<<When it is, you will be able to rely upon it in exactly the same way you can rely on the Mode S altitude read-outs.>>
But altitude read-out can only be used when properly verified by ATC. So what happens with ADS-B and how does ATC carry out verification of position?
I can, perhaps, see some benefit for the system in remote areas, but not in busy airspace. As for delegating the task of ATC to pilots, that is ridiculous! Pilots spend half their lives moaning about their workload so would they accept the aditional task of separating themselves from other traffic?
<<The pilots then maintain the required distance or time intervals which in turn allows them to do continuous descent approaches without reducing the arrival rate. It is early days, but just think of what ultimately could be done at European airports, and how much easier both the controller’s and the pilot’s job could become - much better than the old trombone pattern with the pilots trying to second guess the controller and the controller wondering whether the pilots will do exactly as instructed, quickly and accurately. >>
With the greatest respect in the world, Bergerie1, I do not think you have much understanding of busy air traffic situations. Pilots do not try to second guess the controller, nor do controllers wonder if pilots will carry out instructions. As for the "trombone pattern", I presume you are referring to vectoring around Heathrow? Solutions have been proposed, but none has been totally satisfactory. Radar vectoring by experienced controllers who KNOW what is going on in the airspace would be difficult to beat with a cockpit-managed system. Are you seriously suggesting that pilots would have to be as familiar with airspace restrictions and routes as the controllers? It's all pie-in-the-sky!
Oh yes.... when GPS is jammed, which occurs not infrequently, what happens then?