Trig TT21 Transponder Thoughts?

I need to replace a Terra TRT250D (it's failed for the 5th time). The
only transponder that might fit into the Terra's rectangular cutout in
my crowded panel (if I do some horizontal filling) is the Trig TT21.
The Trig's specifications look good and it has an attractive price,
but it's brand new on the market.

Does anyone have any experience or thoughts about the Trig TT21
transponder that they'd care to share?

-John

Hi John,

Since you are located in the USA, you need to know that the Trig TT21 has
not been approved for use in the USA yet. It has recently received approval
for use in Europe, and it is supposedly in the approval process for the USA.
I look forward to selling them once they receive approval for use in the
USA. They may receive approval in 1 month, 6 months, 1 year, or possibly
never. I hope it will be very soon, but I have no idea.

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

"jcarlyle" wrote in message
...
I need to replace a Terra TRT250D (it's failed for the 5th time). The
only transponder that might fit into the Terra's rectangular cutout in
my crowded panel (if I do some horizontal filling) is the Trig TT21.
The Trig's specifications look good and it has an attractive price,
but it's brand new on the market.

Does anyone have any experience or thoughts about the Trig TT21
transponder that they'd care to share?

-John

On Jun 21, 8:54*am, "Paul Remde" wrote:
Hi John,

Since you are located in the USA, you need to know that the Trig TT21 has
not been approved for use in the USA yet. *It has recently received approval
for use in Europe, and it is supposedly in the approval process for the USA.
I look forward to selling them once they receive approval for use in the
USA. *They may receive approval in 1 month, 6 months, 1 year, or possibly
never. *I hope *it will be very soon, but I have no idea.

Best Regards,

Paul Remde
Cumulus Soaring, Inc.

"jcarlyle" wrote in message

...



I need to replace a Terra TRT250D (it's failed for the 5th time). The
only transponder that might fit into the Terra's rectangular cutout in
my crowded panel (if I do some horizontal filling) is the Trig TT21.
The Trig's specifications look good and it has an attractive price,
but it's brand new on the market.

Does anyone have any experience or thoughts about the Trig TT21
transponder that they'd care to share?

-John- Hide quoted text -

- Show quoted text -

I'm in the same boat as John, are there any other choices for the
replacement of the Terra 250D? Or doesanyone have one for sale?

I already have the hole and slide chassis in place and it died just
last week. My little Libelle and I miss it already.

Wayne at Walker dot org

On Jun 21, 7:14*am, jcarlyle wrote:
I need to replace a Terra TRT250D (it's failed for the 5th time). The
only transponder that might fit into the Terra's rectangular cutout in
my crowded panel (if I do some horizontal filling) is the Trig TT21.
The Trig's specifications look good and it has an attractive price,
but it's brand new on the market.

Does anyone have any experience or thoughts about the Trig TT21
transponder that they'd care to share?

-John

I am not sure that the TT-21 has FAA TSO approval yet. I can see the
TT-31 in the TSO database (TSO-C112 2/29/2008) but not the TT-21. Is
anybody selling the TT-21 in the USA yet? I see claims on foreign
reseller websites for TSO approval for the T31 but I can't find that
claim on Trig's web site (they claim it will be approved) and I can't
find it in the FAA database, it would be great if it was approved.
Their (sole?) USA dealer is www.seaerospace.com and they only seem to
claim the TT31 is TSO approved.

I have no experience with any Trig transponder, but on paper at least
the Trig looks like a really nice device. I am also very curious to
hear from folks who have use it. It is compact, low power, should be
easy to mount with it's two box construction and with an built in
altitude encoder. It is Mode-S and supports ADS-B 1090ES out, which
gives you future compatibility to meet mandated ADS-B requirements.
What that means is that the Trig will support connecting a GPS data
source and broadcast the GPS location over ADS-B using the 1090ES
standard.

BTW some comments on ADS-B....

One thing to be aware of with that, and any 1090ES or UAT ADS-B device
in gliders, is that there is currently no low cost (IFR) certified GPS
unit that can be connected to provide the location data for ADS-B data
out. This problem is identical regardless of whether we are talking
about ADS-B over 1090ES or a UAT device. We've got 10 years or so to
solve that regulatory problem. Coverage is the second issue, there is
currently not good ADS-B coverage across the USA. The FAA has coverage
maps for for ADS-B roll out (both UAT and 1090ES).

That's the "1090ES" or "extended squitter" stuff or sometimes just
written as "ADS-B". The data transfer can be "in" or "out". A
transponder will support out, or both in and out. 1090ES out supports
sending the aircraft location and 1090ES in reads TIS-B traffic data
(or on a UAT also reads FIS-B weather and other data, a UAT can
support data services than 1090ES). And UATs based devices can support
data in or out or both. There are currently no UAT devices approved
for use that are suitable for gliders.


Not all Mode-S transponders have to provide ADS-B support. But I am
not aware of any curent Mode-S transponder sold in the USA that would
interest a glider pilot that does not at least have 1090ES out
capability. If there are any (compact, low power) glider compatible
Mode-S trasnponders that do *not* even do 1090ES out it would be great
to know.

The Trig transponders do not have 1090ES ADS-B out capability but not
1090ES in. Which means they cannot receive TIS-B traffic information
for display on a traffic display. Becker probably make the most
popular transponders in the USA for use in gliders. The current line
of Becker Mode-S claim to support ADS-B in and out but I am not aware
of anybody using this in a glider or any glider compatible traffic
display. It will be nice to see what happens if there is some pricing
competition for glider compatible Mode-S/1090ES transponders once the
Trig TT21 starts being sold in the USA.

The choice of a Mode-S 1090ES transponder gives you flexibility in
future for compatibility with ADS-B and is a much better choice for
traffic avoidance than UAT based ADS-B in traffic areas of mixed jets
and airliners since UAT devices provide *no* visibility to TCAS (and
there is no technical standard in which they can). TCAS is the last
critical part of the collision avoidance safety net and we really need
this when flying in regions of high density fast jet traffic. The FAA
and the industry really assumes that UATs are a supplement to existing
transponders, not a replacement. The nice thing about a Mode-S
transponder is it gives you options for the future, but with mandates
about a decade away a Mode-C transponder may still provide useful
economical life (and could be complemented with a UAT later, or be
replaced with a Mode-S 1090ES out transponder).

Hope that provides some useful information, even if it does not answer
the direct question.


Darryl

Thanks very much, Darryl, for a thorough and very helpful reply. I
have a Mode C Becker in my ASW-19 and I've been very pleased with it,
but I can't fit a 57 mm transponder of any make into the LS8-18
without a major panel rebuild.

The key question for use in the USA is of course FAA TSO approval, and
as you say there isn't a clear answer to that question. I suspect Paul
Remde is correct that it hasn't yet gotten FAA approval, since SEA
says "now accepting TT21 orders" in a 5/28/2009 brochure, and more
importantly, you couldn't find it in the FAA database. However, SEA
does list TSO C112 and C88a approval on their TT21 catalog page! I'll
call SEA tomorrow and try to find out the true story with regard to
FAA TSO approval.

Meanwhile, is there anyone in Europe that has flight experience with
the Trig TT21?

-John

Darryl Ramm wrote:
I am not sure that the TT-21 has FAA TSO approval yet. I can see the
TT-31 in the TSO database (TSO-C112 2/29/2008) but not the TT-21. Is
anybody selling the TT-21 in the USA yet? I see claims on foreign
reseller websites for TSO approval for the T31 but I can't find that
claim on Trig's web site (they claim it will be approved) and I can't
find it in the FAA database, it would be great if it was approved.
Their (sole?) USA dealer is www.seaerospace.com and they only seem to
claim the TT31 is TSO approved.

I have no experience with any Trig transponder, but on paper at least
the Trig looks like a really nice device. I am also very curious to
hear from folks who have use it. It is compact, low power, should be
easy to mount with it's two box construction and with an built in
altitude encoder. It is Mode-S and supports ADS-B 1090ES out, which
gives you future compatibility to meet mandated ADS-B requirements.
What that means is that the Trig will support connecting a GPS data
source and broadcast the GPS location over ADS-B using the 1090ES
standard.

BTW some comments on ADS-B....

One thing to be aware of with that, and any 1090ES or UAT ADS-B device
in gliders, is that there is currently no low cost (IFR) certified GPS
unit that can be connected to provide the location data for ADS-B data
out. This problem is identical regardless of whether we are talking
about ADS-B over 1090ES or a UAT device. We've got 10 years or so to
solve that regulatory problem. Coverage is the second issue, there is
currently not good ADS-B coverage across the USA. The FAA has coverage
maps for for ADS-B roll out (both UAT and 1090ES).

That's the "1090ES" or "extended squitter" stuff or sometimes just
written as "ADS-B". The data transfer can be "in" or "out". A
transponder will support out, or both in and out. 1090ES out supports
sending the aircraft location and 1090ES in reads TIS-B traffic data
(or on a UAT also reads FIS-B weather and other data, a UAT can
support data services than 1090ES). And UATs based devices can support
data in or out or both. There are currently no UAT devices approved
for use that are suitable for gliders.


Not all Mode-S transponders have to provide ADS-B support. But I am
not aware of any curent Mode-S transponder sold in the USA that would
interest a glider pilot that does not at least have 1090ES out
capability. If there are any (compact, low power) glider compatible
Mode-S trasnponders that do *not* even do 1090ES out it would be great
to know.

The Trig transponders do not have 1090ES ADS-B out capability but not
1090ES in. Which means they cannot receive TIS-B traffic information
for display on a traffic display. Becker probably make the most
popular transponders in the USA for use in gliders. The current line
of Becker Mode-S claim to support ADS-B in and out but I am not aware
of anybody using this in a glider or any glider compatible traffic
display. It will be nice to see what happens if there is some pricing
competition for glider compatible Mode-S/1090ES transponders once the
Trig TT21 starts being sold in the USA.

The choice of a Mode-S 1090ES transponder gives you flexibility in
future for compatibility with ADS-B and is a much better choice for
traffic avoidance than UAT based ADS-B in traffic areas of mixed jets
and airliners since UAT devices provide *no* visibility to TCAS (and
there is no technical standard in which they can). TCAS is the last
critical part of the collision avoidance safety net and we really need
this when flying in regions of high density fast jet traffic. The FAA
and the industry really assumes that UATs are a supplement to existing
transponders, not a replacement. The nice thing about a Mode-S
transponder is it gives you options for the future, but with mandates
about a decade away a Mode-C transponder may still provide useful
economical life (and could be complemented with a UAT later, or be
replaced with a Mode-S 1090ES out transponder).

Hope that provides some useful information, even if it does not answer
the direct question.


Darryl

I received an answer directly from Trig today in response to an e-mail
that I sent yesterday.

Trig says that the TT21 "is not yet legal for use in FAA approved
aircraft". Trig is actively working on FAA TSO approval (they already
have European TSO certification), but they say that any date they
might give for FAA approval "would be nothing more than a very very
rough estimate". As for SEA stating C112 and C88a certification, Trig
says that that is a mistake and that they will contact SEA about it.
They feel that SEA wrote that in anticipation that they "will have a
TSO sooner or later".

Trig also says that if I "can wait several months it [will] certainly
[be] worth the wait". I think I'll be doing just that...

-John

On Jun 21, 12:54 pm, jcarlyle wrote:
The key question for use in the USA is of course FAA TSO approval, and
as you say there isn't a clear answer to that question. I suspect Paul
Remde is correct that it hasn't yet gotten FAA approval, since SEA
says "now accepting TT21 orders" in a 5/28/2009 brochure, and more
importantly, you couldn't find it in the FAA database. However, SEA
does list TSO C112 and C88a approval on their TT21 catalog page! I'll
call SEA tomorrow and try to find out the true story with regard to
FAA TSO approval.

One note of caution about relying too much on TCAS for collision avoidance.
TCAS was designed as the last line of defense against collisions when all
else fails. It is NOT designed for use as the primary way to avoid
collisions. Unfortunately, given current FAA ATC procedures, this is the
way it is currently being used.

One of the problems with TCAS and gliders is that the TCAS logic is designed
for typical aircraft. As a result, TCAS is assuming that targets are
traveling in a relatively straight trajectory. Gliders don't do this, so
the TCAS RA may generate advice that actually creates a collision.

If you are really serious about minimizing the threat of collisions, you
also need a device that will show you where the other traffic is. If you
are in an area where there are ADS-B ground stations, an ADS-B UAT
transceiver is definitely the way to go. If you look at the FAA web site,
you will see that there currently is ground station coverage on the entire
east coast, in southern Florida, and in other isolated other areas of the
US. By next summer, there should be a major expansion of the ground station
coverage, with most of the US covered by 2011.

If you are not in an area with ADS-B coverage, a PCAS type of device is an
alternative.

Mike Schumann

"Darryl Ramm" wrote in message
...
On Jun 21, 7:14 am, jcarlyle wrote:
I need to replace a Terra TRT250D (it's failed for the 5th time). The
only transponder that might fit into the Terra's rectangular cutout in
my crowded panel (if I do some horizontal filling) is the Trig TT21.
The Trig's specifications look good and it has an attractive price,
but it's brand new on the market.

Does anyone have any experience or thoughts about the Trig TT21
transponder that they'd care to share?

-John

I am not sure that the TT-21 has FAA TSO approval yet. I can see the
TT-31 in the TSO database (TSO-C112 2/29/2008) but not the TT-21. Is
anybody selling the TT-21 in the USA yet? I see claims on foreign
reseller websites for TSO approval for the T31 but I can't find that
claim on Trig's web site (they claim it will be approved) and I can't
find it in the FAA database, it would be great if it was approved.
Their (sole?) USA dealer is www.seaerospace.com and they only seem to
claim the TT31 is TSO approved.

I have no experience with any Trig transponder, but on paper at least
the Trig looks like a really nice device. I am also very curious to
hear from folks who have use it. It is compact, low power, should be
easy to mount with it's two box construction and with an built in
altitude encoder. It is Mode-S and supports ADS-B 1090ES out, which
gives you future compatibility to meet mandated ADS-B requirements.
What that means is that the Trig will support connecting a GPS data
source and broadcast the GPS location over ADS-B using the 1090ES
standard.

BTW some comments on ADS-B....

One thing to be aware of with that, and any 1090ES or UAT ADS-B device
in gliders, is that there is currently no low cost (IFR) certified GPS
unit that can be connected to provide the location data for ADS-B data
out. This problem is identical regardless of whether we are talking
about ADS-B over 1090ES or a UAT device. We've got 10 years or so to
solve that regulatory problem. Coverage is the second issue, there is
currently not good ADS-B coverage across the USA. The FAA has coverage
maps for for ADS-B roll out (both UAT and 1090ES).

That's the "1090ES" or "extended squitter" stuff or sometimes just
written as "ADS-B". The data transfer can be "in" or "out". A
transponder will support out, or both in and out. 1090ES out supports
sending the aircraft location and 1090ES in reads TIS-B traffic data
(or on a UAT also reads FIS-B weather and other data, a UAT can
support data services than 1090ES). And UATs based devices can support
data in or out or both. There are currently no UAT devices approved
for use that are suitable for gliders.


Not all Mode-S transponders have to provide ADS-B support. But I am
not aware of any curent Mode-S transponder sold in the USA that would
interest a glider pilot that does not at least have 1090ES out
capability. If there are any (compact, low power) glider compatible
Mode-S trasnponders that do *not* even do 1090ES out it would be great
to know.

The Trig transponders do not have 1090ES ADS-B out capability but not
1090ES in. Which means they cannot receive TIS-B traffic information
for display on a traffic display. Becker probably make the most
popular transponders in the USA for use in gliders. The current line
of Becker Mode-S claim to support ADS-B in and out but I am not aware
of anybody using this in a glider or any glider compatible traffic
display. It will be nice to see what happens if there is some pricing
competition for glider compatible Mode-S/1090ES transponders once the
Trig TT21 starts being sold in the USA.

The choice of a Mode-S 1090ES transponder gives you flexibility in
future for compatibility with ADS-B and is a much better choice for
traffic avoidance than UAT based ADS-B in traffic areas of mixed jets
and airliners since UAT devices provide *no* visibility to TCAS (and
there is no technical standard in which they can). TCAS is the last
critical part of the collision avoidance safety net and we really need
this when flying in regions of high density fast jet traffic. The FAA
and the industry really assumes that UATs are a supplement to existing
transponders, not a replacement. The nice thing about a Mode-S
transponder is it gives you options for the future, but with mandates
about a decade away a Mode-C transponder may still provide useful
economical life (and could be complemented with a UAT later, or be
replaced with a Mode-S 1090ES out transponder).

Hope that provides some useful information, even if it does not answer
the direct question.


Darryl

On Jun 21, 10:23*am, "Mike Schumann" mike-nos...@traditions-
nospam.com wrote:
One note of caution about relying too much on TCAS for collision avoidance.
TCAS was designed as the last line of defense against collisions when all
else fails. *It is NOT designed for use as the primary way to avoid
collisions. *Unfortunately, given current FAA ATC procedures, this is the
way it is currently being used.

One of the problems with TCAS and gliders is that the TCAS logic is designed
for typical aircraft. *As a result, TCAS is assuming that targets are
traveling in a relatively straight trajectory. *Gliders don't do this, so
the TCAS RA may generate advice that actually creates a collision.

If you are really serious about minimizing the threat of collisions, you
also need a device that will show you where the other traffic is. *If you
are in an area where there are ADS-B ground stations, an ADS-B UAT
transceiver is definitely the way to go. *If you look at the FAA web site,
you will see that there currently is ground station coverage on the entire
east coast, in southern Florida, and in other isolated other areas of the
US. *By next summer, there should be a major expansion of the ground station
coverage, with most of the US covered by 2011.

If you are not in an area with ADS-B coverage, a PCAS type of device is an
alternative.

Mike Schumann

[snip]


If all you want is TIS-B traffic information then a Mode-S transponder
can get you traffic data, provide TCAS compatibiiey, and also
compatibility with PCAS systems used in some gliders and GA aircraft.
I know Mike knows all this, that comment is to make it clear to
others.

TCAS is the absolute last defence and for high-traffic jet/airline
areas I just hope people will not think a glider would be better off
with ADS-B TIS-B traffic data *instead* of a transponder that provides
visibility to TCAS equipped jets.

While there are arguments about TCAS RA predictions, the RA are based
on altitude and jet traffic can climb or descend rapidly when needed
and the TCAS will monitor what is happening as the threat target
converge. This is not a satisfactory answer but I just worry that many
readers might thing that TCAS is doing some sophisticated track
avoidance and therefore a glider maneuvering might cause far more
complexity than the altitude based avoidance that actually happens.
Being primarily altitude based makes the resolution determination a
lot simpler. Gliders are also relatively slow moving, so even if
maneuvering their relative location to a fast jet does not move
rapidly. Gliders might change climb rates at +/- thousands of feet per
minute but with altitude margins in TCAS and the continuous monitoring
of altitude as targets converge probably make this less of an issue
than it could be. I am not aware of any technical study that shows
serious problems with gliders (or other slow traffic) and TCAS. I'd
love to see any if they exist.

With TCAS on TCAS targets the Mode-S transponders are communicating RA
data to ensure that both aircraft are not instructed to climb etc.
Since a glider won't have TCAS that won't happen, but the real issue
with that is avoiding TCAS directing both the jet aircraft with high
climb/descent performance to do the same thing, and the ultimate fall
back here is the ability of a jet to normally out-climb or out-descent
a glider even if the glider pilot decides to change altitude abruptly
to avoid a collision.

So again, the problem if people just relied on ADS-B UAT devices and a
TIS-B traffic display is that the glider would be entirely invisible
to TCAS. I would much rather have the TCAS help the fast jet avoid me
than me avoid the fast jet. But ideally have both. And ADS-B TIS-B
(either over UAT or 1090ES) offers more range than PCAS - one of the
issues with PCAS (I fly with a Zaon MRX) is it may not have sufficient
range to be useful for fast jet traffic. And even if you have a fancy
TIS-B display you may still decide to make an avoidance manouvre that
conflicts with what TCAS is telling the other aircraft to do. Again
this would rely on the jet typically being able to out climb or out
descend a glider.

Had the ASG-29 flying near Reno a few years ago had a simple
transponder the Hawker jet very likely would not have collided with
with it. ATC hopefully would have given the Hawker a traffic advisory
(but as Mike points out there is no guarantee that currently they
would have since both aircraft collided outside controlled airspace),
failing that the TCAS should have done its job. Likewise with another
incident near Reno more recently a transponder would likely have
avoided the jet pilots and ATC being "surprised" by a glider while on
approach to Reno, and the subsequent hassles for all involved.

BTW people wanting to see what TIS-B traffic on a UAT device might
look like in a real product -- the NavWorx PADS600 receives TIS-B (and
FIS-B) data, it does not do ADS-B out. See http://www.navworx.com. The
receiver is currently ~$1,500 and can display traffic data on a Garmin
496 or several other types of popular GA displays. As Mike points out,
this technology is quite interesting for the future.

Darryl

On Jun 21, 11:28*am, Darryl Ramm wrote:
On Jun 21, 10:23*am, "Mike Schumann" mike-nos...@traditions-

nospam.com wrote:
One note of caution about relying too much on TCAS for collision avoidance.
TCAS was designed as the last line of defense against collisions when all
else fails. *It is NOT designed for use as the primary way to avoid
collisions. *Unfortunately, given current FAA ATC procedures, this is the
way it is currently being used.

One of the problems with TCAS and gliders is that the TCAS logic is designed
for typical aircraft. *As a result, TCAS is assuming that targets are
traveling in a relatively straight trajectory. *Gliders don't do this, so
the TCAS RA may generate advice that actually creates a collision.

If you are really serious about minimizing the threat of collisions, you
also need a device that will show you where the other traffic is. *If you
are in an area where there are ADS-B ground stations, an ADS-B UAT
transceiver is definitely the way to go. *If you look at the FAA web site,
you will see that there currently is ground station coverage on the entire
east coast, in southern Florida, and in other isolated other areas of the
US. *By next summer, there should be a major expansion of the ground station
coverage, with most of the US covered by 2011.

If you are not in an area with ADS-B coverage, a PCAS type of device is an
alternative.

Mike Schumann

[snip]

If all you want is TIS-B traffic information then a Mode-S transponder
can get you traffic data, provide TCAS compatibiiey, and also
compatibility with PCAS systems used in some gliders and GA aircraft.
I know Mike knows all this, that comment is to make it clear to
others.

TCAS is the absolute last defence and for high-traffic jet/airline
areas I just hope people will not think a glider would be better off
with ADS-B TIS-B traffic data *instead* of a transponder that provides
visibility to TCAS equipped jets.

While there are arguments about TCAS RA predictions, the RA are based
on altitude and jet traffic can climb or descend rapidly when needed
and the TCAS will monitor what is happening as the threat target
converge. This is not a satisfactory answer but I just worry that many
readers might thing that TCAS is doing some sophisticated track
avoidance and therefore a glider maneuvering might cause far more
complexity than the altitude based avoidance that actually happens.
Being primarily altitude based makes the resolution determination a
lot simpler. Gliders are also relatively slow moving, so even if
maneuvering their relative location to a fast jet does not move
rapidly. Gliders might change climb rates at +/- thousands of feet per
minute but with altitude margins in TCAS and the continuous monitoring
of altitude as targets converge probably make this less of an issue
than it could be. I am not aware of any technical study that shows
serious problems with gliders (or other slow traffic) and TCAS. I'd
love to see any if they exist.

With TCAS on TCAS targets the Mode-S transponders are communicating RA
data to ensure that both aircraft are not instructed to climb etc.
Since a glider won't have TCAS that won't happen, but the real issue
with that is avoiding TCAS *directing both the jet aircraft with high
climb/descent performance to do the same thing, and the ultimate fall
back here is the ability of a jet to normally out-climb or out-descent
a glider even if the glider pilot decides to change altitude abruptly
to avoid a collision.

So again, the problem if people just relied on ADS-B UAT devices and a
TIS-B traffic display is that the glider would be entirely invisible
to TCAS. I would much rather have the TCAS help the fast jet avoid me
than me avoid the fast jet. But ideally have both. And ADS-B TIS-B
(either over UAT or 1090ES) offers more range than PCAS - one of the
issues with PCAS (I fly with a Zaon MRX) is it may not have sufficient
range to be useful for fast jet traffic. And even if you have a fancy
TIS-B display you may still decide to make an avoidance manouvre that
conflicts with what TCAS is telling the other aircraft to do. Again
this would rely on the jet typically being able to out climb or out
descend a glider.

Had the ASG-29 flying near Reno a few years ago had a simple
transponder the Hawker jet very likely would not have collided with
with it. ATC hopefully would have given the Hawker a traffic advisory
(but as Mike points out there is no guarantee that currently they
would have since both aircraft collided outside controlled airspace),
failing that the TCAS should have done its job. Likewise with another
incident near Reno more recently a transponder would likely have
avoided the jet pilots and ATC being "surprised" by a glider while on
approach to Reno, and the subsequent hassles for all involved.

BTW people wanting to see what TIS-B traffic on a UAT device might
look like in a real product -- the NavWorx PADS600 receives TIS-B (and
FIS-B) data, it does not do ADS-B out. Seehttp://www.navworx.com. The
receiver is currently ~$1,500 and can display traffic data on a Garmin
496 or several other types of popular GA displays. As Mike points out,
this technology is quite interesting for the future.

Darryl

Sorry my first para was supposed to say

If all you want is TIS-B traffic information then a Mode-S transponder
**with ADS-B in** can get you traffic data, provide TCAS
compatibility, and also compatibility with PCAS systems used in some
gliders and GA aircraft.

As mentioned in my first post in this thread the Becker Mode-S claim
to support ADS-B in for TIS-B. If I had a Becker Mode-S and lived near
ADS-B coverage I'd be playing with that now (done on the ground, a few
wires to a the transponder data out pins and see what is is sending
out...).

Darryl

A question regarding ADS-B out capability on a Mode S transponder. Can
you feed the output of a glider GPS, say a Volkslogger, and into the
Mode S transponder?

Since the transponder and the encoder both require TSOs for use in the
USA airspace, I assume the answer to this question is an emphatic
"no".

A similar question for ADS-B in - are you required to display the TIS-
B and/or FIS-B data on a TSOed display?

-John