Flarm in the US

On Aug 9, 9:48*am, Mike Schumann
wrote:
On 8/9/2010 11:23 AM, brianDG303 wrote:



On Aug 9, 7:12 am, *wrote:
On Aug 9, 7:56 am, Mike
wrote:

On 8/9/2010 8:43 AM, Steve Freeman wrote:

Curious about the use of Flarm in the US. Was told by another pilot
that the frequency used by Flarm is not approved for that category of
use in the US. Is that true? If it is, do they make units that use a
US approved frequency?

There is virtually no FLARM in the US. *It is unlikely to take off here,
as the biggest threats for mid-airs in the US are between powered
aircraft and gliders or other aircraft.

It's a chicken and egg situation. *FLARM is only interesting if everyone
equips. *No one is going to equip if they don't think that everyone else
will.

With ADS-B coming out, that is the way to go in the US. *If you buy an
ADS-B transceiver, not only will you see other ADS-B equipped aircraft,
but, if you are within range of an ADS-B ground station, you will also
see all Mode C/S transponder equipped aircraft that are visible to ATC.
* *With 80-90% of GA aircraft in the US transponder equipped, this gives
an immediate benefit to anyone investing in ADS-B (assuming that they
have a ground station deployed in their area).

--
Mike Schumann

Mike,
Your points are all well taken. I realize that FLARM has never been
accepted in the US up to now, and we all know that ADS-B is coming in
2020 (although I thought there was a "glider" exemption), but with
that being said, would it make any sense for FLARM units to be
required for gliders competing in any of our nationals (or maybe even
in regionals)?

As you are aware, we've had several mid-airs between gliders in recent
years and perhaps if gliders had been equipped with FLARM units in a
nationals or in a regionals, some of these mid-airs might have been
prevented.....Just a thought!

Thanks - Renny

Mike and Renny,
a good discussion of the macro view of FLARM and ADS-B. Another view
is more personal, for example in my situation- I fly a lot of ridge
and mountain in a very narrow altitude band and a lot of clouds. There
is not a lot of power traffic in those conditions. I have a
transponder but I don't see the Transmit light going off very often
and I suspect I am not getting very many radar paints down in the
rocks and trees where I like to fly. My greatest risk is from the six
other gliders I share the area with, which do not have transponders
and will never get them at the current costs; in fairness my threat to
them is even higher as I am a low hour pilot. FLARM would go a long
way to reducing the risks and at a reasonable cost; PowerFlarm would
be my choice as it would also provide protection from ADS-B and
transponder equipped threats, but at twice the cost the installed base
in my situation would be very much reduced and I stand a better chance
of talking my potentially deadly friends into investing in FLARM. 2020
is not soon enough. It is not soon enough for the pilots killed on a
regular basis at contests, which we seem to simply accept as an
unavoidable risk.

With that in mind Mike's statement that FLARM isn't of use (for me)
would not be correct. In 2004 my club lost two gliders and a pilot in
a collision that would not have happens if they had had FLARM. How do
you calculate that cost?

Brian

Why not convince your fellow pilots to invest in the Navworx ADS-B
transceiver that is now shipping? *FLARM in the US is a dead end. *ADS-B
is the future. *If you invest in a Navworx type of device, not only
would you see each other, but you will also see other ADS-B equipped GA
aircraft, and if you are flying within range of a ground station, ALL
transponder equipped aircraft.

--
Mike Schumann

Ah maybe becasue they draw 0.8 amps, cost $2,495 each, don't warn
about traffic threats themselves, and are not compatible with any
traffic display systems used in glider cockpits. Besides those minor
little inconveniences your suggestion to buy this specific ADS-B UAT
transceiver is wonderful.

---

Anyhow back to the factual stuff... Flarm in the USA is not a dead-
end. Flarm in the USA has been at a dead-end and that is about to
change. There has been no Flarm product in the USA, that is changing
with the import of the PowerFLARM device. The folks behind Flarm and
it's importers have specifically focused on delivering the PowerFLARM
product to the USA market that combines all the capabilities and
compatibility of FLARM with an ADS-B 1090ES traffic receiver.
PowerFLARM seems a very smart way for piltos to adopt FLARM today and
then move towards an ADS-B future.

Folks who've seen my ADS-B talks at PASCO seminars etc. will know I am
concerned about the adoption of Flarm devices. Concerned that people
invest in a Flarm protocol only device and then put off any ADS-B
future. Or that islands of Flarm adoption occur in some places, ADS-B
in others etc. and then in many years time we end up with
geographically/regionally fragmented adoption. I'm also concerned that
all these devices, especially anything ADS-B, is too complex for many
pilots to understand and I don't want to see pilots say buying an ADS-
B transceiver or a Flarm device thinking that is all they need for any
traffic scenario, or that it will make them visible to airliner TCAS,
etc. For these reasons I think the adoption of the PowerFLARM device
*with* 1090ES receiver capability and not a Flarm only device is the
correct way to go for the USA market.

Anecdotally there is really nobody I know who is seriously working on
installing pure ADS-B in gliders in the short term, however I know
several pilots who have already pre-ordered their PowerFLARM and
several clubs and FBOs thinking about fleet wide adoption. The serious
ADS-B "geeks" I know who are currently or wanting to run ADS-B data-
out with their Trig TT-21 seem to be mostly interested in doing so for
future use with a PowerFLARM ADS-B receiver.

To operate as an ADS-B traffic in the USA the glider will need an ADS-
B transmitter, as owners of a PowerFLARM want to do this they will
need to add a Mode S 1090ES transponder or upgrade their current Mode
S transponder or add a UAT transmitter or transceiver. If really low
cost GA targeted ADS-B transceivers do appear it may still make most
sense to just use the UAT transmitter part of that transceiver to send
the ADS-B location and to use the 1090ES receiver in the PowerFLARM
since it does the FLARM glider tuned traffic threat analysis, is
compatible with current glider cockpit displays etc. So to my mind
buying a PowerFLARM i the opposite to a dead-end, to me it is the
*only* viable ADS-B glider traffic receiver product on the market, and
you get a full FLARM-FLARM protocol device as well. Unless something
radical happens that I do not see, I expect PowerFLARM to be the most
common product over the next several years through which some early
adopter glider pilots will receive ADS-B traffic data in the USA. But
currently pricing for a full ADS-B system will keep those wanting to
use ADS-B down to early/bleeding edge adopters.

---

We seem to be focused here on glider-on-glider threats, I just want to
remind people that near dense airline and fast jet traffic a
transponder today is the only technology that provides both visibility
to ATC and compatibility with the TCAS systems carried by most those
airliners and jets. TCAS does not detect UAT ADS-B transmitters but
will see 1090ES transmitters (it sees the transponder). We need to be
really careful in promoting any technology as to what exact problem it
is good at solving. Remember the answer is 42, now if we could just
work out the question.

ADS-B has potential benefits such as long range tracking for SAR and
maybe contest tracking etc., precision "visibility" of/to GA aircraft
esp. outside current radar coverage, some long-range augmentation to
TCAS for visibility of gliders to airliners and fast jets etc. as
those aircraft deploy combined CDTI and TCAS systems etc. but by
itself it falls short at the two extremes of glider-on-glider
scenarios and airline-on-glider scenarios, yet these are the two
scenarios that ADS-B is often thought about for use in gliders. We
need to consider the appropriate use of Flarm, transponders (and PCAS
etc.) and ADS-B. No single one of these technologies really
effectively help addresses/minimize collisions threats through the
entire gamut of glider-on-glider through glider-on-GA to glider-on-
airliner and fast jet scenarios.

Darryl

On Aug 9, 9:23*am, brianDG303 wrote:
On Aug 9, 7:12*am, Renny wrote:
[snip]
Mike and Renny,
a good discussion of the macro view of FLARM and ADS-B. Another view
is more personal, for example in my situation- I fly a lot of ridge
and mountain in a very narrow altitude band and a lot of clouds. There
is not a lot of power traffic in those conditions. I have a
transponder but I don't see the Transmit light going off very often
and I suspect I am not getting very many radar paints down in the
rocks and trees where I like to fly. My greatest risk is from the six
other gliders I share the area with, which do not have transponders
and will never get them at the current costs; in fairness my threat to
them is even higher as I am a low hour pilot. FLARM would go a long
way to reducing the risks and at a reasonable cost; PowerFlarm would
be my choice as it would also provide protection from ADS-B and
transponder equipped threats, but at twice the cost the installed base
in my situation would be very much reduced and I stand a better chance
of talking my potentially deadly friends into investing in FLARM. 2020
is not soon enough. It is not soon enough for the pilots killed on a
regular basis at contests, which we seem to simply accept as an
unavoidable risk.

With that in mind Mike's statement that FLARM isn't of use (for me)
would not be correct. In 2004 my club lost two gliders and a pilot in
a collision that would not have happens if they had had FLARM. How do
you calculate that cost?

Brian

Brian & folks

Sorry to hog the thread but I want to make sure that key technical
facts are nailed down.

Brian wrote...

PowerFlarm would be my choice as it would also provide protection from ADS-B and
transponder equipped threats, ...

PowerFLARM or any other 1090ES receiver in the USA will "see" other
ADS-B data-out equipped traffic if and only if one or more of the
following is true

1. ADS-B Direct. That other traffic is transmitting ADS-B data-out on
the same physical link layer (i.e. a Mode S transponder with 1090ES
data-out).

or 2. ADS-R (ADS-B Relay). That other traffic is transmitting on the
other physical link layer (i.e. a UAT transmitter or transceiver)
*and* your aircraft is correctly transmitting ADS-B data-out that
describes the aircraft location and ADS-B receiver configuration (aka
the "capability code" bits)
*and* both aircraft are within range of one or more ADS-B ground
stations
*and* the aircraft are within the ADS-R "service volume" (or "threat
cylinder" in my terminology) of what I beleive is +/- 3,500' and 15
nautical miles of each other

---

If you don't meet *all* the requirments in #2 above your ADS-B
receiver may still see other traffic, especially traffic near other
ADS-B data-out equipped aircraft, but there is no gaurentee that you
will see all traffic near you. The PowerFLARM is not an ADS-B
transmitter so you will need a Mode S transponder with 1090ES data-out
or a UAT transmitter/receiver to make the ADS-B traffic part of the
PowerFLARM work properly. My expectation is given that ADS-B is a damn
confusing mess that at least for the next several years pilots in the
USA who buy a PowerFLARM will likely mostly do so for the flarm-flarm
and PCAS capability, and if they also see 1090ES data-out aircraft
(esp. airliners and fast jets) that great, but I do worry that many
pilots won't understand they will not properly see say GA UAT equipped
traffic without an ADS-B transmitter.

---

The PowerFLARM has PCAS capability so is the threat aircraft
transponder is being interrogated the PowerFLARM should be able to
warn you of a threat and its relative altitude but it won't have
direction information. The nice thing about this is many of us have
positive experiences with Zaon MRX units where there seems to be good
interrogation even outside of standard SSR coverage (via TCAS and TCAD
interrogators etc). However if the concern is about ridges and other
fairly obscured sites then there just may not be enough interrogations
to make a transponder useful for a PCAS (PowerFLARM or Zaon MRX etc.)
unit to detect anything. Of course if the threat aircraft has a Mode S
1090ES data-out transponder then the PowerFLARM will directly the ADS-
B data from the transponder.

PowerFLARM will also have ADS-B TIS-B support but it is not initially
shipping with this enabled. TIS-B is the relay of other aircraft SSR
position data to ADS-B equipped aircraft so they can "see" transponder
only equipped traffic.

TIS-B (ADS-B Traffic Information System) requires that the other
traffic has a Mode C or S transponder
*and* is within coverage of a traditional SSR radar (or
multilateration system). i.e. think airspace where you have ATC radar
coverage today.
*and* your aircraft is correctly transmitting ADS-B data-out that
describes the aircraft location and ADS-B receiver configuration (aka
the "capability code" bits)
*and* your aircraft is within range of an ADS-B ground station
*and* the threat aircraft is within the TIS-B "service volume" (or
"threat cylinder" in my terminology) of your aircraft - I believe that
is is +/- 3,500' and 15 nautical miles.

---

Since Brian mentioned ridges as a scenario, a potential concern there
is that you may be frequently outside of ADS-B ground coverage and
therefore ADS-R services may be unreliable or not work at all. So even
if all the gliders are properly equipped a 1090ES ADS-B equipped
glider just won't "see" a UAT equipped glider an visa versa. Although
ADS-B ground station coverage compared to traditional SSR radar is
going to be impressive, including at many locations down to very low
altitudes, ADS-B as deployed in the USA just is not designed to deal
with scenarios like ridge soaring. To deal reliably with this glider-
on-glider ridge scenario all gliders in that area would need to adopt
a single physical ADS-B link layer (UAT or 1090ES) and/or adopt
PowerFLARM (for Flarm-Flarm). This is one reason I also claim that ADS-
B alone in gliders is not practical in the USA until somebody develops
a low cost dual-link layer receiver that can receive directly on both
1090ES and UAT. The ADS-R overage is a reason that busy ridge soaring
locations might want to be looking at the ADS-B GBT (ground station)
coverage maps and getting a feel how much this will be issue in their
area. Something probably a good idea for the SSA to be pushing to have
happen/coordinate.

Sorry to ramble on but this level of detail is really unfortunately
necessary in discussing these technologies.

Darryl

On 8/9/2010 3:44 PM, Darryl Ramm wrote:
On Aug 9, 9:23 am, wrote:
On Aug 9, 7:12 am, wrote:
[snip]
Mike and Renny,
a good discussion of the macro view of FLARM and ADS-B. Another view
is more personal, for example in my situation- I fly a lot of ridge
and mountain in a very narrow altitude band and a lot of clouds. There
is not a lot of power traffic in those conditions. I have a
transponder but I don't see the Transmit light going off very often
and I suspect I am not getting very many radar paints down in the
rocks and trees where I like to fly. My greatest risk is from the six
other gliders I share the area with, which do not have transponders
and will never get them at the current costs; in fairness my threat to
them is even higher as I am a low hour pilot. FLARM would go a long
way to reducing the risks and at a reasonable cost; PowerFlarm would
be my choice as it would also provide protection from ADS-B and
transponder equipped threats, but at twice the cost the installed base
in my situation would be very much reduced and I stand a better chance
of talking my potentially deadly friends into investing in FLARM. 2020
is not soon enough. It is not soon enough for the pilots killed on a
regular basis at contests, which we seem to simply accept as an
unavoidable risk.

With that in mind Mike's statement that FLARM isn't of use (for me)
would not be correct. In 2004 my club lost two gliders and a pilot in
a collision that would not have happens if they had had FLARM. How do
you calculate that cost?

Brian

Brian& folks

Sorry to hog the thread but I want to make sure that key technical
facts are nailed down.

Brian wrote...

PowerFlarm would be my choice as it would also provide protection from ADS-B and
transponder equipped threats, ...

PowerFLARM or any other 1090ES receiver in the USA will "see" other
ADS-B data-out equipped traffic if and only if one or more of the
following is true

1. ADS-B Direct. That other traffic is transmitting ADS-B data-out on
the same physical link layer (i.e. a Mode S transponder with 1090ES
data-out).

or 2. ADS-R (ADS-B Relay). That other traffic is transmitting on the
other physical link layer (i.e. a UAT transmitter or transceiver)
*and* your aircraft is correctly transmitting ADS-B data-out that
describes the aircraft location and ADS-B receiver configuration (aka
the "capability code" bits)
*and* both aircraft are within range of one or more ADS-B ground
stations
*and* the aircraft are within the ADS-R "service volume" (or "threat
cylinder" in my terminology) of what I beleive is +/- 3,500' and 15
nautical miles of each other

---

If you don't meet *all* the requirments in #2 above your ADS-B
receiver may still see other traffic, especially traffic near other
ADS-B data-out equipped aircraft, but there is no gaurentee that you
will see all traffic near you. The PowerFLARM is not an ADS-B
transmitter so you will need a Mode S transponder with 1090ES data-out
or a UAT transmitter/receiver to make the ADS-B traffic part of the
PowerFLARM work properly. My expectation is given that ADS-B is a damn
confusing mess that at least for the next several years pilots in the
USA who buy a PowerFLARM will likely mostly do so for the flarm-flarm
and PCAS capability, and if they also see 1090ES data-out aircraft
(esp. airliners and fast jets) that great, but I do worry that many
pilots won't understand they will not properly see say GA UAT equipped
traffic without an ADS-B transmitter.

---

The PowerFLARM has PCAS capability so is the threat aircraft
transponder is being interrogated the PowerFLARM should be able to
warn you of a threat and its relative altitude but it won't have
direction information. The nice thing about this is many of us have
positive experiences with Zaon MRX units where there seems to be good
interrogation even outside of standard SSR coverage (via TCAS and TCAD
interrogators etc). However if the concern is about ridges and other
fairly obscured sites then there just may not be enough interrogations
to make a transponder useful for a PCAS (PowerFLARM or Zaon MRX etc.)
unit to detect anything. Of course if the threat aircraft has a Mode S
1090ES data-out transponder then the PowerFLARM will directly the ADS-
B data from the transponder.

PowerFLARM will also have ADS-B TIS-B support but it is not initially
shipping with this enabled. TIS-B is the relay of other aircraft SSR
position data to ADS-B equipped aircraft so they can "see" transponder
only equipped traffic.

TIS-B (ADS-B Traffic Information System) requires that the other
traffic has a Mode C or S transponder
*and* is within coverage of a traditional SSR radar (or
multilateration system). i.e. think airspace where you have ATC radar
coverage today.
*and* your aircraft is correctly transmitting ADS-B data-out that
describes the aircraft location and ADS-B receiver configuration (aka
the "capability code" bits)
*and* your aircraft is within range of an ADS-B ground station
*and* the threat aircraft is within the TIS-B "service volume" (or
"threat cylinder" in my terminology) of your aircraft - I believe that
is is +/- 3,500' and 15 nautical miles.

---

Since Brian mentioned ridges as a scenario, a potential concern there
is that you may be frequently outside of ADS-B ground coverage and
therefore ADS-R services may be unreliable or not work at all. So even
if all the gliders are properly equipped a 1090ES ADS-B equipped
glider just won't "see" a UAT equipped glider an visa versa. Although
ADS-B ground station coverage compared to traditional SSR radar is
going to be impressive, including at many locations down to very low
altitudes, ADS-B as deployed in the USA just is not designed to deal
with scenarios like ridge soaring. To deal reliably with this glider-
on-glider ridge scenario all gliders in that area would need to adopt
a single physical ADS-B link layer (UAT or 1090ES) and/or adopt
PowerFLARM (for Flarm-Flarm). This is one reason I also claim that ADS-
B alone in gliders is not practical in the USA until somebody develops
a low cost dual-link layer receiver that can receive directly on both
1090ES and UAT. The ADS-R overage is a reason that busy ridge soaring
locations might want to be looking at the ADS-B GBT (ground station)
coverage maps and getting a feel how much this will be issue in their
area. Something probably a good idea for the SSA to be pushing to have
happen/coordinate.

Sorry to ramble on but this level of detail is really unfortunately
necessary in discussing these technologies.

Darryl

I'm glad you posted this very informative item. As you point out, this
is an incredible mess. It didn't need to be that way, but that's what
you get with government engineering by political committee.

It's too bad that the FLARM guys didn't go after the US market when they
1st started their project in Europe years ago. It might have taken off
in the US GA market and created a defacto standard. No we have a huge
mess with no good answers in sight.

Certainly not a story that gets people excited about spending $$$$s to
upgrade their avionics.

--
Mike Schumann

On 8/9/2010 9:12 AM, Renny wrote:
On Aug 9, 7:56 am, Mike
wrote:
On 8/9/2010 8:43 AM, Steve Freeman wrote:

Curious about the use of Flarm in the US. Was told by another pilot
that the frequency used by Flarm is not approved for that category of
use in the US. Is that true? If it is, do they make units that use a
US approved frequency?

There is virtually no FLARM in the US. It is unlikely to take off here,
as the biggest threats for mid-airs in the US are between powered
aircraft and gliders or other aircraft.

It's a chicken and egg situation. FLARM is only interesting if everyone
equips. No one is going to equip if they don't think that everyone else
will.

With ADS-B coming out, that is the way to go in the US. If you buy an
ADS-B transceiver, not only will you see other ADS-B equipped aircraft,
but, if you are within range of an ADS-B ground station, you will also
see all Mode C/S transponder equipped aircraft that are visible to ATC.
With 80-90% of GA aircraft in the US transponder equipped, this gives
an immediate benefit to anyone investing in ADS-B (assuming that they
have a ground station deployed in their area).

--
Mike Schumann

Mike,
Your points are all well taken. I realize that FLARM has never been
accepted in the US up to now, and we all know that ADS-B is coming in
2020 (although I thought there was a "glider" exemption), but with
that being said, would it make any sense for FLARM units to be
required for gliders competing in any of our nationals (or maybe even
in regionals)?

As you are aware, we've had several mid-airs between gliders in recent
years and perhaps if gliders had been equipped with FLARM units in a
nationals or in a regionals, some of these mid-airs might have been
prevented.....Just a thought!

Thanks - Renny

Why not require ADS-B units instead. Then you'd get the advantages of
FLARM, but you'd also see all of the transponder equipped GA aircraft
(assuming that there was a ground station in the area).

Now that Navworx is shipping their unit, this could happen tomorrow.
I'm sure that someone could talk Navworx into working with the major
glide computer manufacturers to provide the necessary interfaces if they
knew that this would be worth their while.

--
Mike Schumann

On Aug 9, 9:45*am, Mike Schumann
wrote:

Why not require ADS-B units instead. *Then you'd get the advantages of
FLARM, but you'd also see all of the transponder equipped GA aircraft
(assuming that there was a ground station in the area).

Perhaps because glider pilots would be overwhelmed by nuissance alerts
when contest flying? I have already experienced my PCAS becoming
close to useless as more gliders are fitted with transponders. I
don't need another system crying wolf all the time.

FLARM uses intelligent alerting based on glider flight
characteristics. It has been reported that the nuissance alerting
frequency low enough that it is still useful in high glider traffic
densities.


Andy

On 8/9/2010 11:57 AM, Andy wrote:
On Aug 9, 9:45 am, Mike
wrote:

Why not require ADS-B units instead. Then you'd get the advantages of
FLARM, but you'd also see all of the transponder equipped GA aircraft
(assuming that there was a ground station in the area).

Perhaps because glider pilots would be overwhelmed by nuissance alerts
when contest flying? I have already experienced my PCAS becoming
close to useless as more gliders are fitted with transponders. I
don't need another system crying wolf all the time.

FLARM uses intelligent alerting based on glider flight
characteristics. It has been reported that the nuissance alerting
frequency low enough that it is still useful in high glider traffic
densities.


Andy


There are two parts to FLARM; an ADS-B type position reporting
broadcast function, and a built in collision warning system.

ADS-B transceivers typically do not include any collision warning logic.
Instead they are more like modems. They transmit and receive position
data in addition to receiving weather info, etc. This information is
passed on to some form of graphics display device so that the locations
of other aircraft can be shown on a moving map display relative to your
own aircraft.

The display device, in addition to showing the location of other
aircraft, can also be programmed to provide collision warnings.
Obviously, the typical flight trajectories of gliders are different than
most power aircraft. I suspect that most glider specific moving map
vendors will try to match FLARM's logic to minimize false alarms if they
elect to provide a collision warning function in addition to just
displaying the relative locations of other aircraft.

ADS-B is obviously just in its infancy in the US vs FLARM's development
in Europe. The encouraging news is that the potential size of the US
ADS-B market is much larger than the potential FLARM market in Europe
(when you include the GA power market), so there will undoubtedly be
lots of innovation in the display devices that will provide the
collision warning function. In VFR environments, these devices will not
require FAA approvals, so I expect that technical advancements will be
very rapid, once low cost ADS-B transceivers become widely available.

--
Mike Schumann

Andy is exactly right. The big deal that is Flarm is not the
hardware and the radio signal mechanisms it is the algorithms and the
decision logic that is responding to the air interface. I would be
willing to bet that the Flarm folks have put 90% of their engineering
efforts on refining and perfecting the response logic as compared to
10% for all the rest of the design. In the US we are extremely
fortunate that this work has already been done. There has been years
of refinement effort that has been done specifically for soaring. An
ADS-B unit primarily designed for power planes (as they all are) will
not be satisfactory for glider - glider protection.

In my view, the new PowerFlarm unit is a brilliant solution to the
problem. It allows US pilots to piggy-back the tremendous amount of
effort expended to perfect Flarm in Europe. It provides the PCAS type
function to help protect against putt-putt traffic and it also
provides the ADS-B receive technology so that it can be used as a big
chunk of the ADS-B solution as that becomes more widely adopted in the
out years.

We must adopt PowerFlarm technology for the 2011 racing season in the
US. There is no chicken and egg problem when it is a requirement for
entry in all sanctioned contests. I plead for support from every
racing pilot on this. There was a midair at the last two contests
that I attended. There has also been a midair at the last two
contests that I attended at Uvalde. The crash at Uvlade last week
was highly disconcerting to me. Chris was a great guy. Even though
I was doing well in the contest, I just went home. I was intending
not to return to the sport ever again. If we can make racing safer
with rule and procedure changes and with immediate adoption of Power
Flarm, I hope that I will be able to change my mind.

Andy --

I'm unable to load the FLARM web page to investigate, but I'm curious
about "intelligent alerting based on glider flight characteristics."
Can you (or anyone) confirm that PowerFLARMs would have detected (and
warned) last week's head-on in Uvalde?

What glider flight characteristics in particular play into FLARM's
algorithms?

~ted/2NO

On Aug 9, 9:45*am, Mike Schumann
wrote:
On 8/9/2010 9:12 AM, Renny wrote:

On Aug 9, 7:56 am, Mike
wrote:
On 8/9/2010 8:43 AM, Steve Freeman wrote:

Curious about the use of Flarm in the US. Was told by another pilot
that the frequency used by Flarm is not approved for that category of
use in the US. Is that true? If it is, do they make units that use a
US approved frequency?

There is virtually no FLARM in the US. *It is unlikely to take off here,
as the biggest threats for mid-airs in the US are between powered
aircraft and gliders or other aircraft.

It's a chicken and egg situation. *FLARM is only interesting if everyone
equips. *No one is going to equip if they don't think that everyone else
will.

With ADS-B coming out, that is the way to go in the US. *If you buy an
ADS-B transceiver, not only will you see other ADS-B equipped aircraft,
but, if you are within range of an ADS-B ground station, you will also
see all Mode C/S transponder equipped aircraft that are visible to ATC..
* *With 80-90% of GA aircraft in the US transponder equipped, this gives
an immediate benefit to anyone investing in ADS-B (assuming that they
have a ground station deployed in their area).

--
Mike Schumann

Mike,
Your points are all well taken. I realize that FLARM has never been
accepted in the US up to now, and we all know that ADS-B is coming in
2020 (although I thought there was a "glider" exemption), but with
that being said, would it make any sense for FLARM units to be
required for gliders competing in any of our nationals (or maybe even
in regionals)?

As you are aware, we've had several mid-airs between gliders in recent
years and perhaps if gliders had been equipped with FLARM units in a
nationals or in a regionals, some of these mid-airs might have been
prevented.....Just a thought!

Thanks - Renny

Why not require ADS-B units instead. *Then you'd get the advantages of
FLARM, but you'd also see all of the transponder equipped GA aircraft
(assuming that there was a ground station in the area).

Now that Navworx is shipping their unit, this could happen tomorrow.
I'm sure that someone could talk Navworx into working with the major
glide computer manufacturers to provide the necessary interfaces if they
knew that this would be worth their while.

--
Mike Schumann

Mike

You are back again proposing the same NavWorx ADS-B transceiver for
glider cockpits that was discussed recently and just does not look
practical for our needs. While I'd love to see products that do meet
our needs, unfortunately there are currently no available UAT
transceivers that do appear suitable for use in gliders and none that
I am aware of that are coming in the near term that will change this.
Anybody able to share any different information?

So I'll repeat below again the issues with the NavWorx ADS600-B. Until
an ADS-B transceiver addresses these issues I don't see how it can
hope to have any wide adoption in glider cockpits.

---

1. The specified 0.8 Amp (scaled to @12V) power draw the Navworx
ADS600-B ADS-B transceiver is just too much to be interesting for most
glider cockpits. Do you have different information on the actual power
draw? This is the receiver box alone and today a display would need to
be added increasing this power consumption.

2. (A) The NavWorx does not support the FLARM serial display protocol
so is not compatible with most current PDA/PNA soaring software and
flight computers (e.g. the ClearNav) that all support the FLARM
display protocol. Navworx could implement this, and I've talked to
them about this, but it does not seem to be something they are
interested in doing now. With a current device with power consumption
that just does not fit what we need it would not seem to make business
sense for them to target delivering a glider specific display
protocol. It might make more sense combined with a future lower-power
consumption version of their devices. Given they are a small company
and just have their first transceiver going into the market I'd not
hold my breath. Their transceiver will likely be interesting for the
lower-end of the GA market who have older panels with Mode C
transponders and who do not have a Mode S transponder upgradable to
1090ES data-out, they really need TSO approval for the product to be
successful in the GA market and I kind of expect that is where their
resources are focused.

2 (B) The NavWorx and many other ADS-B receivers has no built-in
traffic warning or traffic filtering algorithms so won't itself warn
about traffic. It relies on the external display system to do this.
None of these systems available are tuned for gliders, i.e. provide
the type of threat detection and false alarm prevention required in
many glider situations, especially when thermalling in gaggles (likely
one of the contest scenarios worrying many people). And it is not just
a matter of working to connect the ADS-B box to existing gliding
software or flight computers. Those systems today support the Flarm
serial protocol - in this scheme the traffic threat processing is done
within the Flarm (or PowerFLARM) box, with a NavWorx receiver
connected that gliding software or flight computer will need to do the
threat assessment and false alarm prevention etc. itself. Having said
that I believe some of these soaring software and flight computer
vendors should be working to support basic display of ADS-B traffic
(and FIS-B weather etc.) -- this may make sense for example where ADS-
B is being used as an adjunct to a transponder in busy GA traffic
areas. I've actively tried to encourage some of those ADS-B and
soaring products vendors to play together for this reason. However I'm
just not sure those vendors would want to step up and do the FLARM
style traffic threat detection. Especially since most of their market
that cares about traffic warning is already using Flarm.

2 (C) The Flarm serial display protocol combines aircraft GPS location
and traffic data into a single serial stream so that one serial port
on a PDA or flight computer can receive both data. Other popular
display protocol used for ADS-B traffic display like the Garmin TIS
protocol does not do this and would require a separate serial port for
GPS position data and for traffic data or some external third party
hardware box to combine two serial ports. This won't be an issue for
everybody but I suspect will be a problem for a significant number of
pilots. Just adding support in the PDA or flight computer software for
one of these other display protocols does not change this problem. You
really need the ADS-B receiver product to support the Flarm serial
display protocol for the product to be easily usable in a wide range
of glider cockpits.

3. Cost. At US$2,495 list the NavWorx ADS600-B ADS-B transceiver is
significantly more expensive than a PowerFlarm (~$US1,695 list) by
itself (for it's Flarm to Flarm capability). When you factor in costs
of a display for the ADS-B and other components it is in the ball park
of say a PowerFLARM + Trig TT21 which can do ADS-B data-out. The TT-21
with 1090ES data or out or a similar 1090ES transponder, or even a UAT
transmitter, is required to have the PowerFLARM ADS-B receiver work
properly in the USA. (And technically unless you want to add a
currently expensive GPS receiver the TT21 cannot meet the 2020
mandatory ADS-B data-out requirements, but neither will the currently
non-TSO ADS600-B, but lucky we don't need to meet those requirements
for gliders). I think current ADS-B prices for an actual working
system of around $3k and more price it out of most glider cockpits
even if it actually did what was needed to help with the glider-on-
glider threat. While prices may fall over time I'd not hold my breath
for a radical reduction, I suspect current vendors are meeting early
adopter needs in the GA market and there won't be a lot of movement on
pricing until we get closer to 2020.

---

The Mitre UAT transceiver prototype while it should have low power
consumption compared to the Navworx ADS600-B it is just a prototype
and AFAIK has the other problems described above. I am happy seeing an
R&D platform and prototype device being developed and hopefully used
to work on issues relevant to ADS-B in gliders but it is a long way
from that to something Mitre or others can convince a manufacture to
want to make (effectively for the USA gliding community only, yikes
that's a small market) and then to something we can buy. And I'm not
really sure Mitre or anybody else are addressing the needs or the
glider cockpit. If they were the prototype would already have things
like serial FLARM support and threat assessment etc. handled on-board.
That is just such an obvious requirement for the gilder market.

Darryl

On 8/9/2010 12:55 PM, Darryl Ramm wrote:
On Aug 9, 9:45 am, Mike
wrote:
On 8/9/2010 9:12 AM, Renny wrote:

On Aug 9, 7:56 am, Mike
wrote:
On 8/9/2010 8:43 AM, Steve Freeman wrote:

Curious about the use of Flarm in the US. Was told by another pilot
that the frequency used by Flarm is not approved for that category of
use in the US. Is that true? If it is, do they make units that use a
US approved frequency?

There is virtually no FLARM in the US. It is unlikely to take off here,
as the biggest threats for mid-airs in the US are between powered
aircraft and gliders or other aircraft.

It's a chicken and egg situation. FLARM is only interesting if everyone
equips. No one is going to equip if they don't think that everyone else
will.

With ADS-B coming out, that is the way to go in the US. If you buy an
ADS-B transceiver, not only will you see other ADS-B equipped aircraft,
but, if you are within range of an ADS-B ground station, you will also
see all Mode C/S transponder equipped aircraft that are visible to ATC.
With 80-90% of GA aircraft in the US transponder equipped, this gives
an immediate benefit to anyone investing in ADS-B (assuming that they
have a ground station deployed in their area).

--
Mike Schumann

Mike,
Your points are all well taken. I realize that FLARM has never been
accepted in the US up to now, and we all know that ADS-B is coming in
2020 (although I thought there was a "glider" exemption), but with
that being said, would it make any sense for FLARM units to be
required for gliders competing in any of our nationals (or maybe even
in regionals)?

As you are aware, we've had several mid-airs between gliders in recent
years and perhaps if gliders had been equipped with FLARM units in a
nationals or in a regionals, some of these mid-airs might have been
prevented.....Just a thought!

Thanks - Renny

Why not require ADS-B units instead. Then you'd get the advantages of
FLARM, but you'd also see all of the transponder equipped GA aircraft
(assuming that there was a ground station in the area).

Now that Navworx is shipping their unit, this could happen tomorrow.
I'm sure that someone could talk Navworx into working with the major
glide computer manufacturers to provide the necessary interfaces if they
knew that this would be worth their while.

--
Mike Schumann

Mike

You are back again proposing the same NavWorx ADS-B transceiver for
glider cockpits that was discussed recently and just does not look
practical for our needs. While I'd love to see products that do meet
our needs, unfortunately there are currently no available UAT
transceivers that do appear suitable for use in gliders and none that
I am aware of that are coming in the near term that will change this.
Anybody able to share any different information?

So I'll repeat below again the issues with the NavWorx ADS600-B. Until
an ADS-B transceiver addresses these issues I don't see how it can
hope to have any wide adoption in glider cockpits.

---

1. The specified 0.8 Amp (scaled to @12V) power draw the Navworx
ADS600-B ADS-B transceiver is just too much to be interesting for most
glider cockpits. Do you have different information on the actual power
draw? This is the receiver box alone and today a display would need to
be added increasing this power consumption.

2. (A) The NavWorx does not support the FLARM serial display protocol
so is not compatible with most current PDA/PNA soaring software and
flight computers (e.g. the ClearNav) that all support the FLARM
display protocol. Navworx could implement this, and I've talked to
them about this, but it does not seem to be something they are
interested in doing now. With a current device with power consumption
that just does not fit what we need it would not seem to make business
sense for them to target delivering a glider specific display
protocol. It might make more sense combined with a future lower-power
consumption version of their devices. Given they are a small company
and just have their first transceiver going into the market I'd not
hold my breath. Their transceiver will likely be interesting for the
lower-end of the GA market who have older panels with Mode C
transponders and who do not have a Mode S transponder upgradable to
1090ES data-out, they really need TSO approval for the product to be
successful in the GA market and I kind of expect that is where their
resources are focused.

2 (B) The NavWorx and many other ADS-B receivers has no built-in
traffic warning or traffic filtering algorithms so won't itself warn
about traffic. It relies on the external display system to do this.
None of these systems available are tuned for gliders, i.e. provide
the type of threat detection and false alarm prevention required in
many glider situations, especially when thermalling in gaggles (likely
one of the contest scenarios worrying many people). And it is not just
a matter of working to connect the ADS-B box to existing gliding
software or flight computers. Those systems today support the Flarm
serial protocol - in this scheme the traffic threat processing is done
within the Flarm (or PowerFLARM) box, with a NavWorx receiver
connected that gliding software or flight computer will need to do the
threat assessment and false alarm prevention etc. itself. Having said
that I believe some of these soaring software and flight computer
vendors should be working to support basic display of ADS-B traffic
(and FIS-B weather etc.) -- this may make sense for example where ADS-
B is being used as an adjunct to a transponder in busy GA traffic
areas. I've actively tried to encourage some of those ADS-B and
soaring products vendors to play together for this reason. However I'm
just not sure those vendors would want to step up and do the FLARM
style traffic threat detection. Especially since most of their market
that cares about traffic warning is already using Flarm.

2 (C) The Flarm serial display protocol combines aircraft GPS location
and traffic data into a single serial stream so that one serial port
on a PDA or flight computer can receive both data. Other popular
display protocol used for ADS-B traffic display like the Garmin TIS
protocol does not do this and would require a separate serial port for
GPS position data and for traffic data or some external third party
hardware box to combine two serial ports. This won't be an issue for
everybody but I suspect will be a problem for a significant number of
pilots. Just adding support in the PDA or flight computer software for
one of these other display protocols does not change this problem. You
really need the ADS-B receiver product to support the Flarm serial
display protocol for the product to be easily usable in a wide range
of glider cockpits.

3. Cost. At US$2,495 list the NavWorx ADS600-B ADS-B transceiver is
significantly more expensive than a PowerFlarm (~$US1,695 list) by
itself (for it's Flarm to Flarm capability). When you factor in costs
of a display for the ADS-B and other components it is in the ball park
of say a PowerFLARM + Trig TT21 which can do ADS-B data-out. The TT-21
with 1090ES data or out or a similar 1090ES transponder, or even a UAT
transmitter, is required to have the PowerFLARM ADS-B receiver work
properly in the USA. (And technically unless you want to add a
currently expensive GPS receiver the TT21 cannot meet the 2020
mandatory ADS-B data-out requirements, but neither will the currently
non-TSO ADS600-B, but lucky we don't need to meet those requirements
for gliders). I think current ADS-B prices for an actual working
system of around $3k and more price it out of most glider cockpits
even if it actually did what was needed to help with the glider-on-
glider threat. While prices may fall over time I'd not hold my breath
for a radical reduction, I suspect current vendors are meeting early
adopter needs in the GA market and there won't be a lot of movement on
pricing until we get closer to 2020.

---

The Mitre UAT transceiver prototype while it should have low power
consumption compared to the Navworx ADS600-B it is just a prototype
and AFAIK has the other problems described above. I am happy seeing an
R&D platform and prototype device being developed and hopefully used
to work on issues relevant to ADS-B in gliders but it is a long way
from that to something Mitre or others can convince a manufacture to
want to make (effectively for the USA gliding community only, yikes
that's a small market) and then to something we can buy. And I'm not
really sure Mitre or anybody else are addressing the needs or the
glider cockpit. If they were the prototype would already have things
like serial FLARM support and threat assessment etc. handled on-board.
That is just such an obvious requirement for the gilder market.

Darryl



We currently already have a Rube Goldberg ADS-B strategy in the US where
we have two competing flavors of ADS-B, no strategy to get rid of
conventional transponders, and now we've got somebody advocating adding
FLARM to the mix for a VERY small subset of aircraft population. This
is going to solve all of our problems?????

The only long term solution is to get everyone (gliders, GA, airliners,
balloons, parachutists, UAVs, etc.....) to standardize on a single
collision avoidance technology. We had the golden opportunity to do
that with ADS-B UAT, but the FAA has totally screwed that up, and now
everyone is going off into a thousand different directions.

The FLARM guys didn't help either. Years ago, when FLARM 1st came out,
they specifically prohibited the use of their equipment in the US. If
they hadn't done that, maybe FLARM would have taken off here in parallel
with Europe and become a defacto standard for the GA community.

They also could have taken their hardware platform and come out with a
US version that conformed to the ADS-B UAT frequency and protocol
standards. For whatever reason, they weren't interested in that either.

Maybe the best solution is for the SSA to buy 50 basic FLARM boxes and
rent them out to contests to use in the short term and wait for the FAA
and the market to sort things out over the next 20 years.

My suggestion is to forget about contests and use OLC if you need a fix
for your competitive urges.

--
Mike Schumann