On Jul 23, 1:05*pm, Darryl Ramm wrote:
On Jul 23, 12:01*pm, Mike Schumann
wrote:



On 7/23/2010 11:57 AM, Darryl Ramm wrote:

On Jul 23, 8:14 am, Mike
wrote:
It looks like the low cost ADS-B UAT logjam has been broken:

http://www.aopa.org/advocacy/article...x.html?WT.mc_i....

While the price is somewhat higher than I would like to see, it's
competitive with buying a transponder coupled with a Zaon PCAS XRX. *If
you are within range of an ADS-B ground station, you get much more
accurate and reliable position data for conflicting traffic, free
weather, lower power consumption, plus you are visible to ATC!!!!

The down sides: *No TSO, so the unit will not currently meet the 2020
ADS-B mandates; *Not visible to TCAS systems.

Check them out at Oshkosh or on the web atwww.navworx.com.

--
Mike Schumann

While it is great to see ADS-B products appearing for the GA market I
do not see this being a practical ADS-B product for glider
applications.

It does not support FLARM serial protocol so there is no way of
getting traffic display or audible alerts via most popular soaring
software or flight computers. My understanding from the manufacturer
is they don't have any interest in supporting this. Has they changed
their minds on that?

None of the third party traffic warning systems that it interfaces to
are tuned/optimized for glider-on-glider situations.

Low power consumption? Are their published specs wrong? Those specs
state a power draw of 0.7A @ 14VDC. If that is accurate then lets
guess 0.8 A at 12 V, plus most installations will need to add the
power requirements for a dedicated traffic display. That power draw is
just not practical for many glider installations.

Yet again I am dissapointed to see you position ADS-B as a replacement
for a transponder. *If there were no other issues with this device,
many glider pilots in high density airline/fast-jet traffic areas will
want/need to keep using a transponder. So I am not sure about the
point of comparing the price to a transponder based system, those
owners (who presumably are the ones buying transponders today) would
want to add the price to a transponder to this system.

The $2,500 price point plus the cost of whatever display system is
needed to make this work, plus in some case where needed, the cost of
a trasnponder, will disappoint many people.

Unfortunately there are just no "low-cost" (well not as low as many
people seem to have been expecting) ADS-B solutions for gliders now
from any vendors.

I am not sure of the point of conparing the cost of a transponder plus
Zaon XRX (which nobody uses in gliders - I am aware of one test
install). Did you mean MRX? *The more interesting comparison for many
reasons, not just cost, is to a PowerFLARM (with 1090ES data-in) +
Trig TT21. That combination will be in the rough same cost range as
the NavWorx ADS-B system plus the seperate display needed to make that
work. But at least there you get full transponder functionality,
integrated traffic display, FLARMs glider-on-glider optimized traffic
warnings (as noted elsewhere you have to wait a while for TIS-B
traffic support) and FLARM-FLARM radio compatibly with other
PowerFLARM devices should they become popular in the USA. But this
1090ES based system would not provide FIS-B (weather etc.) data. Maybe
all these prices will fall some over time but I'd not expect that to
happen soon.

And as a reminder to other folks gliders currently do not need to meet
the 2020 ADS-B mandate. I am hoping that does not change.

Darryl

I am not discouraging people from investing in transponders. *On the
other hand, FLARM is a huge distraction for people in the US. *It's
never going to be a viable collision avoidance technology, given its
virtually zero adoption rate in this country.

ADS-B, on the other hand, does have promise in those areas where you are
within range of a ground station. *TCAS equipped jets will not see you,
but ADS-B In equipped jets will. *So will ATC. *TCAS was always meant to
be a last line of defense against mid-airs. *Instead, it is being used
as a 1st line. *What we need is a change in attitude in the FAA to
actively vector IFR traffic around all visible GA targets, whether
transponder or ADS-B UAT equipped. *This should be something that is at
the top of the SSA and AOPA's priority list.

Interfacing the Navworx or other ADS-B units to glide computers is
something that should not be a big issue if we can generate the
necessary interest in the soaring community to make this worth the
vendors' time. This can either be done by NAVWORX emulating FLARM or the
glide computer vendors supporting the ADS-B / Mode S TIS formats that
all of the other GPS displays that are supported by ZAON and Navworx
implement.

The problem with PowerFLARM and Zaon, is that both of these technologies
rely on other users (TCAS equipped aircraft or ground radars) to
initiate the interogation of transponders. *If that doesn't happen, you
won't see the traffic. *As a result, you are getting a false sense of
security when you are flying in remote areas. *The only solution to this
is for all low altitude aircraft (gliders, etc.) to standardize on ADS-B
UAT. *If we end up with a mixture of PowerFLARM Zaon PCAS, 1090ES, etc.,
we will never solve this issue.

--
Mike Schumann

If you do not want to discouraging people to adopt transponders maybe
you could stop leading discussions on UAT devices by comparing them
price and otherwise to transponders.

As for Flarm (specifically PowerFLARM in the USA) being a distraction.
I'm not sure how the only system that really effectively offers a
solution for glider-on-glider collision avoidance is a distraction. If
somebody was pushing Flarm at the expense of ADS-B products I'd be
worried but again as has been pointed out here before, Flarm or their
distributors are not encouraging adoption of a FLARM protocol only
device in the USA market. They are promoting a PowerFLARM device with
PCAS and 1090ES ADS-B data-in support which at least in my mind
provides a pretty good roadmap for future ADS-B usage.

I expect the PowerFLARM product to get significant traction in the
glider market in the USA and at least to do so more rapildy than any
stand-alone ADS-B product. Especially since it is the only product (in
the USA market) that really is capable of addressing glider-on-glider
collisions avoidance and is actually practical to install in glider
cockpits. There just is not a single other ADS-B data-in (or data-out/
in) product available or likely to be available soon that is practical
for our cockpits so I simply just do not see anything new happening
here except PowerFLARM adoption. And I'd like to see competing
products appear, I just don't see any ones coming for a significant
time. I know I am mixing issues of glide-on-glider and fast-jet/
airliner scenarios but here with PowerFLARM is a product that helps do
both (when used with a transponder, especially a Mode-S transponder
with 1090ES data-out) and that dual purpose I suspect will appeal to
many purchasers.

Costs for ADS-B via PowerFLARM+transponder or other ADS-B systems will
likely keep many people from installing those. However I would not be
surprised to see many contest pilots thinking about installing
PowerFLARM for its FLARM-FLARM protocol capability given recent mid-
air collisions in contests in the USA and overseas. And that it has a
1090ES capability for future is a nice thing. With World contests
heading this way I hope there is a plan underway to encourage use of
FLARM-FLARM devices in gliders flying those contests, where a
significant number of pilots will already be FLARM users, whether they
would use their own FLARM (adjusted for USA frequencies) or PowerFLARM
devices.

The PCAS part of PowerFLARM relies on external transponder
interrogations. The TIS-B part (when supported by their software) will
not. However TIS-B only provides traffic coverage where there is
currently SSR radar (or in some cases multilateration) coverage. This
means that even with TIS-B a PCAS capability may be the only warning a
glider pilots would get of a transponder equipped aircraft where there
is no SSR coverage but there is enough transponder interrogation for
PCAS. So even with TIS-B coverage that PCAS capability is kind of a
nice feature to have, not at the top of my list, but nice. And of
course in addition to being in an area of SSR coverage you also need
ADS-B ground station coverage to receive the TIS-B and ADS-R data for
any of these ADS-B devices.

There is not going to be any standardization on UAT for low-altitude/
GA traffic and hoping for that is really a waste of time. The FAA
finally got it's ADS-B mandate out, it's been a painful process.
Discussion over, there is no low-altitude standardization on UAT. As
I've pointed out before many GA aircraft will likely deploy 1090ES
data-out as its an easy upgrade to many Mode S transponders like the
Garmin GTX-33/330 family. Adding UAT data-out (and data-in) may be
appealing in other cases. *So there will be a mix of nothing, Mode C,
Mode S, PCAS, UAT, 1090ES and Flarm (via PowerFLARM) in our USA glider
fleet and we all need to focus on how to deal with that reality.

Darryl

I want to clarify my comment on Flarm distraction since it did not
come out as I had intended. I agree that promoting Flarm only devices
vs. ADS-B would be a distraction. I am very happy that does not appear
to be happening in the USA. So people buying into the PowerFLARM story
have a roadmap to 1090ES which is a good thing. And given there are no
other practical ADS-B products for use in gliders in the USA I don't
really have a problem with that as long as people realize that long-
term there should be more and more reasons to adopt ADS-B. Given there
are no alternative options I'm just thinking a PowerFLARM is a
distraction, more I look at it as possibly the path that many glider
pilots will get to ADS-B though.

I think there are always "distraction" concerns around adoption of new
technology. e.g. any ADS-B product, including ADS-B receivers of any
type or UAT transceivers worry me if end-users think those devices
will replace trasponders in critical high density airline/fast-jet
traffic areas. In other low-traffic density areas I expect ADS-B by
itself can provide compelling benefits.

Another possible "distraction" with ADS-B receivers, including the
PowerFLARM, is if people do not understand the need for an ADS-B
transmitter for ATC or others to see you, (or likely more confusingly
to people) just for TIS-B and ADS-R to work properly. Many vendors are
less than clear about all ADS-B receivers needing an ADS-B
transmitter, which is one reason I liked Trig's marketing of their new
ADS-B 1090ES receiver even if it is really not suitable for glider
applications. The NavWorx product mentioned here (but not their other
products) is a transceiver so includes the transmitter. I hope that
the marketing of PowerFLARM in the USA is clear on the need for a
separate ADS-B data-out transmitter (e.g. a Trig TT21) for proper ADS-
B operation. This issue is largely USA specific. Of course the FLARM-
FLARM part works without anything else as long as both gliders have
PowerFLARM (or any mix of PowerFLARM and Flarm outside the USA).

Darryl