On Mar 17, 8:12*am, cfinn wrote:
I did some study on the Power Flarm and set in on the presentation at
the Little Rock Convention. It is interesting, but doesn't provide the
capabilities of ADS-B UAT. The plus is that it contains an IGC flight
recorder. It provides very good traffic location for Flarm and ADS-B
1090ES equipped aircraft. It works similar to a PCAS for mode C and S
transponder targets and receives their altitude reports and senses
distance. The traffic location is a good guess and alerts to get your
head up. I'm not sure what it would report if the transponders
altitude reporting was missing as you would have froma mode A
trasnponder. You do not have any of the ADS-B FIS (Flight Information
Services) such as Nexrad weather radar, TFR's, METARs, SIGMETs, etc.
Most importantly, only other aircraft equipped with Flarm would see
you! You would not be visible to ATC or aircraft equipped with TCAS,
PCS, etc.
A UAT does not really make you "visible" to TCAS either.
In addition to all the FIS information that you can receive over ADS-B
UAT, you are visible to ATC.
That depends if the UAT device is a receiver or tramismitter (or
both). Yes I know the "T" in UAT stands for transceiver, so in a sane
world you would think that.... sigh.
Just like with 1090ES there are devices in UAT land that are only
receivers.
You are also visible directly visible to
other ADS-B UAT equipped aircraft. ADSB ground stations relay your UAT
position information to aircraft equipped with ADSB 1090ES. Those same
ground station also transmit all traffic ATC is following (primary
radar, Mode A/C/S transponder, ADSB 1090ES, ADSB UAT). Now you have a
much more complete picture of traffic, expect for Flarm only equipped
aircraft, and ATC and many other aircraft can see you!
But a 1090ES (e.g. PowerFLARM) or UAT receiver gives you that same
"complete picture".
TIS-B is the part that resends what ATC is seeing and it relies on
position ATC position data that requires aircraft to have a Mode-C or
Mode-S transponders. A primary radar target is never retransmitted
over TIS-B. Obviously you need to be within ATC radar coverage for
this to work.
ADS-R is the retramsission by a ground station of UAT to 1090ES and
1090ES to UAT. Since it's bidirectinal a Power-Flarm sees UAT (as well
as it's native 1090ES) traffic as long as it is within range of a ADS-
B ground station.
PowerFlarm (with 1090ES) is clearly intended to be installed along
with a transponder, and I hope people get that. Using it for Flarm
only really does not make much sense in the USA. If you have something
like a Trig TT-21 then that does basic mode-S and is also 1090ES ADS-B
capable so in future you hook up a GPS source to that and be good to
go. Many manufactures (inc. Garmin) are taking this two box approach
to 1090ES, where you add a separate receiver to the aircraft to
complement the Mode-S/1090ES transponder. You will see new products
coming out that do that. Given Europe has gone Mode S, the European
soaring manufacteurs are goign to be focusing on 1090ES based
products.
Be careful in general what you think you are getting with any ADS-B
box. Just being "ADS-B" does not tell you much as to what it does at a
user level. Is it a receiver only, a transmitter only, or both. What
communication protocol does it support to a PDA display? What do I
need to do to get it to display say FIS-B data? If it is a receiver
does it display traffic information? Does it issue traffic alerts? Can
it connect to my PDA to issue pop-up traffic warnings/alarms through
the PDA? Can it display a traffic map on the PDA? BTW most people will
want the box to use the Flarm serial protocol to the PDA (yes Flarm
protocol for ADS-B/TIS-B/ADS-R traffic) since soaring software on PDAs
speak that protocol and we don't have a spare second serial port to
run the Garmin TIS protocol.
The main benefit of a 1090ES transmitter ove a UAT is that since it is
transponder based airborne TCAS systems see it. Even if the aircraft
has ADS-B receivers the TCAS systems do not issue resolution
advisories based on ADS-B. That requires a transponder in the glider.
In high traffic areas where we fly amongst fast jets/airliners I would
rather see people thinking about using transponder/1090ES and add-on
ADS-B receivers (either 1090ES or UAT). The powerFlarm looks like an
excellent add-on for a transponder in that scenario.
I worry about how well we will have ADS-B ground station coverage
along busy low-level routs like major ridge soaring locations, the
white mountains etc. Without that, gliders with UATs and 1090ES will
not see each other. The low-level ground station coverage test maps
I've see are very impressive but still in mountainous terrain we are
goign to have holes. There probably needs to be attention paid to what
the actual coverage is in areas. Look at adopting dual 1090ES/UAT
receivers (some vendors appear to be working on those) or try to
standardize on one standard in an area (driven by clubs or FBOS?).
Since the PowerFLarm is a packaged unit that is available and works
today I think we will start to see some clubs standardizing around
that already for all the PCAS/ADS-B goodness and the proven Flarm
capability in situations like glider-on glider traffic on mountain
ridges. (but still I am really worried that people don't adopt Flarm
alone in the USA where they really need to be moving to ADS-B).
Darryl
I have nothing against Flarm and think it was a great technology.
However, it hasn't been adopted in the US. Why not go with with the
newer technology and receive the additional benefits along with the
safety of visibility to ATC and others? The pricing ranges for power
Flarm that ware discussed at the convention, would be similar to the
total cost of a Flight Recorder and the anticipated cost of the ADS-B
UAT.
Charlie
Have any of you considered this device?
http://www.powerflarm.aero/
It seems to have a lot more capability than just ADS-B
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