In article ,
"Gene Whitt" wrote:

Andrew,
There is RADAR and RaDaR. After a 40 year delay all of the S.F.
Bay Area non RADAR airports have a TV like system called BRITE. Bride does
give the towers a TV like screen that allows the tower to see the VFR
aircraft on radar with a readout of altitude.

The antenna is usually so distant from the airport that it is not certified
to provide a transponder code nor separation.

I don't think the certification of what a controller can do with a brite
scope has much to do with where the antenna is. NY Tracon has (to the
best of my knowledge) 5 antennas, located at JFK, EWR, ISP, HPN, and
SWF. The raw signals from all of the antennas are transmitted to a
secret location in suburban Long Island where the Tracon is physically
located. The various display scopes at all the area airports (the four
Class B and C primaries plus all the dozen or so Class D satellites) are
all then fed remotely from the computers in the Tracon.

HPN, with an antenna right on the field, acts like a satellite airport.
They can't release IFR flight without coordinating with the Tracon, and
the Tracon handles sequencing inbound flights and (in the case of VFR
inbounds) assigning squawk codes before handing off to the tower. The
brite scope in the HPN tower does give altitude and squawk code readouts.

On the other hand, LGA has no antenna on the field (my understanding is
the HPN antenna sees almost to the ground at LGA), but I'm sure they
provide full radar services.

The problem is that some of the tower people become reliant upon
a radar screen that has inherent weaknesses and errors. The visual
skills of the past become less required and proficient. The position
reporting skills of the pilot become more important.

This certainly seems to be the case at HPN. I've had the tower refuse
to allow VFR pattern work because the radar was down. Or limit the
pattern to one or two aircraft. At CDW (in the pre-brite days), they
used to routinely handle 8 guys in the pattern and still work arrivals
and departures on both runways.

A week ago I was with a student in a C-172 where we made a call-up saying
that we were planning on a 45 endtry to the downwind. Immediately
afterwards a twin Commander made the same call. Neither aircraft was able
to find the other and the controller could not distinguish one from the
other since both were squawking 1200. The difficulty arose from the
perception of what constitutes a 45 entry. The Commander was closer to a
direct entry to downwind than a 45.

One of the things I try to impress on students is that the tower at a
Class D airport has no responsibility for separating VFR from VFR in the
air. Most pilots seem to think that the tower is doing more for them
than they really are.

In theory, the controller in your case could have said, "172, maintain
at or below 1000, break, Twin Commander maintain at or above 1200,
report the 172 in sight". That would have ensured you wouldn't swap
paint. But, I'm sure it would have also broken the rules the controller
operates under, so it'll never happen.