[mytailorisrich]

I admit I have no idea how the system works but if there is an obligation to submit a flight plan in advance then there should also be a standard procedure not to let planes take off or enter airspace if they don't. At the very least there should indeed be a procedure to reject the flight plan even if flight cannot be stopped.

[jebarker]

> "not to let planes ... enter airspace"

How?

[Scoring6931]

Airspaces are already a thing in aviation, and pilots need to seek permission to transit between them. This is done by making the request to air controllers via radio.

https://skybrary.aero/articles/classification-airspace

[jebarker]

I was interpreting "not let" to mean you would actually stop them entering. You're right, the parent post probably meant "deny permission to enter".