Reminds me of the excellent, and frequently surprising 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.

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: https://youtu.be/93lLXNsWp9Q

Falsehoods airlines believe about flight numbers.

> 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.

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.

(This is from August 19, it was widely reported at the time.)

Two planes, the same airport, crossing paths.

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.

"Hey ChatGPT, could you find me a suitable number for this flight?"

What amazes me is that their software has never been updated to support flight numbers longer than 4 digits.