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

211–220 of 372 posts

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

#211

Post by jquery »

astrange wrote: post #185
cguess wrote: post #142

Earlier quoted context omitted.

I'm guessing you've never worked in system-critical infrastructure? Airplanes are another level up from that. I'm not the one saying this, the FAA and NTSB are. Nothing is allowed to go wrong, ever.

I've been stuck at SFO for hours at least once a year because our flight had some mechanical issue. (Always on a Delta flight to ATL or MSP, don't know why.) They did fix it and then eventually we took off. In a way that's "not going wrong". On the other hand, they didn't cancel it and send the plane to be disassembled for failure analysis. That'd certainly be safer.

The fact they didn’t take off with the mechanical issue should be a point in their favor, not against them.

More accurately though, safety critical things are not allowed to go wrong. If they do, they get investigated. What is and isn’t deemed safety critical is a document written in blood, unfortunately.

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

#213

Post by techdragon »

ip26 wrote: post #171
techdragon wrote: post #129

Earlier quoted context omitted.

Maximum breaking, is powerful stuff… Real red hot metal and tolerances engineering stuff. You have to be able to stop the airplane at it’s maximum take off weight at the maximum takeoff ground speed (got to account for tail winds) within the acceptable safety stopping distance on the runway, and they have to sit there after this without any help for several minutes to represent the time it can take to scramble ground…

The classic: https://m.youtube.com/watch?v=qew09gao3S8 In short, the whole brake assembly catches fire- and continues to operate.

Definitely a much better view of the brake assembly and the extreme forces they deal with. I’d forgotten how much the sound reminds me of a sort of bad off key imitation of the “Deep Note” Dolby THX intro sound. As the rotation speed slows it pitches down the frequency scale into more audible tones and sounds slightly louder as the microphone picks it up better and then it fades out towards the end.

I do think it even though it’s a better brake mechanism video it’s not quite as visually impressive as watching a 747-8 just about to nose up suddenly nosing down as it slams on the brakes and they come to a stop in a dissipating cloud of smoking revealing the red hot brakes glowing in the wheels.

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

#214

Post by BHSPitMonkey »

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.

That animation from FR24 is interpolating the motion between sparsely-updated position/speed/heading info, so the changes will appear more sudden than they actually are.

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

#215

Post by mkl95 »

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.

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

#216

Post by refurb »

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…

Newark is super congested too.

I remember flying from Michigan to Newark once and the ticket said “2 hours 45min” and I thought that was nuts, it’s like an hour flight.

Turns out they tack on an hour leaving and coming for taxing and waiting in line.

At least that’s how it was a decade ago.

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

#217

Post by quickthrower2 »

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.

I was thinking why not at least have level crossing type warnings to stop anyone coming on to the runway when a plane has been cleared.

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

#218

Post by kevinventullo »

asciimike wrote: post #40
sklargh wrote: post #24

Earlier quoted context omitted.

We do but not to the extent that laypeople would think rational. Taxi instructions are verbal affairs. Hugely problematic in very busy airports. I will say that I am not sure how much automation would have helped. It does appear that this pilot had really lost situational awareness.

> It does appear that this pilot had really lost situational awareness. Totally. The instructions were "taxi Bravo hold short of Kilo" and "cross 31L at Kilo"; read back was correct but instead of turning right at Kilo and crossing 31L, the pilot turned left, then right, and crossed 4L at Juliet.

Right, so going back to the question of automation, it seems like in principle a computer should be able to not only understand those instructions, but observe that the offending aircraft was deviating from those instructions and immediately alert.

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

#219

Post by c2xlZXB5 »

The article mentions runway 4L was being used for takeoffs. In the ATC communications, you can hear them say "American 185, runway 31L at KE, line up and wait" before telling Delta 1943 to cancel their takeoff clearance. And after the near collision, ATC tells American 106 Heavy "we're departing runway 4L."

Wouldn't the line up and wait call for American 185 mean that they were departing from both 4L and 31L?

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

#220

Post by quickthrower2 »

farseer wrote: post #212

Ah the old KLM, Pan Am repetition was avoided. For those who don't remember: https://en.wikipedia.org/wiki/Tenerife_airport_disaster

That was very peculiar circumstances. IIRC Tiny airport with single small runway without lights that had 2 controllers staff in total landing dozens of jumbo jets diverted from an airport that had a bomb go off. And very thick fog. They had to use the same runway to taxi planes for takeoff while taxi other planes to queue up. The pilot took off without clearance while another confused pilot that was allowed on the runway was trying to find the correct exit.
Post reply on HN