7 ms·
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?
by sam0x17 3y ago
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?
- amoerie 3y agoLong story: because changing identifiers is a considerable refactoring, and it takes coordination with multiple worldwide distributed partners to transition safely from the old to the new system, all to avoid a hypothetical issue some software engineer came up with Short story: money. It costs money to do things well.
- ftxbro 3y ago> Long story: because changing identifiers is a considerable refactoring is this what refactoring means
- NBJack 3y agoYes. 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.
- ftxbro 3y agodoes refactoring mean literally any non-local change even just like changing a variable name, or does it usually mean some kind of structural or architectural non-local change
- deadfish 3y agoPretty 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.
- LelouBil 3y agoYou could see it as the whole international flight system being refactored, consumers will still use planes like before
- deleted 3y ago[deleted]
- NBJack 3y agoWe can pontificate on how to define the scope of a system here. I will only state that, from the perspective of a consumer, you could consider this a Service on which the interface of find flight, book flight, etc. would appear to be the same while the connections internal to each of the above modules would have to account for the change. Functionally, I suppose it's the equivalent of upgrading an ID field that was originally declared as an unsigned 32 bit integer to a wider 64 bit representation. We may not be changing anything fundametal in the functionality, but every boundary interface, protocol, and storage mechanism must now suffer through a potentially painful modification.
- Topgamer7 3y agoI would guess because humans have to read this and ascertain meaning from it. Not everyone is a technical resource.
- f1shy 3y agoThe names have to be entered manually by pilots, if e.g. they change the route. They have to be transmitted over the air by humans. So they must be short ans simple.
- zarzavat 3y agoYes but shouldn’t one step of the code be to translate these non-unique human-readable identifiers into completely unique machine-readable identifiers?
- avianlyric 3y agoHow 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 deserialisation is expensive when you need every CPU cycle just run your core algorithms)
- zarzavat 3y agoCouldn’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.
- seabass-labrax 3y agoThat sort of thing happens already; for instance, the MCDU of an Airbus aircraft will present various options in the case of ambiguous input, with a distance in nautical miles for each option. Usually, the closest option is the most appropriate.
- avianlyric 3y agoYes 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.
- tortue0 3y agoThey do and use lat/lon in some cases. Reviewing and inputting that (when being done manual) is another story - but it's technically possible.
- gabereiser 3y agoFAA regulations state that fixes, navs, and waypoints must be phonetically transmittable over radio. I.E. Yankee = YANKY. The pilot and ATC must be location aware. Apparently their software does not.
- paulddraper 3y agoAviation protocols are extremely backwards compatible and low-tech compatible. You need to be able to read, write, hear, and speak the identifier. (And receive/transmit in morse code) Would it be okay to have an "area code prefix" in the identifier? Plausible (but practically speaking too late for that)
- epanchin 3y agoWhat three words would be a better solution than a guid, as transmittable over radio.
- dharmab 3y agoW3W contains homonyms and words that are easily confused by non-native english speakers. Often within just a few KM. The latter is why ATC uses "niner", to avoid confusing "nine" and "nein". Talk to someone deep in the GIS rabbit hole and you'll get a rant about how bad W3W is: https://cybergibbons.com/security-2/why-what3words-is-not-suitable-for-safety-critical-applications/ https://cybergibbons.com/security-2/why-what3words-is-not-su...
- tjohns 3y agoAlso, "tree" for 3 and "fife" for 5.
- WalterBright 3y agoWernher von Braun polled his reports for whether the rocket was reliable or not. Each engineer replied "nein". Von Braun reported that the rocket had six nines probability of success.
- chrisweekly 3y agoThat's "What3Words" -- https://en.m.wikipedia.org/wiki/What3words https://en.m.wikipedia.org/wiki/What3words -- a system for representing geographic location using globally-unique word triads.
- bsder 3y agoWTW is a proprietary system that should never be used: https://www.walklakes.co.uk/opus64534.html https://www.walklakes.co.uk/opus64534.html The biggest fault (besides being proprietary) is that you must be online in order to use WTW. The times that you might need WTW are ALSO the times you are most likely to be unable to be online.
- lxgr 3y ago
- gavinsyancey 3y agoIt sounds like for actual processing they replace them with GPS coordinates (or at least augment them with such). But this is the system that is responsible for actually doing that...
- nwallin 3y ago1. 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 of each other. (the name was 'R') This was in violation of ICAO regulations from like the '70s. https://en.wikipedia.org/wiki/American_Airlines_Flight_965 https://en.wikipedia.org/wiki/American_Airlines_Flight_965
- DyslexicAtheist 3y ago> 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
- joshuamorton 3y agoI'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.
- lxgr 3y agoThat's easily fixed – just spell them out using the ICAO spelling alphabet!
- jonny_eh 3y agoThat seems like a huge flaw in their system, has it never been addressed?
- wlonkly 3y agoNo, and by my understanding it can't be, as the algorithm is now permanent. But it's worse than that, there are confusables within small distances of each other: https://cybergibbons.com/security-2/why-what3words-is-not-suitable-for-safety-critical-applications/ https://cybergibbons.com/security-2/why-what3words-is-not-su... https://w3w.me.ss/ https://w3w.me.ss/
- ExoticPearTree 3y agoBecause they need to be short, that's why they are 5 letters long. And need to be understood phonetically very quickly by pilots.