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Airlines are running out of 4-digit flight numbers

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Re: Airlines are running out of 4-digit flight numbers

#431

Post by tyingq »

Aeolun wrote: post #429
kelnos wrote: post #380

Earlier quoted context omitted.

It's not ego, it's marketing, loyalty, and customer comfort. Passengers don't want to see "multiple airlines" in their itinerary. They wonder if the baggage allowances are the same, and if those bags will make it all the way to the final destination. They wonder if they'll get miles on their "main" airline for the whole trip, or if it will be broken up between different loyalty programs. They wonder if the connection…

Codeshares would solve those problems just as well without a separate flight identifier for every airline. Honestly codeshares suck regardless. If I chose an airline it’s because I did not want to deal with their annoying competitors.

Part of what marks it as a code share is those marketing carrier/flight and operating carrier/flight fields that get propagated out lots of places internally and externally. If you just up and change those, then your flight listings would look wonky on, say Expedia. Or your reconciliation process to get the revenue in the right place might break, etc. Two examples of which there are many more.

So the ego thing is somewhat true, but that decision happened long ago, and already created tendrils that are hard to unwind.

Re: Airlines are running out of 4-digit flight numbers

#432

Post by ungamedplayer »

tyingq wrote: post #243
jll29 wrote: post #227

> Here’s the full answer, along with how they triage the problem – for instance by assigning the same flight number to more than one flight a day (although that means they need for it to be flights that would never both be in the air at the same time, such as where the same plane is used and can’t reasonably be substituted) This sounds like it's calling for trouble! Whenever I hear that any IDs could be "recycled", I…

>Whenever I hear that any IDs could be "recycled", I make a mental note to replace the person making such a proposal from all teams that I am involved in. I understand the sentiment, but in this case, someone is trying to solve for constraints they didn't invent. Flight number was fixed to 4 digits long ago and propagates out to a lot of different systems, many not in the same company as the airline, also many being…

Sounds like they are artificial constraints.

I'm sure it sucks that it's "four digits only" but the air travel industry isn't immune from changing specifications. I believe ancient cultures called this software maintenance.

Re: Airlines are running out of 4-digit flight numbers

#433

Post by rightbyte »

rappatic wrote: post #339
delta_p_delta_x wrote: post #292

Earlier quoted context omitted.

> I'm certain each flight has its own completely unique ID buried somewhere in a database There is. It's called the Globally Unique Flight Identifier (GUFI), and it's essentially a UUIDv4[1]. [1]: https://docs.fixm.aero/#/general-guidance/flight_identificat...

This line made me chuckle: > The `Aircraft Identification` is NOT an identifier of an aircraft. It is an identifier of a flight.

Naming things are hard you know ...

Re: Airlines are running out of 4-digit flight numbers

#434

Post by bradknowles »

ryukoposting wrote: post #259
jll29 wrote: post #227

> Here’s the full answer, along with how they triage the problem – for instance by assigning the same flight number to more than one flight a day (although that means they need for it to be flights that would never both be in the air at the same time, such as where the same plane is used and can’t reasonably be substituted) This sounds like it's calling for trouble! Whenever I hear that any IDs could be "recycled", I…

I'm certain each flight has its own completely unique ID buried somewhere in a database. But, shorter codes can be spoken into a radio faster and with lower probability of misinterpretation - both critical features for air traffic control. Those shorter codes will necessarily be reused, it's just a question of the time interval between re-uses of any particular code. I faintly recall seeing two Southwest flights from…

Flight codes are meant to signify the particular starting point, stops, and destinations that will be made along the way.

You can change the aircraft and the flight code stays the same. Many flight codes happen on a regular schedule, like daily. But the same flight path and pattern at a different time on the same day will get a different flight code.

Some patterns have many flights per day along the same path — maybe ten or more. But they each get a different flight code.

All of this is within a single airline or codeshare, of course. Two different airlines can use the same four digit set of numbers for totally different flights, because the full flight code includes both the airline designator and the four digit number.

Re: Airlines are running out of 4-digit flight numbers

#435

Post by jachee »

everforward wrote: post #416
FeepingCreature wrote: post #234

Earlier quoted context omitted.

I don't really understand. My router gives me an IPv6 address...

Do your devices behind the router get IPv6 addresses, or just the router itself? I wouldn't be super surprised to see routers getting IPv6 addresses and doing a 6in4 NAT, so devices behind the router get IPv4 addresses. I would be surprised and impressed if your devices were actually getting public IPv6 addresses. IPv6 can be kind of unwieldy, but the bigger issue to me is that old and/or very cheap clients (like bar…

Every device on my LAN that responds to Bonjour on `.local` uses link-local IPv6 without me having had to do any configuration or put any thought into it whatsoever. ¯\_(ツ)_/¯

EDIT - Oh, you’re talking about public IPv6… similarly, my router (a TP-Link Archer 1200) gets assigned a prefix by my ISP, which it then auto-assigns inside devices IPs from, again without any explicit configuration or intervention on my part. Super easy.

Re: Airlines are running out of 4-digit flight numbers

#436

Post by kalleboo »

lxgr wrote: post #162
kalleboo wrote: post #127

Earlier quoted context omitted.

I don't know about "arbitrary" but most of my travel I book with something like Expedia ends up being split across carriers without using codeshare numbers. E.g. over Christmas I visited my parents in Australia and the domestic leg to Tokyo was a JL flight number, and international leg was a QF flight number, both on the same itinerary/using the same confirmation code.

A CRS/GDS locator (PNR, the 6-digit alphanumeric code often used to identify tickets, but really only points to a GDSs database entry) and a ticket are not the same thing, though. A PNR can include non-air travel segments like hotels and rental cars too, for example. That's something very different from a single airline issuing a ticket for a complete itinerary, which importantly makes them responsible for getting yo…

There was a single ticket number for the itinerary, starting with 081 (Qantas)

Re: Airlines are running out of 4-digit flight numbers

#437

Post by conductr »

kelnos wrote: post #377
conductr wrote: post #179

Earlier quoted context omitted.

That comment explains the issue but exaggerates the impact. Sure, a change can be made and alphanumeric may not be right. No it won't be anything like the recent Crowdstrike issues. The impact of making a change on downstream systems is solved by planning it out. Communicating the intent and setting a switch over date. Some people may not heed the notices and their systems will crash. That's unfortunate, but just lik…

> Some people may not heed the notices and their systems will crash Some of these systems are indirectly responsible for keeping people safe and alive. This "oh well, you should have paid attention and taken care of it" attitude won't fly.

Nice "won't fly" play on words!

Seriously, this is something that could have been rolled out over the course of years. They could have talked about it at industry conventions and otherwise socialized the idea of updating dependent systems. Are those mission critical systems just willy-nilly connecting to these systems? Or is there some authentication? Because if there's authentication, there's usually some record of contacting the admin of that other system. Like how API service providers know who the owners of API keys are. Make it a required step of their annual FAA filings to certify that they have become 5 digit compliant (or whatever it gets called). If there's a way to make them prove it, make them prove it. If it has to be done to each aircraft, require it.

You get my point, there's so many practical ways to handle this. That's not to say it's easy but it's possible. Even just an audit of systems relying on communications to these legacy system(s) for actual flight operation would be a useful thing that I'd think most airline operators should have documented somewhere.

My thought in that comment was the further way from mission critical systems are the ones that will be more likely to unintentionally ignore the switch over notices and have a crash. At that point we're talking about Kayak.com going down or something that is absolutely not mission critical.

We need to have a way of rationally solving this issue that's not just some throw our hands up and ignore the problem until it's critical type situation. It a reality of our technical world that old stuff will require some breaking updates at some times.

Re: Airlines are running out of 4-digit flight numbers

#439

Post by JCharante »

AnimalMuppet wrote: post #294
rhplus wrote: post #258

Earlier quoted context omitted.

Customer behavior is key here. There’s perceived risk with the dreaded “Multiple airlines” option when booking tickets, especially for international flights. No-one wants to find out the hard way that there weren’t agreements or reciprocal status or matching luggage allowances, etc. The code-share is shorthand for “we’re responsible”.

It's also shorthand for "yes, you'll get miles in our plan for this flight".

There are so many agreements for crediting frequent flyer miles that while yes it can help reassure people, there is a million more routes that still credit miles without codeshares to the point where it's useless

Re: Airlines are running out of 4-digit flight numbers

#440

Post by JCharante »

rhplus wrote: post #258
JCharante wrote: post #222

Earlier quoted context omitted.

My solution: Stop codesharing with marketing flight numbers that are useless. Airlines do perfectly fine selling tickets without having the flight marketed by themselves and they can handle inter-airline agreements without it.

Customer behavior is key here. There’s perceived risk with the dreaded “Multiple airlines” option when booking tickets, especially for international flights. No-one wants to find out the hard way that there weren’t agreements or reciprocal status or matching luggage allowances, etc. The code-share is shorthand for “we’re responsible”.

It's safe to assume that if you book on Delta's site then any routings they offer you will have interline agremeent.

Let's say you are traveling from Incheon to Atlanta on a flight with a Delta number. Would you go to the Delta desks to check-in? Maybe... is it a real Delta flight or a flight operated by Korean Air but marketed by Delta? I think getting rid of codesharing would make it much easier for travel novices.

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