On Jul 5, 10:21*am, "BT" wrote:
Transponders are a good thing.. when the other guy has TCAS or TIS
capability.
I would venture a guess it's 50-50 he never saw you and simply reacted to
the TA commands.
The small GA aircraft without a TIS display will still never see you.
BT

"jcarlyle" wrote in message

...
On July 2 (a day with blue skies, a few scattered CUs and typical east
coast haze) a friend and I were thermalling our ASW-20 and ASW-19
sailplanes at 6,000 feet 3 miles SE of Blairstown, NJ (a clearly
marked glider port some 40 miles from Newark Airport and Teterboro
Airport). My Zaon MRX alerted us to traffic at our altitude 5 miles
away, which then rapidly closed on us. Despite our best efforts over
the next 30 seconds, neither my friend nor I saw anything approaching.
Then suddenly we saw a business jet in a 45-50 degree bank less than a
mile away. Apparently my transponder caused a TA on his TCAS, he
looked outside and saw our wings flashing, and he turned away from the
impending collision.

I realize not everyone flies in a high traffic area like that around
NY and PHL. But especially for my soaring friends who fly the
Governor’s Cup course, I strongly recommend you put a transponder in
your ship. They cost less than a glide computer, and while they won’t
tell you where you are, a transponder might just get you home someday…

-John

I hope the real point is that without a transponder you are really are
quite invisible in the system. The GA aircraft has a lot less chance
of avoiding you if you don't have a transponder at all. More and more
GA aircraft are flying with "something", but certainly not TCAS. I
wish numbers were available but look around the airport, certainly the
high performance singles crowd and above seem to have traffic
avoidance toys, including PCAS (e.g Zaon MRX) or more advanced TAS
systems from vendors like Avidyne, or they may have TIS, but that's
getting less interesting nowdays. Or GA aircraft may just be under the
control of ATC or under flight following and get a traffic advisory.
And to counter recent concerns about what ATC does with VFR traffic -
I've had excellent advisories of VFR to VFR traffic when in a
sailplane under flight following (and hear them advisign traffic of
me) - including to unknown VFR (i.e. traffic squawking 1200) and heard
traffic advisories about me to airline traffic when not under flight
following (including Reno approach, before the mid-air).

Darryl