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Two American Airlines Flights End Up with the Same Flight Numbers

62 points · 34 comments · samch

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samch · 1791054438 · focus · HN ↗
Two planes, the same airport, crossing paths.
dmazzoni · 1791056681 · focus · HN ↗
(This is from August 19, it was widely reported at the time.)
kayson · 1791056882 · focus · HN ↗
It's even worse than just the same flight number. Both were at PHX, one landing, one taking off at the same time. Kudos to a clever ATC for preventing what could've been a catastrophe: <a href="https://youtu.be/93lLXNsWp9Q" rel="nofollow">https://youtu.be/93lLXNsWp9Q
1. Sophira · 1791057425 · focus · HN ↗
  The YouTube video you link to is actually about a separate incident from the one described in the article. The video is about an incident involving two AAL2482s near Phoenix; the article is about an incident involving two AA5083s near Providence.
  It's the same idea though; one was inbound, the other outbound, and ATC had to distinguish between the two.
  [edit: Corrected locations.]
2. oatmeal1 · 1791063519 · focus · HN ↗
  The probability of it becoming a catastrophe was infinitesimally low with the existence of TCAS.
  1. cucumber3732842 · 1791072295 · focus · HN ↗
    Not to mention the huge WTF factor of them being in different parts of their flight.
    "Hey why did you just tell a flight that's on approach to taxi"
    "What do you mean they're right here?"
    "No they're on final you twat"
    "No this is patrick"
    ????????
    <issue straightened out>
3. [deleted] · 1791072203 · focus · HN ↗
  [deleted]
stackghost · 1791058102 · focus · HN ↗
Root cause:
> American assigns the same flight number to the outbound and return services, with the same aircraft typically operating both legs.
Other airlines don’t do this, and instead assign a different flight number to the return flight.
1. genocidicbunny · 1791062427 · focus · HN ↗
  Alaska does the same too. Especially with their shorter flights, you might have more than 2 of the same flight per day.
  1. Ekaros · 1791062617 · focus · HN ↗
    Sound like that would be absolute pain if not for customer anyone who just got flight number and wanted to track the process. Or at least I took that as having multiple flights leaving at different times during the day... Couldn't you even have different flights departing at same time with same number in weirdest case?
2. koyote · 1791071549 · focus · HN ↗
  The US is really weird with flight numbers and I don't think any other country in the world does it the same way.
  You often get flights sharing the same flight numbers such as JFK-SLC and SLC-SFO being the same flight number, even if it's a completely different plane doing the route!
  Also super confusing when trying to search for your (or a loved one's) flight online as you'll get multiple matches.
  1. stackghost · 1791073764 · focus · HN ↗
    The US obstinately behind the rest of the world in many ways.
    American exceptionalism at its finest.
ranger_danger · 1791058225 · focus · HN ↗
What amazes me is that their software has never been updated to support flight numbers longer than 4 digits.
1. Razengan · 1791058592 · focus · HN ↗
  Given how long humans have had to implement or fix the most basic of shit (some major apps with millions of users still don't have a Dark Mode, for example) maybe handing the reigns to AI is for the better after all..
  Certainly couldn't get any worse, I mean
  1. boredatoms · 1791064193 · focus · HN ↗
    Dark mode probably doesn’t generate revenue
2. lokar · 1791059163 · focus · HN ↗
  What would the short term ROI on that change be? That’s all they care about.
3. amelius · 1791060042 · focus · HN ↗
  Would not be very convenient to view on a radar screen.
4. gspr · 1791062738 · focus · HN ↗
  Europe for one have used alphanumeric flight numbers for year.
5. MiroslavPokorny · 1791083947 · focus · HN ↗
  Theres a simpler change, how is it possible to allocate numbers without first verifying said number is unique.
gausswho · 1791058733 · focus · HN ↗
I'd like to hear more from someone in the industry about the resolution to this problem. As I understand it, we're trading a small non-zero risk of mistaken identity for the streamlined communication of using four digits rather than five (which carries its own non-zero benefit to safety). This has become a problem because airline consolidation means some of them operate so many flights per day that their limited pool of numbers dictate that they reuse them for either direction.
Could we resolve this by swapping one number for a letter? 26 options instead of 10 raises the pool substantially. Letters A-J indicate inbound, K-Z outbound? Or westbound/eastbound.
1. xenadu02 · 1791059678 · focus · HN ↗
  The format is SSIM defined by IATA - the international association of transport airlines. It specifies two letter airline code followed by four digit flight.
  I'm sure various ATC systems also assume this.
  Changing it would be an industry-wide effort.
2. ycan · 1791059932 · focus · HN ↗
  Alphanumeic call signs are already used around the world [0], it's just that the US (like many other aviation fields) is behind the times.
  [0] <a href="https://www.flightradar24.com/blog/aviation-explainer-series/clearing-up-call-sign-confusion/" rel="nofollow">https://www.flightradar24.com/blog/aviation-explainer-series...
3. yallpendantools · 1791060660 · focus · HN ↗
  > “(No airline can use five-digit flight numbers! While this has been debated in the industry for years, the level of effort to make the change from four to five digits would be huge, and even the level of technology change to add alpha characters to published flight numbers would be gargantuan…although it would be fun to ‘name’ flights—‘Now boarding, Southwest Airlines Flight FRED to Los Angeles.’)”
  <a href="https://www.latimes.com/travel/la-tr-spot-flight-numbers-20180114-story.html" rel="nofollow">https://www.latimes.com/travel/la-tr-spot-flight-numbers-201...
  I'm not from the industry but I could imagine a handful of reasons why I wouldn't want letters in my flight id codes:
  - Some letters and numbers are visually interchangeable. ATCs would have to distinguish between flight HINOOB and H1N00B. Good luck with that.
  - For flights crossing international airspace, there is a risk of miscommunication because letters are not pronounced similarly throughout the world ("zee" vs "zed"). You might think the NATO Phonetic Alphabet solves this but consider "delta" which might also be the airline or "india"/"quebec" which can be destinations. Also, pronunciation has, believe it or not, still not been completely standardized worldwide to this day.
  - Airline codes are already alphanumeric. I am pretty sure there are regular expressions taking advantage of this fact.
4. pbhjpbhj · 1791075384 · focus · HN ↗
  Which airlines have 10,000 flights in progress at time?
  ChatGPT says AA have the most, 1500 planes - 4 digits is plenty.
  1. gausswho · 1791076656 · focus · HN ↗
    [dead]
5. burnt-resistor · 1791098543 · focus · HN ↗
  Too much complexity. It would be simpler to follow GA conventions of using partial registration numbers, perhaps 2 to 4 suffix characters.
amelius · 1791060210 · focus · HN ↗
Falsehoods airlines believe about flight numbers.
1. readthenotes1 · 1791063516 · focus · HN ↗
  Iirc, AA/Sabre knows that a flight identifier is actually carrier+flight number+origin airport+departure date.
  But who all calls someone by their full name all the time??
2. JumpCrisscross · 1791072270 · focus · HN ↗
  Well, and ATC. Airliners’ callsigns are their flight numbers.
amelius · 1791060280 · focus · HN ↗
"Hey ChatGPT, could you find me a suitable number for this flight?"
1. m4ck_ · 1791069638 · focus · HN ↗
  UUID is the obvious answer. "d4580737-1168-4399-b747-8a5e7af5fc97, climb and maintain 14000" just rolls off the tongue.
BJones12 · 1791061143 · focus · HN ↗
> American assigns the same flight number to the outbound and return services, with the same aircraft typically operating both legs.
So they could just not do that.
1. expedition32 · 1791061364 · focus · HN ↗
  Maybe they ran out of numbers I mean there are only so many...
  1. chneu · 1791062318 · focus · HN ↗
    We need IPv6 for aircraft identification.
    Lol
vessenes · 1791065212 · focus · HN ↗
Reminds me of the excellent, and frequently surprising <a href="https://flightaware.engineering/falsehoods-programmers-believe-about-aviation/" rel="nofollow">https://flightaware.engineering/falsehoods-programmers-belie..., which includes surprising false statements like:
“Everything that has an ICAO code is on Earth”, and “flights are at most a few days long”. The whole list makes you despair of structuring any data, ever.
burnt-resistor · 1791098206 · focus · HN ↗
It happened again 2 days later with 2x AA2482. ATC distinguished them by their phases of flight and locations, and by pilots' voices.
<a href="https://youtu.be/Bb8uYlc_ATo" rel="nofollow">https://youtu.be/Bb8uYlc_ATo

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