Making a Glider Easier to See in the Air

Please educate me on FLARM.
Does it spot individuals or just that one is nearby?
A contest "minnow pack" would be alarming each other all the time, if it
does not count individuals.
Thanks

--
Hartley Falbaum

wrote in message
oups.com...
Jim,

Where I've been flying lately (Southern Illinois, East of St Louis) I
can probably count the gliders within 100 km of me on any given day on
the fingers of one hand - and most of those are trainers in the
pattern!. OTOH, I see lightplanes droning along pretty much at my
altitude all the time. So FLARM would be pretty useless, while a
transponder detector would be nice (I'm waiting for one that is small,
reliable, and has an aural cue).

Europe, on the other hand, has a lot of gliders crammed into tight
airspace, but relatively fewer VFR bugsmashers not talking to anyone.
So FLARM becomes a real player.

Now having all contestants carry FLARM at a big US regional or better
contest - that could be useful. Not likely, though, if the ELT example
is anything to judge by!

Kirk
66

And now, for some light hearted tom-foolery!

It strike me that no single system will be optimal. A multilayerd system
would be much better. Visibility enhancement is good but you have to be
looking in the right direction for it to work. Adding a simple system
like
the transponder receivers or a more elaborate system like FLARM to alert
the
pilot that an intruder is nearby makes the high visibility systems work
better.

Therefore, a couple of disco lights like they have on the top of cop and
ambulance cars, high power lasers coupled into the FLARM (so you know where
they are) to make the offending ignoramus's wings look like swiss cheese
(thereby increaseing visibilty by letting more sunlight through and creating
a lovely shadow effect), all linked into the OLC with a prize winner at the
end of the month. That might get people looking out the window!!

haha (so much bottle left at the end of the red...damn)
Sorry, couldn't resist, even though I should know better....

wrote:

Now having all contestants carry FLARM at a big US regional or better
contest - that could be useful.

It doesn't quite work like that. The only situation where everybody
needs FLARM is if nobody is looking out. Any level of FLARM use greater
than one is useful. Obviously more would be better but quite low levels
of FLARM usage significantly improves your chance of detecting - and
avoiding - an impending collision.

Wanting 100% fitment before it's useful seems to indicate you feel you
could then relax - like a doctor in a Bonanza - but I'm sure you don't
see it that way.

FLARM is directed see and avoid. It's to direct your lookout, not
replace it. Making it mandatory would waste the money of the vigilant
few and encourage the worst habits of the complacent. We have enough
bureaucracy, lets leave it optional. The element of uncertainty will
help keep us all looking.

Graeme Cant


Kirk
66

Hi,

Does it spot individuals or just that one is nearby?

FLARM-equipped aircraft broadcast their position once every second.

Other FLARM-equipped aircraft when in range can track individual
targets and sort them by likelihood of collision. The software takes
into account soaring special cases like thermalling.

If there is a high chance of collision an audible warning is given,
increasing in volume and general air of urgency with decreasing time
to impact. The display gives the direction to the target in a very
clear way.

Hear the beep, check the display, look out to spot. Very easy and
intuitive.

If flying in areas that are covered by the internal database you get
added warnings for hard to see obstacles like cables strung across
valleys.

Ciao, MM
--
Marian Aldenhövel, Rosenhain 23, 53123 Bonn
http://www.marian-aldenhoevel.de
"I sog' Ich, er sogt I. I sog' Ei, er sogt egg. I sog' Eck,
er sogt corner. I sog' koana, er sogt nobody."

Graeme Cant wrote:
FLARM is directed see and avoid. It's to direct your lookout, not
replace it. Making it mandatory would waste the money of the vigilant
few and encourage the worst habits of the complacent. We have enough
bureaucracy, lets leave it optional. The element of uncertainty will
help keep us all looking.

Although seriously perverted in the detail, this is correct in so far as
FLARM is directed see and avoid.

Where this analysis falls off the rails is the assertion that an element
of uncertainty will "help keep us all looking out".

Were that true, then we would have devices fitted to our parachutes that
would randomly disable them so to encourage us to avoid their use after
a collision! I certainly am not aware of any such device, but perhaps
the author of the above remarks can sell you one as he, of course,
always flies with such a device.

Back in the real world, those of us who have now flown many competition
and club hours with FLARMs are convinced of their value by our experience.

I - and indeed every single pilot I have spoken with about using FLARM -
have experienced FLARM pointing out a glider too us before we had
acquired it through our scan.

Of course, it would be possible to claim that this just proves that our
scans were inadequate - which obviously they were as we did not see the
gliders before FLARM pointed out to us. However, this entirely misses
the point that, for competition pilots, we are talking about probably
the most collision and look out aware group of pilots in Australia. If
their scan is missing gliders, what about the average club pilot?

The simple fact of the matter is that no scan is ever going to be
perfect (even allowing for blind spots, which all gliders have). FLARM
augments our scan, it can never replace it.

Even if every glider was fitted with FLARM (and ignoring the possibility
of FLARM failures from whatever cause), we would still need to maintain
an excellent scan: I see no evidence that wedge tailed eagles (or other
large birds) are under any evolutionary pressure to evolve FLARM units
(to name but one of many non-FLARMed airspace users).

FLARM is a great way of augmenting our lookout, as it helps us find
those airspace users that are proven to present the highest collision
risk: other gliders (and glider tugs).

--
Robert Hart
+61 (0)438 385 533 http://www.hart.wattle.id.au