Originally Posted by
Bell_ringer
Fair enough, but at some point they would have reported their position and intentions.
No. That is uncontrolled airspace surrounded by half a dozen training airfields and a couple of gliding clubs, as well as being en-route between any number of destinations. What radar service there is would be swamped by regular position reports, which would also be a nuisance to most of the training traffic.
See and avoid, or sense and avoid are the only viable strategies in areas like that.
G