When will aviation be fixed?

Crossing a sim border into land under access control ("ban lines" - fall forever through the ground, plane may be deleted, returned to you, or left hanging in the air.

Crossing a sim border into land that doesn't allow object entry - fall forever through the ground, plane may be deleted, returned to you, or left hanging in the air. There seems to be no upper limit to this.

Crossing a sim border into a full parcel - fall forever through the ground, plane may be deleted, returned to you, or left hanging in the air. There seems to be no upper limit to this.

This has been a problem for a long long time. Is there any work under way to fix it?

Argent, this actually sounds like buggy behavior — please send a bug report on it if you haven't already; I don't have an update on this, and unfortunately, I don't have a workaround either.