Quote from kisanna12 on Wednesday 2nd October, 2019, 11:39

I don't think I'm going to get this...

[spoiler]I looked up the airport, but have no idea how curved the flight paths should be, also not sure how to find the letter code for the remaining airports...[/spoiler]

Quote from Escapager on Wednesday 2nd October, 2019, 12:39

They are all 

[spoiler]airports[/spoiler] and you will eventually need all of them for a later puzzle.

It's a bit of work, but Wikipedia has them all.

 

Quote from paul.mueller on Thursday 5th March, 2020, 23:53

I am sure I have found the right intersection, but the IATA code for [spoiler]Chicago[/spoiler] is not accepted.
What am I missing?

Quote from paul.mueller on Friday 6th March, 2020, 00:02

I figured it out.
There is more than one airport in the city.

Quote from Escapager on Friday 6th March, 2020, 00:30

The big clue here is it's 1947. There was only one.