Bob,

However, the TCAS II
system (which includes the Mode S IFF) is in fact a radar system
(radio detection and ranging).


Ah, Usenet!

I know all that. And I knew someone would play semantics.

When I wrote "onboard radar" I was thinking about good old primary
radar. You know why? Context. The average layman has no idea about the
workings of TCAS. He's thinking about that big antenna in the nose of
the airplane. That is what they think detects traffic. And that is
strictly for weather (and ground).

--
Thomas Borchert (EDDH)