[josu]

>Why not use alphanumeric characters?

Someone hardcoded that field 50 years ago and it's impossible to change the type. It would be easier to just abandon planes altogether, and set up a parallel transportation system.

[AnimalMuppet]

I understand that database conversions (especially industry-wide) are hard, but:

> It would be easier to just abandon planes altogether, and set up a parallel transportation system.

Yeah, that might be overdoing it just a bit.