Snowbird,

Sorry for the delay in answering.

would you mind expanding a
bit upon what you like about TPAS and in what circs you find
it "don't leave home w/out it" useful?


Yes, I fly in Europe. Well, when the owner of the aircraft I fly (a
Tobago) first suggested we get one, I thought: "Who needs this?" After
having flown with it for a year I would say it is extremely cheap
insurance, for somewhere between 600 and 1200 $. It gives you an extra
warning to look outside and scan for traffic - which is very useful if
your plane has a lot of gagdets like our Garmin 430.

As you know, it will only say that something is out there somewhere
(lately, also at which altitude), but no direction to look at. That, we
found, is no problem at all - at least not a problem worth investing
another 10k $ or so, which is the price of azimuth-capable systems. You
just look outside and normally find the traffic real soon - if it is
yet close enough for visual ID.

As you also know, it will not alert to gliders or other traffic without
a transponder. The fact that the transponder has to be interrogated is
not a problem here - Europe has either radar coverage or enough
airliners overhead with TCAS triggering transponders. Gliders and
#*?\&% idiots with their transponder switched off are a problem. So you
still have to scan for traffic. But the unit wakes you up.

As for overload in high traffic areas: With the unit we have, you can
set it to only voice alert really close traffic. That works quite well.
And in a busy traffic pattern, I normally switch the voice alert off.
Does that make the unit not worth having? Of course not!

So, basically, it is a great and cost-efficient tool - and it has made
me look outside a lot at times when I had become complacent about
traffic scanning. Did it actually prevent me from hitting someone?
Well, the big-sky-principle still holds, but it is nicer to know if
someone is out there.

Yes, as Thierry mentions elsewhere, we liked the unit so much that we
decided to offer it in our little pilot shop here. But I was less than
convinced before I actually flew with the unit.


--
Thomas Borchert (EDDH)