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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

#131

Post by cguess »

doubleunplussed wrote: post #122
jamiek88 wrote: post #103

Earlier quoted context omitted.

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…’

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…

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.

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

#132

Post by sokoloff »

CoastalCoder wrote: post #116
tempestn wrote: post #108

Earlier quoted context omitted.

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…

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

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

#133

Post by lelandfe »

mgsouth wrote: post #115
lelandfe wrote: post #98

Earlier quoted context omitted.

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.

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 i…

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.

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

#134

Post by cguess »

kylehotchkiss wrote: post #118

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…

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

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

#135

Post by zmgsabst »

jahewson wrote: post #83
ars wrote: post #79

Earlier quoted context omitted.

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.

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

#136

Post by jupp0r »

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…

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.

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

#137

Post by zmgsabst »

cguess wrote: post #131
doubleunplussed wrote: post #122

Earlier quoted context omitted.

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…

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 s…

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.

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

#138

Post by techdragon »

CPLX wrote: post #119
polishdude20 wrote: post #112

Earlier quoted context omitted.

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.

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

#139

Post by exmadscientist »

cguess wrote: post #131
doubleunplussed wrote: post #122

Earlier quoted context omitted.

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…

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 s…

> 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.

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

#140

Post by Retric »

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.

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