So in the news was a so-called "near miss" incident involving two qantas aircraft. The news has been quoting some necessary separation distances of 1000ft vertcal and 5 nautical miles horizontally. When I was coming back from Perth once (Virgin) I had the privilege of seeing an RAAF Globemaster fly below us (in sort of the same direction, somewhat east of Adelaide). I am sure we could have waved to the RAAF aircrew. The captain of our plane made a remark on the PA about the other plane, but their was no question of any problem. Should there have been??

Modern aircraft now have a collision prevention system which is meant to prevent midair collisions.

The systems on each aircraft talk directly to each other. It doesn't rely on Air Traffic Control.

Since the signal is louder the closer the other aircraft is, potential conflicts can be prioritized.

The systems exchange information about altitude and course, and where the likely collision might be.

Crucially the systems choose which aircraft is to say climb, and which is to remain at present altitude. Ambiguity of who should do what is a factor in ship-to-ship collisions.

An episode of say "Air Crash Investigation" analysed a crash that took place with an early version of this system.

Crucuially, the warning message given by the system in that accident was so "lethargic" that the pilots chose not to page attention to it.

May be it should be a "near hit"...

I gather "near miss" is a media term.  CASA call it a "loss of separation".

Often planes fly 2000ft vertical separation , especially BNEMEL, and that is planned separation.

700ft in this case is an issue, especially when plane 1 was actually climbing into the path of plane 2.

Concern is the Perth bound flight did not detect the east bound flight at all! (the faulty equipment was replaced in Perth)