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Airlines are running out of 4-digit flight numbers

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311–320 of 461 posts

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

#311
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…

Short flights out-and-back from a hub can have the same number on the two legs. An example is AA 1992, which today departs PHL 3:06 PM, arrives ATL 5:17 PM, departs ATL 5:57 PM, arrives back at PHL 8:05 PM. (All times US Eastern.)

My mother recently had an itinerary where both her flights were this flight - the PHL-ATL leg on a Sunday and the ATL-PHL leg on the following Saturday.

(It looks like as of Tuesday AA 1992 becomes a DFW-SEA-DFW flight, but it's the same sort of thing.)

I figure this isn't a problem as long as the two legs are flown by the same plane. But what if the PHL-ATL flight were delayed and American decided to fly the ATL-PHL flight as scheduled with a different plane (say because lots of people booked on that flight had connections at PHL?) That seems like it could create trouble.

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

#312
post #265

Earlier quoted context omitted.

Reminds me of the line that network engineers love implementing IPv6 so much they have been doing it for years

We could also have bumped 255.255.255.255 to 999.999.999.999 = 1 trillion IP addresses, easy-to-remember and backward compatibility with legacy devices. Modern clients and servers get IP addresses in these new whole IP ranges and can communicate together. Relatively easy to adapt the code of modern software also since it's about removing a restriction from a client-perspective. Load-balancers and legacy clients use I…

I'm guessing everyone downvotes you for the very strange implication that most software stores IP addresses in ASCII. All networking APIs I'm aware of expect IPv4 addresses as a DWORD.

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

#314
post #171

Earlier quoted context omitted.

Why do airlines even need separate flight numbers for codeshare flights? Why not just use the flight number of the operating airline in the booking? IMO it's just confusing for passengers as well.

The marketing carrier, aka the one with the airline code on the ticket becomes liable for certain things in most countries. Codeshare is one way who is responsible is known to outside parties immediately. It also impacts automatic luggage transfers for layovers. Not to mention, there are bits where if I buy a JAL ticket for AA internationally, I get 2 free checked bags while the same AA sold and operated flight has n…

Most airlines already have vastly different baggage rules for different seat classes so I doubt this really needs to be determined by the flight number.

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

#315
post #122

Earlier quoted context omitted.

Given the history of airlines I'm not quite sure if you're joking or not. Sounds plausible ngl

I know explaining a joke always makes it super funny, but… this is a NetEng joke about IPv6 being overbuilt.

Router: Do you want to hear an IPv6 joke

IPv4_Device: Yea

Router: I'm sorry, you wouldn't get it.

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

#316
post #133
post #87

I remember my wife was on a charter flight with 3 initial letters many years ago (in Europe). And when I tried to look up the arrival, many systems could not handle the flight number. Now slightly unsure whether I did not dream up the whole episode, I did a web search and found https://travel.stackexchange.com/questions/157429/what-is-th... So IATA seems to have formally introduced that in 1994. (Whether they have ab…

It's more likely that the flight in question was using the three letter ICAO code in its passenger facing flight number. I have never known a three character IATA code to be used despite it technically being within the specification.

[deleted]

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

#317

Earlier quoted context omitted.

I thought that airlines that fly the same origin to destination daily at the same time always use the same flight number for that flight each day. At least that's what I feel like I normally see.

Not always but often.

Yeah, always was being generous. Often is probably an accurate qualifier.

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

#318
post #122

Earlier quoted context omitted.

I know explaining a joke always makes it super funny, but… this is a NetEng joke about IPv6 being overbuilt.

IPv6 is seen and used directly by professionals, not the general public. Overbuilding it in the sense being mocked made sense.

The funny thing is that IPv6 is used more by general public more than professionals. Public doesn't notice that their mobile network is IPv6, or that there home internet also supports it. It is the professionals that are dragging feet upgrading the business networks.

More people access Google with IPv6 on weekends, currently 46%, than on weekdays, 43%. Presumably because mobile and home networks are more likely to be IPv6 than offices.

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

#320

I get constantly baffled at the amount of technical debt that goes on in civil aviation. The fact that no one just overhauls the system with backward compatibility and sets a deadline for the migration, is just insane for me. All these specific problems are solved, and in production (in freight for instance) for more than 2 decades now. But aviation just goes on with their 70s system.

Trucks are perfectly fine with waiting outside the freight hub if the transportation management software goes down and loses track of everything. A plane in the air is a ticking time bomb that needs to get on the ground before the fuel runs out. Two trucks being just feet away from each other at speed is perfectly fine. Two planes being within half a mile of each other when they shouldn't be is a critical emergency.

Problems in 2D space are amazingly forgiving compared to those that occur in 3D space. The caution civil aviation has is because of the history of flying that is written in blood.

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