LowViz,
Over the last ten years, i have had a half dozen FALSE TCAS RAs. Don't know why they happened but in several cases a TA rapidly progressed into RAs and we took the required maneuver but there was no one there, not visually, not on TCAS after the event and not on radar with ATC.
Fair enough, but I can't see what erroneous RAs have to do with the method of following them. I hope you are not suggesting that pilots assess whether the RA is valid and then follow it if they believe it is?
what do you do with such failures of the TCAS systems when you hook an AP up, to vault one way of the other at will, and possibly into oncoming traffic in RVSM airspace just 1000' above or below you?
Again, I hope you are not suggesting pilots make up their own minds about the validity of an RA before following it. A typical RA would not use more than 500ft of altitude (unless the aircraft is already climbing and descending) and therefore the "third party" aircraft would still be adequately separated. I would expect that if it's TCAS thought there was an issue, it would issue an avoiding RA too. It is easy to create a scenario where TCAS would be overwhelmed, but in reality, does it happen often, and would we have been better off without it? I suspect the answer is "no".
It would also be interesting to know how many false RAs are now occcurring with Change 7 software.