Jay Honeck wrote :
1. Provide radar separation in all controlled airports
2. Ban converging patterns at non-radar, controlled airports
3. Make non-radar controlled airport uncontrolled -- period
4. Call non-radar controlled airports what they really a
Semi-Controlled

I know that you know that separation is the pilots responsibility in
class D, but it seems that you still expect the tower controller to be
responsible for it. I fly out of a pretty busy Class D and frankly, I
don't expect the tower (equipped with D-BRITE radar) to keep me away
from other planes at all. I also expect either the tower or some
flying doofus to occasionally screw up and cause a conflict (which
happens a few times a year). The way I look at it, the guy in the cab
is going to do his/her best to sequence everybody without conflicts
and that's the extent of their responsibility. I treat a class D
airport just like I would a busy uncontrolled airport, with the added
benefit of someone giving their best guess about other traffic I may
encounter. I guess I'm saying that we as pilots should already know
what you suggest in #4. Class D airports are semi-controlled as far as
separation is concerned.

Radar is not always the answer. Many towers are equipped with
D-BRITE radar displays which are just remote displays of a radar
located at another airport. While the D-BRITE has the capability of
issuing a conflict alert to the controller, you shouldn't feel safer
knowing that the tower is so equipped. Since actual radar site is not
on the airport, towers with D-BRITE often cannot see traffic in their
own traffic pattern. A local example of this is Scottsdale, AZ (SDL).
Their traffic pattern is 2,500 ft., but the radar only sees down to
3,000 ft. Several years ago, there was a midair at SDL between a plane
entering the downwind and one that was already in the pattern. All of
it happened out of sight of the radar.

John Galban=====N4BQ (PA28-180)