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

UK air traffic control meltdown

jameshaydon.github.io

Post reply on HN
Print view View original

451–459 of 459 posts

Re: UK air traffic control meltdown

#451

Post by seabass-labrax »

epolanski wrote: post #442
seabass-labrax wrote: post #436

Earlier quoted context omitted.

Indeed, but the set of aerodromes that are large enough to have a tower controller but not large enough to have their own radar surveillance is shrinking all the time. Radar is getting cheaper and what with ADS-C and TA/RA, a big reason to have ATC even without radar is vanishing (namely that of preventing collisions close to the airport). Oceanic control is probably the closest you can get nowadays to routine ATC wi…

I think an island in the middle of the Atlantic that is mostly used for refueling is exactly that kind of airport. Can't remember the name but I'm quite sure it belongs to Portugal.

Was it part of the Azores?

Re: UK air traffic control meltdown

#452

Post by jwr »

cutemonster wrote: post #433
jefftk wrote: post #426

Earlier quoted context omitted.

> if one fails, he will have no idea which one is correct Depends how it fails! For example, say, when you change direction one turns and the other doesn't.

Couldn't he bring his own 3rd? Compasses aren't heavy?

…or a 4th and a 5th, and have voting rounds — an idea explored by Stanisław Lem in "Golem XIV", where a parliament of machines voted :-)

Re: UK air traffic control meltdown

#453

Post by avianlyric »

zarzavat wrote: post #273
avianlyric wrote: post #203

Earlier quoted context omitted.

How exactly would you do that? It’s impossible to map from a dataset of non-unique identifiers to unique identifiers without additional data and heuristics. The mapping is ambiguous by definition. The underlying flight plan standard were all created in an era of low memory machines, and when humans were expected to directly interpret data exactly as the programs represented it internally (because serialisation and de…

Couldn’t you use the surrounding points? Each point is surrounded by a set of nearby points. You can prepare a map of pairs of points into unique ids beforehand, then have a step that takes (before, current, after) for each point in the flight plan and finds the ID of current.

Yes you can, but that would be using

> additional data and heuristics

Directly mapping is impossible, so you cant just do a dumb ID-at-time pre-processing step (which is what your comment seems to suggest). You need a more complex pre-processing step that’s capable of understanding the surrounding context the identifier is being used in. A major issue with the flight planing system (as highlighted in the article) is that they attempted to do this heuristic mapping as part of their core processing step, and just assumed the ID wouldn’t be too ambiguous, and certainly wouldn’t repeat.

Re: UK air traffic control meltdown

#454

Post by amatecha »

DyslexicAtheist wrote: post #278
nwallin wrote: post #237

Earlier quoted context omitted.

1. Pilots occasionally have to fat finger them into ruggedized I/O devices and read them off to ATC over radios. 2. These are defined by the various regional aviation authorities. The US FAA will define one list, (and they'll be unique in the US) the EU will have one, (EASA?) etc. The AA965 crash (1995-12-20) was due to an aliased waypoint name. Colombia had two waypoints with the same name within 150 nautical miles…

> Pilots occasionally have to fat finger them into ruggedized I/O devices you're saying what-3-words (W3W) is unsuitable for safety critical applications ? /s

Many authorities on the subject warn against using W3W for safety-critical applications.[0][1][2]

Personally I could imagine that Maidenhead Locator System[3] may be more useful. It's just 4-12 chars (depending on what degree of accuracy you need)

[0] https://www.summerlandreview.com/news/bc-search-and-rescue-g...

[1] https://globalnews.ca/news/8258671/north-shore-rescue-what3w...

[2] https://www.squamishchief.com/local-news/squamish-search-and...

[3] https://en.wikipedia.org/wiki/Maidenhead_Locator_System

Re: UK air traffic control meltdown

#455

Post by railmeat »

robocat wrote: post #367
pmarreck wrote: post #364

Earlier quoted context omitted.

There are a number of word lists whose words were picked due to their beneficial properties given the use-case of possibly needing to be understood verbally over unclear connections. The NATO phonetic alphabet, and PGP word lists come to mind: https://en.wikipedia.org/wiki/PGP_word_list I'm particularly a fan of the PGP word list (it would definitely require more than 3 words for this purpose, though) because it has…

> I'm particularly a fan of the PGP word list As a New Zealander, the PGP list is unfriendly because there are plenty of words that are hard to spell, or are too US centric. dogsled (contains silent d, and sleigh might be a British spelling) Galveston (I've never heard of the place) Geiger (easy to type i before e - unobvious) Wichita (I would have guessed the spelling began with which or witch) And why did the desig…

I have been to Galveston and I can assure you that you have not missed anything. There is no good reason to visit or know anything about it.

Making a word list that could work well for speakers different English dialects and for speakers of English as a second language sounds really hard. Has such a list as been made?

Probably it is too hard so we will continue to ignore the problem.

Re: UK air traffic control meltdown

#456

Post by mavhc »

pmarreck wrote: post #364
retrocryptid wrote: post #297

Earlier quoted context omitted.

Something like what3words might be useful, but what3words itself doesn't have enough "auditory distance" between words. (i.e. - there are some/many words used by what3words that sound similar enough to be indistinguishable over an audio channel with noise.) Something like FixPhrase seems better for use over radio.

There are a number of word lists whose words were picked due to their beneficial properties given the use-case of possibly needing to be understood verbally over unclear connections. The NATO phonetic alphabet, and PGP word lists come to mind: https://en.wikipedia.org/wiki/PGP_word_list I'm particularly a fan of the PGP word list (it would definitely require more than 3 words for this purpose, though) because it has…

> It sounds like the w3w folks did not do any such thing

They were too busy spending money on marketing, it's not like every news organisation ran a story about it by accident

Re: UK air traffic control meltdown

#457

Post by ric2b »

Neil44 wrote: post #393
fennecfoxy wrote: post #390

"UK air traffic control: inquiry into whether French error caused failure" Of course bloody not. How is it a French airline's fault when it's a UK system? Systems like this should be foolproof with redundancies. If one entry is bad reject it and carry on, even.

Well if you want to get all nationalistic, the software was Austrian.

But built to UK spec

Re: UK air traffic control meltdown

#458

Post by fennecfoxy »

Neil44 wrote: post #393
fennecfoxy wrote: post #390

"UK air traffic control: inquiry into whether French error caused failure" Of course bloody not. How is it a French airline's fault when it's a UK system? Systems like this should be foolproof with redundancies. If one entry is bad reject it and carry on, even.

Well if you want to get all nationalistic, the software was Austrian.

It's not nationalism just because I'm defending one country in favour of another.

I'm not French and nor am I British. I feel neutral about both of them though I do live in the UK.

It's just logic, not nationalism. :/

Re: UK air traffic control meltdown

#459

Post by fransje26 »

WalterBright wrote: post #443
fransje26 wrote: post #410

Earlier quoted context omitted.

As as side note, too bad they knowingly didn't reuse such an approach for the MAX..

The MAX system relied on the pilot remembering the stab trim cutoff switch and what it was for.

Even though the trim cutoff switch didn't work as it used to do on the previous generation of 737s, and the pilots were not notified about the change.
Post reply on HN