In this specific incident, there was a system in place called Runway Entrance Lights [0] that does serve as an automated sanity check on controllers commands. The surveillance video that is circulating shows that the system was working and indicated that the runway was not safe to enter. It's not clear yet why the truck entered the runway anyway.
I wonder if they thought that since they were responding to an emergency, and they were given clearance to cross by ATC, that that would override normal procedures. Kind of like how emergency vehicles cross a red light all the time when responding to an emergency.
It would be interesting to know whether that rule was onerous enough in practice that they had little choice but to break it in order to do their jobs effectively. They were responding to an emergency, seconds count, and they believed they had clearance from the controller.
> The surveillance video that is circulating shows that the system was working and indicated that the runway was not safe to enter.
A citation, please? The only video that I know of is [1].
[2] is my best mock up of the only video I have. I'm am not an expert, but my best read of that is that the RWSL is maybe? green to the taxiway¹ traffic, so, to me, the actual status of the RWSL at the time of the incident is "unknown"; that seems like something I should wait for the NTSB report, or at least someone with expert knowledge on. But your claims doesn't jive with the evidence I have, so that's what makes me ask for a citation.
¹but I think there are a number of problems with my own interpretation: I could be wrong about which lights are which; I am using the near-side lights, not the lights on the side the truck is entering from, and assuming them to be symmetrical (though what little I can see of the far side does seem to align with the near side); some of the lights I think are RWSLs & not RGLs look downright yellow, but that could be a property of the low quality of the video; there's the rather large problem of the plane on the runway that must then be explained.
Sorry for the late reply, and sorry for linking to reddit, but it was the first place I could find the right video. I saw this video linked at least a dozen times in the hours following the incident. I believe the clip you linked to is from the same video, but with the beginning cut off.
At approximately 1.5 seconds in my link, you can see one set of lights perpendicular to the runway turn off. I admit the the lighting/colors are not as crisp as I would like, but the lights that turn off are positionally consistent with the Runway Entrance Lights and the time at which they turn off (approximately 2 seconds before the plane enters the intersection) is also consistent with the operation of the Runway Entrance Lights system.
Furthermore, if the system was not operational it should have been NOTAMed as such, and I can find no such NOTAM so my default position is that the system was operational.
You sometimes have end around taxiways that are at one end of the runway and can be used when active. But that could be a massive diversion.
I know that Heathrow have multiple fire stations and rendezvous points for emergency services so that fire service can attend even when one runaway is closed to crossing. This could be needed to allow continued operations following a crash. It allows them to accept emergency landings more easily whilst maintaining emergency service to another active runway.
The fire station was located on the opposite side of runway 4 from the United plane. To avoid crossing the runway would mean having to travel a few extra miles around the thresholds (I assume).
I guess they could have found a route that wouldn't conflict with landing aircraft, but I doubt that's a practical option most of the time.
The REILs are part of ARFF training. Pilot training on it is also clear. The system is automated. It plots the direction and speed of anything approaching the runway and predicts a conflict. If the REILs are red it is HIGHLY likely there is a conflict that is missed by human error and you should not proceed without confirming. Don't just confirm cleared to cross, explicitly tell the controller "XYZ tower we have red runway entrance lights. Please confirm runway XX is clear".
The system is smart enough that if you get red bars to cross for an airplane departing once it passes your position the red clears because it knows the airplane is already past you. It is not dumb - it was deliberately designed to minimize false positives so everyone would trust it otherwise they might ignore it when it really counts. (AFAIK it very accurate in fact so the firetrucks weren't crossing because they distrusted the red lights).
This is just like all aviation incidents and indeed most incidents of any kind: the holes in the swiss cheese lined up.
The emergency aircraft couldn't find a free gate, creating a massive distraction for ATC, airport, et al. This is probably the primary domino that started the sequence. Had a gate been free this incident would not have happened. One big hole lined up.
Normally the aircraft would visually see the truck or the truck would visually see the airplane. But it was dark and rainy. Another hole lined up.
Everyone involved was rushing because noise abatement requires the airport to close at a certain hour. Thus everyone wanted to take-off or land before that shutdown. Another hole.
Normally the controller wouldn't issue the clearance to cross or their supervisor monitoring behind them would notice the error and override. But the controller and/or supervisor were distracted by the emergency. Another hole lined up.
The controller realized the error and issued a stop command but the fire truck proceeded anyway; they may or may not have heard the transmission. Another hole lined up.
Then someone else decided to jump on frequency during this busy time (we don't know who just yet) which may have prevented the controller's stop and/or go-around commands from being heard (another hole lined up).
The ARFF crew did not obey the REILs, accepting the clearance. Perhaps they thought the red lights were due to aircraft on short final and they still had time to cross? Perhaps it was some other misunderstanding of how that system works. Another hole lines up.
And the Air Canada jet was not paying attention to the chaos on frequency. There's a reason runway crossings are typically done on tower frequency: so aircraft can hear what is going on. But it was late at night and their brains probably didn't process what was happening. Or they were too close to touching down to have the bandwidth. Another hole lined up.
> The emergency aircraft couldn't find a free gate, creating a massive distraction for ATC, airport, et al.
Yes. And I want to add one more thing to this: the airplane with the "odour" issue was kinda ambivalent about the danger. They deemed it dangerous enough to declare an emergency, and request a gate then later ask for airstairs but not dangerous enough to pop the slides and just evacuate right there and then. I'm not saying this is wrong. Obviously they were evaluating the situation as new information was coming in. But it increased the workload of the ATC. They were trying to find a gate, and etc. If it was a clearer "mayday mayday mayday, aft cabin fire, we are evacuating" that might have been paradoxically less "work" for the ATC. Or at least more of a "practiced" scenario.
> Perhaps it was some other misunderstanding of how that system works.
Yeah. That's a big one. Total speculation but maybe they thought the airplane with the "odour" issue was keeping it red?
While it's not as sophisticated, there is a technology called Runway Entrance Lights [0] that does somewhat the same thing in the specific context of this incident. LGA is one of 20 airports around the country where this system is installed, and you can clearly see that the system was functioning if you know where to look in the surveillance video that is circulating online. For whatever reason, the truck did not respect the indicator that they should not enter the runway. So in this specific incident, short of rail-like physical limitations on movement, I think it's unlikely that any amount of additional technology would have helped.
A runway light does not physically prevent a vehicle from entering a restricted area in the same way that an interlock would. Not saying it’s practical but an interlock would have indeed prevented an accident of this type.
Yes, I get that. But an airport is not a rail network. The question is how you would actually implement physical interlocks on an airport in a way that works and is safe while controlling movement of everything from a pickup truck to an A380? It's an incredibly hard problem to solve. And keeping in mind too that the Runway Status/Entrance Lights first started development over 30 years ago and are still only deployed at 20 airports, despite being a vastly simpler system than one controlling physical barriers.
I'm curious how much of a buffer there is between the time the sensors detect the airplane and it being safe to enter the runway.
Is it definitely safe to cross the runway in a vehicle moving a normal speed up to the moment before the lights turn red? Is it safe for a little bit afterward? Or is it unsafe even a little before the lights turn red?
I work in exactly this space as a NASA contractor. I don't actually have a massive amount of insight into the FAA, but my impression is that they don't do much in the way of R&D on their own. I think (without hard numbers mind you) the vast majority of FAA R&D work starts at NASA or other government labs and gets transferred to the FAA when it gets to a sufficient level of maturity. In that context, it's even more natural for NASA to host the ASRS system.
Not GP, but I think there are a few things that could be done either through a complete re-write of the constitution or through amendments if that process somehow becomes tenable again.
1. Massively increase the size of congress. Modern technology makes this feasible in a way that it wasn't when the size was capped. More congress critters means it's harder to buy off a majority of them.
2. Re-write the first amendment to significantly limit political speech. The specifics of this are obviously very thorny, but reversing Citizens United and drastically limiting the amount of money that is spent on elections is necessary to have _any_ chance of saving the country.
1 is something I've been saying for a while. One rep for every 35k residents was the count at one point, right? I hear it's something like one for every 800k now. And constituency shouldn't be based on geography; if the most important issue to me is whatever, I should be able to fill my ranked-choice ballot with candidates that support Whatever. We can work out the mechanics, but the point would be to have a legislative body where each rep had 35k distinct names behind them.
2 is dicey and I would like to try campaign finance reform first.
I don't want to throw everything out because that's how you get slavery and The Handmaid's Tale. At the same time, I'll gladly acknowledge that a lot of our institutions were rotten from the founding and to their core, and their dismantling maybe not necessary but certainly suitable for a reborn America that leaves much of its baggage behind.
2 is campaign finance reform. The only meaningful campaign finance reform is going to come with limits on political speech. Otherwise you just get the same amount of spend with even more of it being funneled through PACs.
Campaign finance reform gets rid of private financing of PACs and Super PACS altogether. You might call that limiting speech, and I guess it is, in a way, but it's not a restriction for its own sake, but rather to emphasize that actual main reform: public financing (and necessarily limited).
> 1. Massively increase the size of congress. Modern technology makes this feasible in a way that it wasn't when the size was capped. More congress critters means it's harder to buy off a majority of them.
I agree with 1. 2 is more of a reform of current law rather than an amendment. I would like to see the 17th amendment repealed also. Capping representatives greatly skewed the distribution of power in congress. The balance of congressional power was harmed equally by making senators popularly elected instead of appointed by state legislatures to represent the state government.
Yes, I'm fully aware. And it is emphatically irrelevant. It's kind of ridiculous to suggest the original motivations for the rule somehow render the associated risks on people's safety, lives, and properties permanently ineligible for consideration.
Fine by me. I don't particularly like Python, but it's the defacto standard in my field so I have to use it (admittedly this is an improvement over a decade ago, when MATLAB was the defacto standard). I don't care about preserving the spirit of Python, I just care that the thing that bears the name Python meets my needs.
> Most engineers never get to choose the programming language used for 90% of their professional projects.
If it was up to me, there are plenty of languages to choose from that meet my technical needs just fine, but the political friction of getting all of my colleagues (most of whom are not software engineers at all) to use my language of choice is entirely insurmountable. Therefore, I have a vested interested in seeing practical changes to Python. The existence or invention of other languages is irrelevant.
Couldn't disagree more. To the extent building a homebrew CPU is interesting at all, for me it's _only_ making it actually work despite all of the real world hiccups that make it interesting. Designing it in the simulator is "easy".
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