175 or 250 watt transponder?

On Jan 8, 12:01*pm, Itsaplane wrote:
Needing a replacment, my transponder shop told me that above 15k' the
FAR's require a 250 watt transponder (125w below 15k').

True?

I'm pretty sure that sailplane owners are mostly installing 175 watt
units and flying them to 18k' (and higher in wave windows). *Right?

If this 15k' rule is real, I'm supposing that, since gliders aren't
required to have a transponder except in certain airspace (this
airspace is all below 15k' -- except Class A...) that we're generally
free to install anything we want (except 18k' in Class A?).

Bottom line -- 175 watts or 250 watts?

Eric Rupp
ER
(My Terra TR250D transponder is inop and I'm having trouble getting
parts - anybody have a dead one that we might be able to salvage from?)

Eric,

There must be no soaring anywhere that RAS members live. I am amazed
at where this thread has gone.

Buttom line the vast majority of the transponders sold in the USA for
sailplanes are Mircoair T2000, Becker 175w and Becker 250W (less of
these).

IMHO any one of these will be sufficient and relaible at the altitudes
that sailplanes fly, use with an ACK A-30 encolder (less power draw
than the Amer-King encoder and smaller). The Microair is shorter that
the Becker. Both fit in a 2.25" hole. My customers have had good
results with all.

Decide what you want to pay and any of the above will be
satisfactory.

The Garrecht is not a good idea in the USA because it is not certified
in the USA, also the lead time is 6 months.

Mode S is more expensive and I would not spend the money. Becker Mode
S are available in the USA.

Richard
www.craggyaero.com

On Jan 9, 2:16*pm, DRN wrote:
Because it is RAS: Rampant Aviation Speculation. (with many DB)

Correction, that should be DBA ;-)

Bob Thompson wrote:
This is an interesting thread because I'm also considering the
purchase of a transponder.
Unfortunately, it's necessary to pay attention to what's legal in
addition to what does the job.
If for any reason you bump into someone at 16K (and wouldn't I love to
get there) you can bet that the NTSB and the other guy's lawyer will
know the difference.


As long as the transponder signal was picked up by ATC and the bumpee's
TCAS, I doubt if the transponder issue would be relevant from a legal
standpoint. If the signal wasn't picked up, then it might be relevant,
though I don't understand why the signal wouldn't be picked up --
someone flying at 18,000' will never be more than 3000' farther from the
ATC radar than someone flying at 15,000'. A 3000' variance in distance
shouldn't make a significant difference in the strength of the signal.
Maybe this would become an issue if you were flying at 35,000', and were
directly above the ATC radar.