Feds Want to Equipe Gliders With Transponders and Radios

On Apr 28, 3:18*am, WingFlaps wrote:
*I am sure that the nicely curved
body of a high performance glass glider has a much lower radar cross
section than any aluminium GA aircraft. It's not stealth but
fiberglass is so transparent it's used for radomes.


The RCS of glass gliders is quite large because of all the metal push
rods. Tests with local radar (Luke Air Force base) showed no
significant improvement in primary target return if a corner reflector
was added.

I have been easily tracked by approach control in my ASW19 and had
them vector traffic round me as I climbed. They do have to want to
see you though and, as others have pointed out, it's likely that the
radar display will be set to filter out a slow moving primary target.


Andy

Larry Dighera wrote:
radar energy as aluminum.

The issue in equipping gliders with transponders, the way I see it, is
the high power consumption required by transponders. Here's a typical
glider transponder: http://www.airplanegear.com/becker.htm
It seems to draw 175W to 250W. That's not insignificant, and way more
than the comm radio consumes. Then there's the weight and antenna
that reduce performance, not to mention the cost of the equipment,
installation, and maintenance.


You may have made a small mistake: 175 to 250 Watts
is the pulse output power. In the same document, the
current consumption is about a half ampere at 14 V,
which is 7 Watts.

--

Tauno Voipio (CPL(A), avionics engineer)
tauno voipio (at) iki fi

On Apr 29, 5:51*am, Larry Dighera wrote:


I would guess the controller would need to adjust his scope from it's
usual setting to see primary targets, so a radio call may be
necessary. *While a corner reflector would doubtless increase the
radar energy returned to the radar antenna and provide a brighter
primary target, I doubt that would be sufficient to cause the glider
so equipped to become visible on ATC's scopes without reconfiguring
them to display slow-moving primary targets.


How slow does a target need to be to be undisplayed -typically? I
would have thought that even a glider is fast (45 knots) compared to
usual clutter.

Cheers

On Mon, 28 Apr 2008 19:20:20 GMT, Tauno Voipio
wrote in
:

Larry Dighera wrote:
radar energy as aluminum.

The issue in equipping gliders with transponders, the way I see it, is
the high power consumption required by transponders. Here's a typical
glider transponder: http://www.airplanegear.com/becker.htm
It seems to draw 175W to 250W. That's not insignificant, and way more
than the comm radio consumes. Then there's the weight and antenna
that reduce performance, not to mention the cost of the equipment,
installation, and maintenance.


You may have made a small mistake: 175 to 250 Watts
is the pulse output power. In the same document, the
current consumption is about a half ampere at 14 V,
which is 7 Watts.

You are correct. Here's another with even less power consumption:
http://www.sportflyingshop.com/Avion...ansponder.html
Microair T2000 Transponder, $1,825
Wiring harness for T2000, $149
Ameri-King AK-350 Blind Encoder, $179

Power input: .25 amps @ 27.50 volts;
.4 amps @ 13.75 volts TX,
80 mA RX

I wonder if those power consumption figures include the heater in the
encoder.


Perhaps it's a good idea to require equipping all gliders with
transponders after all. :-(

On Mon, 28 Apr 2008 12:49:07 -0700 (PDT), WingFlaps
wrote in
:

On Apr 29, 5:51*am, Larry Dighera wrote:


I would guess the controller would need to adjust his scope from it's
usual setting to see primary targets, so a radio call may be
necessary. *While a corner reflector would doubtless increase the
radar energy returned to the radar antenna and provide a brighter
primary target, I doubt that would be sufficient to cause the glider
so equipped to become visible on ATC's scopes without reconfiguring
them to display slow-moving primary targets.


How slow does a target need to be to be undisplayed -typically? I
would have thought that even a glider is fast (45 knots) compared to
usual clutter.


I have no idea, but just assumed it was a tunable parameter.

Perhaps one of the ATC folks among the readership of these newsgroups
may offer some input on that subject.

On Apr 27, 7:26*am, Larry Dighera wrote:
If this is implemented, will it affect powered aircraft without
electrical systems too? *


Actually its more than gliders. They're talking about requiring that
we carry a transponder on our boats too. There has also been talk from
the TSA about having boat owners licensed and binding their license to
their craft to ensure that the person is operating the boat he owns/
operates.

-Robert

Thanx Eric.. it's been a while since I checked.. I remember 13 but that may
have been the crappy Becker Radio.
Had two.. both went back for repairs.. and I know at least one Becker
Transponder had to go back too.
BT

"Eric Greenwell" wrote in message
news:RIdRj.174$1m3.73@trndny02...
BT wrote:

Small transponders now are about $1300 plus antenna and installation. It
can be done.

That's a great price! Where do you get these? What brand? The ones I know
about (Becker, Microair) are $1900 plus $200 for the encoder.

--
Eric Greenwell - Washington State, USA
* Change "netto" to "net" to email me directly

* Updated! "Transponders in Sailplanes" http://tinyurl.com/y739x4
* New Jan '08 - sections on Mode S, TPAS, ADS-B, Flarm, more

* "A Guide to Self-launching Sailplane Operation" at www.motorglider.org

"BT" wrote:

Technology is coming for the small transponder, along with ATS-B. Why would
I put a 50# $15K ATS-B system in a $15K glider.

I suspect that you mean "ADS-B Out"

Reference: http://tinyurl.com/33k9m2

You will see responses from me. I am adamantly against it.

Ron Lee

Larry.. it's been a few years since I've been on the ATC side of the radar..
but "we" had to monitor "primary" returns when working low altitude sectors,
Below FL180. I've listened in on the local TRACON ATC frequency when flying
in the "airline approach area" and yes, they are issuing "traffic, altitude
unknown, could be a glider", and I did not call them first to give them a
heads up. This has been in Grob 103s and LS-4, fiberglass with metal pushrod
controls.

Becker Transponders are very popular with glider pilots, I missed on the
price.. it's closer to $1900 plus antenna and install.
http://www.beckerusa.com/products/de...php?search=557



B


"Larry Dighera" wrote in message
...
On Sun, 27 Apr 2008 21:27:54 -0700, "BT" wrote
in :

Larry.. DO you fly gliders?

Not in several years.

From these statements it would appear that you do not.
Gliders may or may not have electrical systems, they do not "generate
power", but stored battery power of a limited life span.
Gliders are small, batteries are small, everything needs to be small.


None of the gliders I have flown have had electrical systems, small or
otherwise.

NTSB "recommends", FAA cannot mandate without a comment period and a
change
to many CFRs.

True, but I'm thinking that it is in our best interest to provide some
guidance to the FAA before they draft their NPRM; hopefully proactive
will be better than reactive.

Technology is coming for the small transponder, along with ATS-B.

Are you able to provide any specific information about that
technology?

Why would I put a 50# $15K ATS-B system in a $15K glider.

Of course, it's worse than that. There would need to be antennas,
cabling, batteries, switches, circuit breakers, ammeter, ... It
wouldn't be very cost effective to equip gliders used for training
with all that, not to mention the resulting degraded flight
performance and maintenance requirements.

Small transponders now are about $1300 plus antenna and installation. It
can
be done.

Can you provide more specific information about them?


My issue is not with TCAS equipped aircraft, but with smaller GA aircraft
that do not have TCAS, do not have a Garmin 430 with TIS (or equivalent)
and
are not talking to ATC. It does no good to have a transponder, when the
aircraft causing the traffic conflict is not talking to anyone. Just
sitting
there FDH and not even paying attention in the traffic pattern.


I'm not sure if there is a solution to that issue short of having a
control tower at _all_ fields. Have you got any ideas?

Last Saturday we had at least 4 transient aircraft attempt to land at the
airport with 15 to 20 knot tail winds, and against the flow of traffic.

While not very smart, it's not a violation of regulations, is it?

They could not even listen up to the radio to figure out the runway in
use,
or even look at a wind sock or a huge flag and see the 15knt winds and
make
up their own mind about the landing runway.

I find the level of competence, diligence, and responsibility of some
airmen to be disappointing, and it's not just the "hobby" pilots. One
wonders how they manage to pass their biennial flight reviews.


What makes you think a transponder in a glider would make any difference.

In rec.aviation.soaring WingFlaps wrote:
On Apr 29, 5:51?am, Larry Dighera wrote:

I would guess the controller would need to adjust his scope from it's
usual setting to see primary targets, so a radio call may be
necessary. ?While a corner reflector would doubtless increase the
radar energy returned to the radar antenna and provide a brighter
primary target, I doubt that would be sufficient to cause the glider
so equipped to become visible on ATC's scopes without reconfiguring
them to display slow-moving primary targets.

How slow does a target need to be to be undisplayed -typically? I
would have thought that even a glider is fast (45 knots) compared to
usual clutter.

A cruising glider is likely to be faster than that. However, gliders
climbing in a thermal are making tight little circles, and I believe this
will look like a stationary target to the radar. Worse, a glider climbing
in wave really will *be* stationary, as the glider will try not to move by
matching airspeed to wind speed at altitude. I have heard stories of
unintelligent GPS units deciding the airplane was parked and shutting
themselves off in this situation.

--
Michael Ash
Rogue Amoeba Software