Bob Noel wrote:

1) Reaction times are less of an issue with TCAS because normally
the system will advise the crew of traffic (called a traffic advisory
or TA)
when the conflicting aircraft is (iirc) 40 seconds out. This allows
the
crew to begin scanning for the potential conflict.

You know I'm not an aviator, but 40 secs don't appear that much. A few
secs to initially notice a warning and a few more till it properly
registers would take away much of the 40 secs. Moreover, the pilots
could easily be doing other things at the time - a loo break, chatting
up passengers while on autopilot, munching a snack, even flirting with
a hostess (hope I don't get flamed for suggesting that )...

If it isn't automatic, I think the TCAS should be. For sure.

you have far more faith in automation than I.

and why is it that you don't have faith in automation, Bob? Not having
to use brains, and doing something by rote instead, isn't necessarily a
disadvantage always. The chances of a well-programmed software
consistently doing a collision avoidance routine correctly are better
than two pilots doing so, I'd imagine.

Ramapriya