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Comment by twalichiewicz | Hacker News Reader

Was curious if ground vehicles at airports also use transponders to communicate position to the radio tower, and it turns out the FAA put out a report last year on potential solutions to avoid this exact situation:

https://www.faa.gov/airports/airport_safety/certalerts/part_...

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Many airports have ADS-B transponders in their ground vehicles. You can see them on flightradar or adsbexchange.

> Was curious if ground vehicles at airports also use transponders to communicate position […]

They do at CYYZ (Toronto Pearson):

* https://www.flightradar24.com/43.68,-79.63/13 (zoomed in)

* https://www.flightradar24.com/airport/yyz

Also at CYUL (Montreal Trudeau) and CYVR (Vancouver International).

https://www.youtube.com/watch?v=c8Kqg6sokz4

Truck declared it was crossing. ATC told it to stop. Truck didn't stop.

This wasn't a communication issue.

He asked Frontier 4195 to stop. By the time he asked truck 1 to stop they were entering the runway.

Audio in this video is cut, with parts of the recording omitted, see here for the full recording: https://youtu.be/Pbm-QJAAzNY?si=4Kkd8t8VEAsgHmJv&t=149

Timestamps from the video:

2:46 Truck requests crossing

2:51 ATC allows it to cross

2:53 Truck confirms

2:58 ATC: "Frontier 4195 stop there please"

3:02 ATC: "stop stop stop stop truck one stop stop stop"

3:15 ATC: "tower, truck one, stop, ..."

Crash probably a couple seconds later, wouldn't rely on the video for the exact timing.

So it seems that ATC made an error by allowing the truck to cross, and then the order to stop wasn't communicated clearly enough. I wouldn't place much blame on the truck.

Edit: Looking at some other videos with that audio, I'm also not sure if the video I linked represents the time between communications correctly, transmission at 3:15 may have been right after the one at 3:02. Anyway, the best thing is to wait for the investigation.

Or just do like the rest of the world. No anticipated clearences to land, you only ever get a clerance when the runway is empty and yours.

Yeah that gut wrenched ATC had to stay on point and ensure the next plane to land did a go around. Scary stuff.

Us lot have more people doing SRE ensuring p99 10ms for something frankly way less important. It is a nuts world.

I think this is a good idea.

The only negative I can think of is that it will generally involve accepting and responding to clearances on short final. I think adding more tasks to that critical stage of flight probably increases danger a little. Especially for low time student pilots like myself. That's particularly relevant in the U.S. because we have a higher percentage of student and private pilots than most of the world.

Overall, though, I'm fully convinced this would be safer.

Even without anticipated clearance to land you have to define what "the runway is empty and yours" means.

Ground vehicles with transponders: https://adsb.exposed/?dataset=Planes&zoom=7&lat=42.1262&lng=...

LaGuardia has that system, it still failed to prevent this

Transponder doesn't alter the laws of physics for the landing plane you just cut off. I guess it gives ATC a ~5sec jump on telling some other flight to go around.

I'd bet a lot of money that however the system is implemented the police and fire get special treatment when it comes to process (i.e. asking permission before they go somewhere planes might be) and that is part of what lead to this.

> I'd bet a lot of money that however the system is implemented the police and fire get special treatment when it comes to process (i.e. asking permission before they go somewhere planes might be) and that is part of what lead to this.

I highly doubt that any system would intentionally give ground vehicles of any kind special treatment on an active runway.

The trajectory of the plane is obvious enough that it should be able to predict where it will likely be in 30 seconds or a minute. You can't cheat physics, if it is going down in direction of runway, it is landing or at worst will do go-around, so the services should be alterted runway is no-go automatically

It was night time so idk how obvious it would be that a plane is approaching when you're in a firetruck and probably have a million others things going on that all necessitate your attention as well.

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