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