The misconception here is that Flight numbers are not treated as IDs. A unique key to any flight is the composite of number/origin/departure date.

And it's mostly a holdover from legacy systems airlines are entrenched in, so there isn't much else anyone can do here short of completely reinventing the mainframe reservation systems and heavily refactoring all the pieces that depend on it.

> isn't much else anyone can do here short of completely reinventing the mainframe reservation systems and heavily refactoring all the pieces that depend on it.

This is commonly called "software maintenance". I believe that most places have contracts to keep software up to date for changing specifications/operating systems.

> Couldn't agree more, not even interested in debating it

Given that the industry has rejected the natural but very expensive solution, and that airlines exist in a connected space, this information is shared with partners and external parties so they can't just change their internal systems, it doesn't seem like there are too many solutions.

One solution could be to assign multiple airline codes per airline, but I'm not sure of the downsides.

Do you have a solution you think would work?

Flight numbers are already recycled (sometimes on the same day). The proposal is just changing the recycling frequency.

This whole argument reminds of something. Found it. (Can't believe that was only 2 months ago.)

You'll regret using natural keys https://news.ycombinator.com/item?id=40580549 (554 comments)