I think the issue is that you can't really use counter-drones or automatic weapon systems at an airport due to the threat they pose to the airports operations (automatic rifle systems at civilian airports, which are the ones targeted, wouldn't fly in Germany).
The same is true for jamming, which sounds like a bad idea at an active airport, although targetted jamming will probably work. Not sure how quickly such a system can be deployed however.
So that means you need to wait until operations have paused at which point the drone has already disappeared.
I fell like tracking the drone to identify the operator with strong zoom cameras mounted on the airport might work though. At least some commercial systems seem to use this approach: https://www.dedrone.com/industry/airports
