clear from the recording (but not the article) that the taxi instruction was read back correctly, just not followed correctly.

(At 2:48 - 2:56 if anyone's searching).

Recording of the ATC conversation: https://www.youtube.com/watch?v=9N1gDSZJ5s0

Just like in the movie 2:22... which oddly enough I was watching on Friday night.

Is there any aggregation of near misses? How often do things like this happen?

https://www.faa.gov/data_research/accident_incident

https://www.faa.gov/airports/runway_safety/statistics/

https://www.asias.faa.gov/apex/f?p=100:93:::NO:::

Sibling has the links to the authoritative data from the FAA, a search for “runway incursion” at AvHerald[0] will also yield some relevant info.

[0] https://avherald.com/ (may be hugged to death right now between this event and the turboprop crash in Nepal)

Not quite an answer to the exact question, but the FAA does publish hot spots (overview: https://www.faa.gov/airports/runway_safety/hotspots, full list: https://aeronav.faa.gov/afd/29Dec2022/All_Hotspot.PDF).

https://asrs.arc.nasa.gov/ And it’s related reports

A near miss is a collision. This was a near collision ;)

Classic George Carlin bit on this.

https://www.youtube.com/watch?v=zDKdvTecYAM

A near miss as opposed to a far miss, the type that happens when a plane in China misses one in the US

Reply on news.ycombinator.com