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Friday night’s near-disaster at JFK airport

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Re: Friday night’s near-disaster at JFK airport

#251

Post by boredhedgehog »

giantg2 wrote: post #127
hn_user2 wrote: post #43

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 cr…

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

Where was the miscommunication? The pilot readback was correct.

Re: Friday night’s near-disaster at JFK airport

#252

Post by rnk »

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".

Re: Friday night’s near-disaster at JFK airport

#254

Post by a9h74j »

akira2501 wrote: post #247
julian_sark wrote: post #231

Earlier quoted context omitted.

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 ...

> 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 o…

> 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?

Re: Friday night’s near-disaster at JFK airport

#255

Post by paganel »

Waterluvian wrote: post #75
christophilus wrote: post #48

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.

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 f…

> 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.

Re: Friday night’s near-disaster at JFK airport

#256

Post by kube-system »

landemva wrote: post #243
kube-system wrote: post #199

Earlier quoted context omitted.

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.

Re: Friday night’s near-disaster at JFK airport

#257

Post by boredhedgehog »

mkl95 wrote: post #215

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.

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

Doesn't help on the ground though.

Re: Friday night’s near-disaster at JFK airport

#258

Post by speedgoose »

WalterBright wrote: post #228
WalterBright wrote: post #227

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 yo…

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.

Re: Friday night’s near-disaster at JFK airport

#259

Post by dmurray »

landemva wrote: post #243
kube-system wrote: post #199

Earlier quoted context omitted.

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'.

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

Re: Friday night’s near-disaster at JFK airport

#260

Post by CaptainZapp »

boredhedgehog wrote: post #251
giantg2 wrote: post #127

Earlier quoted context omitted.

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

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.

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