FLARM

Martin Gregorie wrote:
Its a nice thought, but one-size-fits-all would most likely attract all
the glider pilot bitching about power consumption, size and price that's
currently directed at transponders and ADS-B.

There's one simple reason for this: a universal solution would also need
to be applicable to faster aircraft and would have to radiate
proportionately more power. A system that would give the same avoidance
time against a 250 kt airliner as for a 100 kt glider would need 2.5
times the range and hence must radiate 6.25 times as much power.
Suddenly your 100 mA FALARM equivalent is eating 625 mA.

In practice a universal device would burn a LOT more power than I just
calculated because:
- the worst case warning range for two 250 kt aircraft is 42% more than
I calculated above, so the transmission power is doubled.
- airlines would want a longer avoidance period than we need.
- the range requirement at least doubles again (and transmission power
quadruples) when you consider jet transports at full cruising speed
above 10,000 ft or fast jets at any altitude?

Which is why ADS-B exists (in the US, and Australia now, I believe) in
two forms. An ICAO-approved Mode S "squitter" is basically layered on
top of a Mode S transponder, and has similar power requirements. A
Universal Access Transceiver (UAT) is intended for use by lower slower
aircraft (like gliders), and has significantly lower power requirements.
A network of ground stations provides the interface between ATC, Mode
S squitter, and UAT equipped aircraft...

Marc

http://www.users.bigpond.com/keepits...sidy_NSWGA.doc

If interested reed the last page titled Why Flarm

also

http://www.rf-developments.com/page008.html

cheers

paul


Eric Greenwell wrote:
PB wrote:

The Australian Flarm (I am not sure about the European version) will
be able to receive communication from transponders and thus give
information on the power aircraft.


Can you point to a website that discusses this? If it's true, it's very
interesting, because the transponder detectors available aren't much
cheaper than FLARM, and can't supply a GPS signal to navigation
computers, or make a flight log. It would make FLARM a good value even
if no other glider had one.

At 06:54 10 March 2006, Pb wrote:
http://www.users.bigpond.com/keepits...mg/Flarm_Subsi
dy_NSWGA.doc

If interested reed the last page titled Why Flarm

Yes I have. The letter claims a 70% reduction in collisions.
Can you tell me where I can see the data that supports
this claim please, if it is true it would negate many
of my arguments.

also

http://www.rf-developments.com/page008.html

From the above document: Note: This system requires
other gliders to be fitted with a unit for it to work,
we do not sense transponder equipped traffic. We accept
no responsibility for its operation, this system will
never replace primary SEE and AVOID techniques. OzFLARM
is an aid for traffic awareness as well as providing
other handy features such as back up logger for comps
etc. The USER of OZFLARM accepts full responsibility
for good airmanship and acknowledges that OzFLARM is
not intended to replace lookout!

That is what is called a get out clause. Will pilots
look at it in the same way though?

cheers

paul


Eric Greenwell wrote:
PB wrote:

The Australian Flarm (I am not sure about the European
version) will
be able to receive communication from transponders
and thus give
information on the power aircraft.


Can you point to a website that discusses this? If
it's true, it's very
interesting, because the transponder detectors available
aren't much
cheaper than FLARM, and can't supply a GPS signal
to navigation
computers, or make a flight log. It would make FLARM
a good value even
if no other glider had one.

"Don Johnstone" wrote in message
...
From the above document: Note: This system requires
other gliders to be fitted with a unit for it to work,
we do not sense transponder equipped traffic. We accept
no responsibility for its operation, this system will
never replace primary SEE and AVOID techniques. OzFLARM
is an aid for traffic awareness as well as providing
other handy features such as back up logger for comps
etc. The USER of OZFLARM accepts full responsibility
for good airmanship and acknowledges that OzFLARM is
not intended to replace lookout!

That is what is called a get out clause. Will pilots
look at it in the same way though?

I would call that a common sense clause :-)

However, pilots not looking at it in the same way shouldn't fly gliders in
the first place...

Marc Ramsey wrote:
Martin Gregorie wrote:
Its a nice thought, but one-size-fits-all would most likely attract
all the glider pilot bitching about power consumption, size and price
that's currently directed at transponders and ADS-B.

There's one simple reason for this: a universal solution would also
need to be applicable to faster aircraft and would have to radiate
proportionately more power. A system that would give the same
avoidance time against a 250 kt airliner as for a 100 kt glider would
need 2.5 times the range and hence must radiate 6.25 times as much
power. Suddenly your 100 mA FALARM equivalent is eating 625 mA.

In practice a universal device would burn a LOT more power than I just
calculated because:
- the worst case warning range for two 250 kt aircraft is 42% more than
I calculated above, so the transmission power is doubled.
- airlines would want a longer avoidance period than we need.
- the range requirement at least doubles again (and transmission power
quadruples) when you consider jet transports at full cruising speed
above 10,000 ft or fast jets at any altitude?

Which is why ADS-B exists (in the US, and Australia now, I believe) in
two forms. An ICAO-approved Mode S "squitter" is basically layered on
top of a Mode S transponder, and has similar power requirements. A
Universal Access Transceiver (UAT) is intended for use by lower slower
aircraft (like gliders), and has significantly lower power requirements.
A network of ground stations provides the interface between ATC, Mode S
squitter, and UAT equipped aircraft...

As a matter of interest, how is the ground station network paid for? Is
it added into the UAT purchase price, an annual subscription, or does
the general taxpayer pick up the tab?

I'm not grinding axes, just curious.

--
martin@ | Martin Gregorie
gregorie. | Essex, UK
org |

Neither link was posted as an argument to support Flarm, rather a reply
to Eric G for information regarding the integration between Flarm and
other transponders.

Paul

Don Johnstone wrote:
At 06:54 10 March 2006, Pb wrote:

http://www.users.bigpond.com/keepits...mg/Flarm_Subsi

dy_NSWGA.doc

If interested reed the last page titled Why Flarm


Yes I have. The letter claims a 70% reduction in collisions.
Can you tell me where I can see the data that supports
this claim please, if it is true it would negate many
of my arguments.

also

http://www.rf-developments.com/page008.html


From the above document: Note: This system requires
other gliders to be fitted with a unit for it to work,
we do not sense transponder equipped traffic. We accept
no responsibility for its operation, this system will
never replace primary SEE and AVOID techniques. OzFLARM
is an aid for traffic awareness as well as providing
other handy features such as back up logger for comps
etc. The USER of OZFLARM accepts full responsibility
for good airmanship and acknowledges that OzFLARM is
not intended to replace lookout!

That is what is called a get out clause. Will pilots
look at it in the same way though?

cheers

paul


Eric Greenwell wrote:

PB wrote:


The Australian Flarm (I am not sure about the European
version) will
be able to receive communication from transponders
and thus give
information on the power aircraft.


Can you point to a website that discusses this? If
it's true, it's very
interesting, because the transponder detectors available
aren't much
cheaper than FLARM, and can't supply a GPS signal
to navigation
computers, or make a flight log. It would make FLARM
a good value even
if no other glider had one.

PB wrote:
http://www.users.bigpond.com/keepits...sidy_NSWGA.doc


If interested reed the last page titled Why Flarm

That is intriguing: it says FLARM will be able to sense ADSB units, but
not transponders. Where are the modules mentioned available or
discussed? I can't find mention of them on the FLARM site or the RF Dev
elopements site. Not that there is any hurry, given the limited
deployment of ADSB.


also

http://www.rf-developments.com/page008.html

This states their unit can not sense transponders, a disappointment, but
I'm not surprised. It's an different technology on a different frequency
band.

--
Change "netto" to "net" to email me directly

Eric Greenwell - Washington State, USA

www.motorglider.org - Download "A Guide to Self-launching Sailplane
Operation"

I can imagine Don appying the same reasoning shortly after the the invention
the telephone, the car, the radio, the radio, email and probably the wheel.

The price of a FLARM is trivial when compared with the cost of owning and
operating a glider (even an old one). Personally I go with the principle
that "every little helps" as the monkey said.

New technology is always driven by early adopters - the Dons of the world
catch up a fews years later - remember the early debates over GPS and PDAs
(some still ongoing).

FLARM is a partial solution to a problem that may be better solved by other
technologies in the future. While I'm waiting, I prefer to get whatever
benefit I can from something that's available today at very modest cost.

"Don Johnstone" wrote in message
...
I think Tim in his reply to my post highlighted the
biggest failing in FLARM, lack of interest by the majority.
Having a FLARM in your glider is totally useless unless
eveyone else has one in theirs, and the only way to
achieve that is by compulsion.
Anyone who thinks that the majority of pilots will
fit one voluntarily is deluding themselves.
Right now in most of the world FLARM is just a useless
expensive piece of electronics and unless fitting it
becomes compulsory it will go the same way as Betamax
video tapes.

In answer to Bert my panel is full of instruments which
are of some use to me.






At 13:42 06 March 2006, Guy Acheson wrote:
I am glad the origens of FLARM have come up because
it answers some of my questions. I have flown in the
southern Alps and their environment for flight is unlike
any I know of in the USA or Australia. Flying in the
southern Alps many days consists of HUNDREDS of gliders
flying below peak height in all directions throughout
a mountain range that has valleys and passes in all
directions. Flying out of St Auban last year we were
using wrecked gliders as landmarks for navigation.
Collision avoidance is a very high energy activity
in that airspace. Power traffic is virtually non-existant
in that airspace. The power people just fly high above
all the mountains and valleys.

Here in the USA our most common partners in the airspace
are power planes. Power planes have transponders.
I fly out of Minden, NV and for years had fairly regular
close encounters with power planes. Commercial planes
coming in and out of Reno would turn right at you,
your flight path goes accross standard flight paths
in and out of Reno. Military traffic was especially
scary with fighters and heavies just dropping out of
the cloud deck right on top of me or directly in my
flight path. Then I installed a transponder and my
experiences are very different. I monitor the air
traffic people while flying and am very impressed how
well they see me and warn power traffic of my presence.
Commercial planes know where I am and no longer turn
into me. If our paths will cross the power planes
alter their altitude.

As for people being worried about battery problems,
that is just whining. I fly with a radio, transponder,
encoder, Cambridge, and iPAQ using a 12 amp hour battery.
I have never had a problem flying up to six hours.
I take that back. I had a problem for a couple weeks
and it turned out to be a bad battery charger.

For the USA I really believe that installing a transponder
is the responsible thing to do for all air traffic.
Wings and Wheels sells a unit that sounds a lot like
the FLARM but recognizes transponders. It makes much
more sense to me to go with the technology that has
the largest installed base, equipment availability
and support.


At 12:48 06 March 2006, Bert Willing wrote:
Either you don't know what you are talking about (ever
seen the external
Flarm display?), or your panel is crap.

'Don Johnstone' wrote in message
...
I do not have room on my panel for any additional
display

Tim Newport-Peace wrote:

It came to my attention today, that one insurer in Europe is offering a
10% discount to FLARM users.


The Swiss Pool of Aviation Insurances supported the develpment of FLARM
already in 2004.
see www.flarm.com/news/index_en.html
Swiss insurances are usually pretty good in financial calculation and do
not like to waste money.

regards
Bear

Eric Greenwell wrote:
Mal wrote:
Perhaps the Australians would be willing to sell us units?


Yeah we could chuck in a few bags of wheat as well.
http://rf-developments.com/page008.html

We have quite a bit of wheat already, but maybe a few bottles of Shiraz?
The big ones?


There is no such thing as a 'small' Australian Shiraz!
:-)