Android: Custom Alert for ALL Aircrafts in a defined area below a defined altitude

Hi,


as topic says i want to set a custom alert
that will be triggered by ALL aircrafts in a defined area below a defined altitude.

In the Android App.

Do i have to set multiple alerts for all aircraft types?
That would be nasty..

Or is it possible to set it for all aircrafts, regardless what type it is,
important is only the area and the altitude...

Thanks in advance...

Greetz
Arndt