Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Friday night’s near-disaster at JFK airport

viewfromthewing.com

Post reply on HN
Print view View original

111–120 of 372 posts

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

#111

Post by seo-speedwagon »

Symbiote wrote: post #67
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.

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.

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

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

#112

Post by polishdude20 »

lelandfe wrote: post #98
Symbiote wrote: post #67

Earlier quoted context omitted.

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.

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

#113

Post by thecosmicfrog »

plusminusplus wrote: post #97
m_a_g wrote: post #13

> 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.

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

#114

Post by ajross »

jamiek88 wrote: post #103
ajross wrote: post #91

Earlier quoted context omitted.

> 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 cle…

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.

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

#115

Post by mgsouth »

lelandfe wrote: post #98
Symbiote wrote: post #67

Earlier quoted context omitted.

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.

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...

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

#116

Post by CoastalCoder »

tempestn wrote: post #108
BoorishBears wrote: post #95

Earlier quoted context omitted.

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.)

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

#117

Post by fragmede »

Dalewyn wrote: post #60
KRAKRISMOTT wrote: post #52

Earlier quoted context omitted.

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.

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.

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

#118

Post by kylehotchkiss »

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

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

#119

Post by CPLX »

polishdude20 wrote: post #112
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.

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.

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

#120

Post by michaericalribo »

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…

Whoa fascinating. What makes it necessary to commit after V1?
Post reply on HN