Earlier quoted context omitted.
My jaw kept dropping with each new bullet point.
Same, is aviation technology really this primitive?
Airline messaging is wild, this blog from 2010 knows what’s what: https://cos.livejournal.com/79455.html
UK air traffic control meltdown
291–300 of 459 posts
Re: UK air traffic control meltdown
#292So they forgot to "geographically disparate" fence their queries. Having built a flight navigation system before, I know this bug. I've seen this bug. I've followed the spec to include a geofence to avoid this bug.
Just curios, what language was used to develop?
Re: UK air traffic control meltdown
#293And why could the system not put the failed flight plan in a queue for human review and just keep on working for the rest of the flights? I think the lack of that “feature” is what I find so boggling.
Because the code classified it as a "this should never happen!" error, and then it happened. The code didn't classify it as a "flight plan has bad data" error or a "flight plan data is OK but we don't support it yet" error. If a "this should never happen!" error occurs, then you don't know what's wrong with the system or how bad or far-reaching the effects are. Maybe it's like what happened here and you could have co…
That's true, but then, why did engineers try to restart the system several times if they had no clue what was happening, and restarting it could have been dangerous?
Re: UK air traffic control meltdown
#294Earlier 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
I'm trying to imagine someone ensuring differentiation between minimums.unsettled.depends (Idaho), minimums.unsettled.depend (Alaska), minimums.unsettles.depend (Spain), and minimum.unsettles.depend (Russia) while typing them in on a t-9 style keypad with a 7 figure display in turbulence.
Re: UK air traffic control meltdown
#295Earlier quoted context omitted.
Yes. It would cascade into: Changes in how ATCs operate Changes in how pilots operate Changes in how airplanes receive these instructions (including the flight software itself, safety systems, etc.) Changes in how airplanes are tested Changes in how pilots are trained Etc. In this case, the refactoring requires changes to hardware, software, training, manufacturing, and humans.
Pretty sure that is still not the meaning of refactoring. As I understand it refactoring should mean no changes to the external interface but changes to how it is implemented internally.
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Re: UK air traffic control meltdown
#296Earlier quoted context omitted.
Why on earth do they not have GUIDs for these navigation points if the names are not globally unique and inter-region routes are commonplace?
What three words would be a better solution than a guid, as transmittable over radio.
I always love it when someone helicopters in to a complex, long-established system and, without even attempting to understand the requirements, constraints or history, knows this thing they read on a blog one time would fix all the problems thousands of work-years have failed to address.
Re: UK air traffic control meltdown
#297Earlier 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
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.
Re: UK air traffic control meltdown
#298Earlier quoted context omitted.
> "we have an aircraft en route to enter UK airspace and we don't know when or where - stop planning more flights until we know where that plane is". Flight plans don't tell where the plane is. Where is this assumption coming from?
Flight plans do inform ATC where and when a plane is expected to enter their FIR though, no?
Only theoretically. In practice the only thing that usually matches is from which other ATC unit the plane is coming. But it could be on a different route and will almost always be at a different time due to operational variation.
That doesn't matter, because the previous unit actively hands the plane over. You don't need the flight plan for that.
What does matter is knowing what the plane is planning to do inside your airspace. That's why they're so interested in the UK part of the flight plan. Because if you don't give any other instructions, the plane will follow the filed routing. Making turns on its own, because the departing ATC unit cleared it for that route.
Re: UK air traffic control meltdown
#299Earlier quoted context omitted.
> the phenomenon has even got a name - "poison flight plan". Maybe, but it must not be a common phrase because your comment is the first result when I search for it. And it is also mentioned in this article: http://www.aero-news.net/subsite.cfm?do=main.textpost&id=ce2... And that's about it? Do you have any other sources?
I think that term was invented four days ago by that article writer. There are four other occurrances before then and they're about PS2 games.
Ironically the term about name clashes has a name clash!
Re: UK air traffic control meltdown
#300Great post. This part goes too far, I think: > Human lives were kept safe at all times > The consequence of all this was not that any human lives were put in danger, .. When you're arguing that cancelling 2000 flights cost £100M and that no human danger was incurred, something should feel off. That might be around 600k humans who weren't able to be where they felt they needed to be. Did they have somewhere safe to sl…
I mean it could have also saved lives by that logic. Did someone missing their flight mean they also missed a terrible pileup on the roadways after landing? We can imagine pretty much any scenario here.
I agree with you that we don't know! But my thesis is that we should still do our best, when considering how much risk the systems we maintain should be willing to keep operating through.