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SFO near miss might have triggered aviation disaster

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Re: SFO near miss might have triggered aviation disaster

#271

Post by dx034 »

mckoss wrote: post #240
dx034 wrote: post #120

Earlier quoted context omitted.

It's likely that the controller would've seen it as well after the Air Canada pilot indicated that he saw planes on what he believed was the runway. Even if not, the pilot would've probably aborted the landing since he saw the other aircrafts. So it was certainly a dangerous situation but I doubt that a crash would've happened without that pilot's comment (it was certainly helpful though).

Controllers in the tower do not have a good visual perspective to see runway alignment. I don't think they would have caught this. At night, there are many visual cues to see the runway environment - it sounds to me like this complacent pilot ignored many red flags and was about to drive his plane on top of those on the taxiway. A big heavy airliner can't just stop its decent instantly; it's a good thing that pilot o…

But they have radar and usually extended centerlines. That should've been clearly visible for him on the screen.

Re: SFO near miss might have triggered aviation disaster

#272

Post by Piskvorrr »

tialaramex wrote: post #230
Piskvorrr wrote: post #216

Earlier quoted context omitted.

And then your Cat-IIIc equipment is offline for whatever reason, and nobody had landed a plane by hand for years at that point. Now what? (In other words, automation has its own set of failure modes)

Right, but a problem with humans is that they tend to seriously over-estimate their capability. So we need to be statistics led on this Given the choice between "One time in a million a human flies the aeroplane into the ground and everybody dies" and "One time in 10 million the computer flies the aeroplane into the ground and everybody dies" we ought to be hard-headed and take the ten times fewer deaths, but we pref…

We are not in disagreement. My reply was to "why not automate everything?" and indeed the answer is "because sometimes humans are better," not "do not automate anything" :)

Re: SFO near miss might have triggered aviation disaster

#273

Post by Piskvorrr »

wfunction wrote: post #227
Piskvorrr wrote: post #207

Earlier quoted context omitted.

Okay, correction. Airplanes don't have GPS systems that work better at the level of reliability required . "It works most of the time, except it sometimes doesn't" might be sufficient when you can stop at the roadside, but doesn't quite cut it in the air.

Okay so let me get this straight: you're telling me that passenger airplanes currently fly by dead reckoning or stellar navigation or ground-based triangulation or something else? When a pilot doesn't know where he is, he doesn't have any kind of certified GPS-based system handy to tell him? And moreover, even beyond GPS: how the hell can a plane's navigation system be capable of (and certified for!) landing the mons…

Seriously? From here, it looks as if you're doing your best in refusing to understand. Here's a hint: context. If you're en route, even an approximate position within hundreds of feet is great for navigation; please stow your straw men back where you found them.

In this case, the issue is with landing, where you need a precise position; "probably tens of feet, when it works" is exactly the sort of accuracy that's not good enough. As for "know where it is and land" - that's already there, is called Precision ILS, and uses no elements of GPS whatsoever.

Re: SFO near miss might have triggered aviation disaster

#274

Post by adrianN »

dmitrygr wrote: post #64
desdiv wrote: post #43

Earlier quoted context omitted.

.

It is a very Silicon Valley thing to assume that everyone else is an idiot and needs to be disrupted, with not a thought given as to why things are the way they are. Sort of funny to watch it from the side I assure you that there is a reason AM is used. The reason is that in the case that two stations are transmitting, everyone will be aware of it and the stronger signal may be heard. This is not something that FM ca…

Digital only require better signal if you want high data rates. With analog signal the human has to do the error correction, i.e. extract the signal from the snowy picture. Digital signals can use error correcting codes to get the same result. The more bits you have for error correction, the better your recovery can be.

Re: SFO near miss might have triggered aviation disaster

#275

Post by pvg »

watson wrote: post #176

English is not my native language, but shouldn't the headline have read "SFO near miss would have triggered aviation disaster"? "Might" seems to indicate that something else happened afterwards as a possible result of the near miss

"Might" seems to indicate that something else happened afterwards as a possible result of the near miss

In this case it doesn't, the headline can be interpreted in slightly different ways but is not wrong (or really that ambiguous) as written. Standard headline-speak for 'something happened that was a possible cause for something else that also happened' is 'may have caused' like here:

https://www.nytimes.com/2017/06/23/science/bright-nights-noc...

Re: SFO near miss might have triggered aviation disaster

#276

Post by dsfyu404ed »

luca_ing wrote: post #223
wfunction wrote: post #66

Earlier quoted context omitted.

Fantastic explanation, and the question on my mind the entire time is "but why??"! Surely the copilot can look at a map (when I say map I don't mean a piece of paper -- I mean a digital one with GPS and everything) and see their trajectory while the pilot is landing, right? Like I'm imagining there should be something on the plane that shows them their trajectory and the runway information. If there is, why isn't it…

> Surely the copilot can look at a map (when I say map I don't mean a piece of paper -- I mean a digital one with GPS and everything) and see their trajectory while the pilot is landing, right? It's not like the pilot doesn't know there is a parallel taxiway. Of course there is. They would be (subconsciously anyway) looking for it to complete their mental map. It just went wrong in this case. You wouldn't even have n…

x2. This is redundancy in action.

Re: SFO near miss might have triggered aviation disaster

#277

Post by Piskvorrr »

amelius wrote: post #217
URSpider94 wrote: post #162

Earlier quoted context omitted.

I don't think a map or chart would necessarily solve the problem. The taxiway runs parallel to the runway, in the same direction, is the same length, and is similar in width. Similar to how a map or GPS won't stop you from turning down the wrong way on a divided highway. Or how there have been many cases of people following GPS and turning onto railroad tracks that parallel roads. https://www.google.com/search?q=driv…

When the GPS in my car shows two lanes, it clearly marks whether I should take the left or right one.

...but it sometimes detects your position as being in the other lane than where you actually are (or even a block away).

Re: SFO near miss might have triggered aviation disaster

#278

Post by vacri »

briandear wrote: post #256
vacri wrote: post #171

Earlier quoted context omitted.

So many people use 'begs the question' as 'raises the question' now that it's a valid meaning for the phrase. EDIT: To the downvoters: I don't think you understand how human language works.

Does not something wrong enough times doesn’t make it correct. For example using “because” without a preposition doesn’t become correct just because Buzzfeed makes it popular. People make grammar/useage mistakes not because they consciously want to change the language but because they don’t know any differently. It’s quite different than how slang enters a language. Begs vs. raises the question isn’t some kind of col…

People don't have to consciously want to change the language for it to change. It's not like the differences between modern English and Victorian-era English are all because someone willed it. Usage dictates meaning, and I'd say the general public uses 'begs the question' as 'raises the question', whereas only people interested in philosophy use it as 'presume the answer' - essentially the latter version has become a sort of jargon regarding fallacies.

It's like the word 'irregardless'. As much as 'it isn't a word', it clearly is, because you know what is meant when it's said, and plenty of people say it.

Re: SFO near miss might have triggered aviation disaster

#279

Post by wfunction »

Piskvorrr wrote: post #273
wfunction wrote: post #227

Earlier quoted context omitted.

Okay so let me get this straight: you're telling me that passenger airplanes currently fly by dead reckoning or stellar navigation or ground-based triangulation or something else? When a pilot doesn't know where he is, he doesn't have any kind of certified GPS-based system handy to tell him? And moreover, even beyond GPS: how the hell can a plane's navigation system be capable of (and certified for!) landing the mons…

Seriously? From here, it looks as if you're doing your best in refusing to understand. Here's a hint: context . If you're en route, even an approximate position within hundreds of feet is great for navigation; please stow your straw men back where you found them. In this case, the issue is with landing , where you need a precise position; "probably tens of feet, when it works" is exactly the sort of accuracy that's n…

The issue is you're treating this as though (1) cruising can be done on autopilot via GPS because it doesn't need much accuracy, (2) landing can also be done on autopilot because we have more accurate systems, but (3) the transition between the two requires manual intervention because the plane can't reliably locate itself accurately enough to get in the right position for landing systems to take over.

But that simply doesn't seem to be the case (in normal weather, which we had here). See my reply to a sibling comment here for a link. It seems that in normal conditions planes are capable of doing it all in one go, which means they are capable of accurately and reliably locating themselves. Nobody is expecting these to work in extreme conditions like bad weather or bird collisions, but in those conditions autopilot can and does already get disengaged (whether automatically or manually), and this could be done the same way. It's not like we forbid autopilot entirely because it isn't 100% perfect, so why not apply the same standards here?

Re: SFO near miss might have triggered aviation disaster

#280

Post by wbl »

luca_ing wrote: post #223
wfunction wrote: post #66

Earlier quoted context omitted.

Fantastic explanation, and the question on my mind the entire time is "but why??"! Surely the copilot can look at a map (when I say map I don't mean a piece of paper -- I mean a digital one with GPS and everything) and see their trajectory while the pilot is landing, right? Like I'm imagining there should be something on the plane that shows them their trajectory and the runway information. If there is, why isn't it…

> Surely the copilot can look at a map (when I say map I don't mean a piece of paper -- I mean a digital one with GPS and everything) and see their trajectory while the pilot is landing, right? It's not like the pilot doesn't know there is a parallel taxiway. Of course there is. They would be (subconsciously anyway) looking for it to complete their mental map. It just went wrong in this case. You wouldn't even have n…

He did notice and asked the controller if he really was clear, who then gave the goaround. At least that's my read of the story.
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