PowerFlarm and transponders while towing?

While aero-towing a Mode-C transponder equipped glider, and using
PowerFlarm and transponder in the tow plane, most of the time the
glider will show up on the PF as a threat aircraft. Since the PF
prioritizes threats, this precludes another more distant "intruder"
aircraft as being displayed as a threat. I'm not entirely sure how PF
really deals with this, but it did prompt the idea of turning the
glider's transponder to standby during the tow. And how best to
accomplish this while minimizing the risk of the glider pilot
forgetting to switch the transponder back to ALT after release?

It’s accepted practice to turn off all but one transponder when
formation flying with power aircraft. This to prevent each transponder
from replying to ATC or TCAS at the same time and each stepping on the
other so the receive end gets interference. This probably has not been
much of a problem with a tow plane and glider because traditionally
few tow planes have had transponders.

At Minden, NV, near a busy terminal area and near approach paths into
Reno, all of the tow planes have transponders, and most of the gliders
do as well. Yet we have not adopted a policy of leaving the glider
transponder in standby mode until tow release so as to prevent the
multiple transponder proximity conflict.

Perhaps a change in our normal tug to glider “radio check” prior to
launch: Tug says “transponder on standby” to glider prior to launch,
glider responds, “on standby”. At tow release, glider uses the term,
“transponder on” instead of the “off tow” or “thanks for the tow” used
currently. If glider does not use that phraseology, tow plane
responds, “check transponder on”.

Comments and suggestions . . .

bumper
zz
Minden, NV

While aero-towing a Mode-C transponder equipped glider, and using
PowerFlarm and transponder in the tow plane, most of the time the
glider will show up on the PF as a threat aircraft. Since the PF
prioritizes threats, this precludes another more distant "intruder"
aircraft as being displayed as a threat.

Do you mean PF can only follow one Mode-C threat? This would be a
significant step down from what my PCAS can do. If this is true the PF
PCAS implementation is very poor. Could anyone who flew with PF
comment on this? How many transponder threats can PF follow?

Based on your statement, the same problem will occur in a gaggle of
gliders with transponders. You will have no choice but to disable the
PCAS or filter out codes 1202, but if you do that any glider without a
Flarm but with a transponder is not going to be visible to you. The
only way this problem can be solved is with Mod-S transponders. You
will then associate Mod-S code with a Flarm ID and filter out
transponder signals coming from a glider equipped with both.

On Feb 24, 7:05*am, Andrzej Kobus wrote:
While aero-towing a Mode-C transponder equipped glider, and using
PowerFlarm and transponder in the tow plane, most of the time the
glider will show up on the PF as a threat aircraft. Since the PF
prioritizes threats, this precludes another more distant "intruder"
aircraft as being displayed as a threat.

Do you mean PF can only follow one Mode-C threat? This would be a
significant step down from what my PCAS can do. If this is true the PF
PCAS implementation is very poor. Could anyone who flew with PF
comment on this? How many transponder threats can PF follow?

Based on your statement, the same problem will occur in a gaggle of
gliders with transponders. You will have no choice but to disable the
PCAS or filter out codes 1202, but if you do that any glider without a
Flarm but with a transponder is not going to be visible to you. The
only way this problem can be solved is with Mod-S transponders. You
will then associate Mod-S code with a Flarm ID and filter out
transponder signals coming from a glider equipped with both.

Can anyone using PF comment on my question? Can you see more than one
transponder equipped aircraft at a time? I found this in the manual:

"The nearest aircraft not equipped with ADSB-OUT or FLARM devices, but
is indicated as
a light green circle, in the example, that
target is 2400 ft below. The circle radius
gives a distance estimation based on signal
strength.
The green circle turns red when close. In the
example, the target is 200 ft above"

From the wording it looks like PF can only track one Transponder
equipped aircraft, which is pretty bad!

On Feb 25, 7:10*am, Andrzej Kobus wrote:
On Feb 24, 7:05*am, Andrzej Kobus wrote:









While aero-towing a Mode-C transponder equipped glider, and using
PowerFlarm and transponder in the tow plane, most of the time the
glider will show up on the PF as a threat aircraft. Since the PF
prioritizes threats, this precludes another more distant "intruder"
aircraft as being displayed as a threat.

Do you mean PF can only follow one Mode-C threat? This would be a
significant step down from what my PCAS can do. If this is true the PF
PCAS implementation is very poor. Could anyone who flew with PF
comment on this? How many transponder threats can PF follow?

Based on your statement, the same problem will occur in a gaggle of
gliders with transponders. You will have no choice but to disable the
PCAS or filter out codes 1202, but if you do that any glider without a
Flarm but with a transponder is not going to be visible to you. The
only way this problem can be solved is with Mod-S transponders. You
will then associate Mod-S code with a Flarm ID and filter out
transponder signals coming from a glider equipped with both.

Can anyone using PF comment on my question? Can you see more than one
transponder equipped aircraft at a time? *I found this in the manual:

"The nearest aircraft not equipped with ADSB-OUT or FLARM devices, but
is indicated as
a light green circle, in the example, that
target is 2400 ft below. The circle radius
gives a distance estimation based on signal
strength.
The green circle turns red when close. In the
example, the target is 200 ft above"

From the wording it looks like PF can only track one Transponder
equipped aircraft, which is pretty bad!

If you don't have any capability to track one Transponder, and now PF
gives you the capability to track the closest transponder equipped
aircraft, and tell you if he is higher/lower than you (and by how
much), and closing or opening, how can that possibly be a bad thing?

In addition, it does flarm/flarm collision warning, and eventually,
igc-format logging and logger approval (summerish according to the
PowerFLARM talk at the SSA Reno Convention). I expect that the
capability to see others' climb rates on some PDAs will make
recreational cross-country a lot less stressful too...

One man's opinion.

Dan

On Feb 25, 9:26*am, Dan wrote:
On Feb 25, 7:10*am, Andrzej Kobus wrote:









On Feb 24, 7:05*am, Andrzej Kobus wrote:

While aero-towing a Mode-C transponder equipped glider, and using
PowerFlarm and transponder in the tow plane, most of the time the
glider will show up on the PF as a threat aircraft. Since the PF
prioritizes threats, this precludes another more distant "intruder"
aircraft as being displayed as a threat.

Do you mean PF can only follow one Mode-C threat? This would be a
significant step down from what my PCAS can do. If this is true the PF
PCAS implementation is very poor. Could anyone who flew with PF
comment on this? How many transponder threats can PF follow?

Based on your statement, the same problem will occur in a gaggle of
gliders with transponders. You will have no choice but to disable the
PCAS or filter out codes 1202, but if you do that any glider without a
Flarm but with a transponder is not going to be visible to you. The
only way this problem can be solved is with Mod-S transponders. You
will then associate Mod-S code with a Flarm ID and filter out
transponder signals coming from a glider equipped with both.

Can anyone using PF comment on my question? Can you see more than one
transponder equipped aircraft at a time? *I found this in the manual:

"The nearest aircraft not equipped with ADSB-OUT or FLARM devices, but
is indicated as
a light green circle, in the example, that
target is 2400 ft below. The circle radius
gives a distance estimation based on signal
strength.
The green circle turns red when close. In the
example, the target is 200 ft above"

From the wording it looks like PF can only track one Transponder
equipped aircraft, which is pretty bad!

If you don't have any capability to track one Transponder, and now PF
gives you the capability to track the closest transponder equipped
aircraft, and tell you if he is higher/lower than you (and by how
much), and closing or opening, how can that possibly be a bad thing?

In addition, it does flarm/flarm collision warning, and eventually,
igc-format logging and logger approval (summerish according to the
PowerFLARM talk at the SSA Reno Convention). I expect that the
capability to see others' climb rates on some PDAs will make
recreational cross-country a lot less stressful too...

One man's opinion.

Dan

It is bad because my PCAS can track many transponder equipped aircraft
at the same time and give me this information for each one.

I am not talking about Flarm I am all for Flarm but the PCAS
implementation is not good if the PF can only track one transponder
equipped aircraft at a time.

Your assessment is correct. You only ever see an indication for the
closest transponder only target. Since I haven't used a pcas system
before, I don't know how it displays multiple targets, but I think the
flarm implementation is pretty good since it filters out all but the
most relevant threat. That said, we are in a lightly populated area
for traffic, so I haven't been in a situation where there were
multiple targets within say, 4 miles.

So far with 3 flights under my belt with the powerflarm, I've only
managed to find one unknown transponder target. Range and height
variation were very good, but 3-4 miles and 2000ft below is pretty
hard to spot a small power plane. I have yet to be relatively close
to any power traffic. One flight I was getting a transponder beacon
from a friend in a glider and the estimated range was quite good.

The issue with the towplane transponder and glider masking other
threats is a good problem to solve though. Our towplane doesn't have
a transponder so we can't test that at our little club.

Morgan

On Feb 25, 7:43*am, Andrzej Kobus wrote:
On Feb 25, 9:26*am, Dan wrote:









On Feb 25, 7:10*am, Andrzej Kobus wrote:

On Feb 24, 7:05*am, Andrzej Kobus wrote:

While aero-towing a Mode-C transponder equipped glider, and using
PowerFlarm and transponder in the tow plane, most of the time the
glider will show up on the PF as a threat aircraft. Since the PF
prioritizes threats, this precludes another more distant "intruder"
aircraft as being displayed as a threat.

Do you mean PF can only follow one Mode-C threat? This would be a
significant step down from what my PCAS can do. If this is true the PF
PCAS implementation is very poor. Could anyone who flew with PF
comment on this? How many transponder threats can PF follow?

Based on your statement, the same problem will occur in a gaggle of
gliders with transponders. You will have no choice but to disable the
PCAS or filter out codes 1202, but if you do that any glider without a
Flarm but with a transponder is not going to be visible to you. The
only way this problem can be solved is with Mod-S transponders. You
will then associate Mod-S code with a Flarm ID and filter out
transponder signals coming from a glider equipped with both.

Can anyone using PF comment on my question? Can you see more than one
transponder equipped aircraft at a time? *I found this in the manual:

"The nearest aircraft not equipped with ADSB-OUT or FLARM devices, but
is indicated as
a light green circle, in the example, that
target is 2400 ft below. The circle radius
gives a distance estimation based on signal
strength.
The green circle turns red when close. In the
example, the target is 200 ft above"

From the wording it looks like PF can only track one Transponder
equipped aircraft, which is pretty bad!

If you don't have any capability to track one Transponder, and now PF
gives you the capability to track the closest transponder equipped
aircraft, and tell you if he is higher/lower than you (and by how
much), and closing or opening, how can that possibly be a bad thing?

In addition, it does flarm/flarm collision warning, and eventually,
igc-format logging and logger approval (summerish according to the
PowerFLARM talk at the SSA Reno Convention). I expect that the
capability to see others' climb rates on some PDAs will make
recreational cross-country a lot less stressful too...

One man's opinion.

Dan

It is bad because my PCAS can track many transponder equipped aircraft
at the same time and give me this information for each one.

I am not talking about Flarm I am all for Flarm but the PCAS
implementation is not good if the PF can only track one transponder
equipped aircraft at a time.