Maybe I'm reading this wrong, but according to the AIM, TRSAs provide
separation between participating VFR aircraft. In class C airspace, there
is only separation between VFR & IFR aircraft. The AIM makes it sound like
TRSAs offer participating aircraft a higher level of separation services
than class C radar services.


"Steven P. McNicoll" wrote in message
ink.net...

"Peter Duniho" wrote in message
...

They are left-over from when Class C airspace was called an ARSA.


Actually, they're left over from an even earlier time.



The main difference between an ARSA and a TRSA was that the former
required participation, while the latter did not. Then, and now, the
TRSA
is sort of "in-between" Class C (mandatory radar services) and Class D
(no radar services).


TRSAs provide a service in-between Class C service and Basic Radar
service.
There are some terminal radar facilities that do not have Class B or Class
C
airspace and are not TRSAs, these facilities provide Basic Radar service.

http://makeashorterlink.com/?R22812C3B



The bottom line here is that TRSAs exist where there's a terminal radar
facility (approach/departure control), but where there's not enough
traffic to justify mandatory participation (as is the case for Class C,
or
Class B for that matter).


But TRSAs do not exist at all such locations. Facilities that provide
Basic
Radar service are identified on sectional charts by a small blue circle
with
an R in it near the airport name.

http://makeashorterlink.com/?F3E722C3B



It's really just Class E airspace, where radar
services are being provided by a terminal controller rather than a center
(enroute) controller (that's a bit of an oversimplification too, but it's
the basic idea).


It's Class D and Class E airspace.



The boundaries show you where the terminal controller provides the radar
services rather than the center controller. The only difference in radar
services is who is providing them; it's still just your run-of-the-mill
Class E services, which are optional wherever you are.


That's not correct. The charted TRSA boundary is well within the
center/approach boundary. The terminal facility provides services on both
sides of the TRSA boundary, probably by the same controller as well.