(BHelman) wrote in news:f3ff9ccc.0403162225.3b6f1695
@posting.google.com:

From what I read they can give 3D info
within a certain volume by using the Mode "S" transponder. What I
realized is that if I travel outside this area I will be blind to
other traffic. This may be a correct assumption or possibly not,

The "Mode S ability" you are talking about is called TIS. It's really just
a way of uplinking the ATC data to your aircraft via the datalink
capability of your Mode-S transponder. In spite of the fact that Mode-S
was a really dumb way of implementing it (but they needed some way to
justify the cost of Mode S, and this was one more way), it works pretty
well -- when you are within the service volume for a TIS ground site.

In the NE US you will probably find pretty much continuous coverage.
Elsewhere it gets pretty spotty. In Texas where I fly, last time I looked,
there were only three small area in the entire state that even claimed to
have coverage. Basically, it's a Terminal Area thing, never claimed to be
of any use in cruise.

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James M. Knox
TriSoft ph 512-385-0316
1109-A Shady Lane fax 512-366-4331
Austin, Tx 78721
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