Of course you all know that I'm not a Flarm guy.

Having said that, it strikes me funny that nobody seems to have noticed that
it's the "same altitude" aircraft that's going to hit you. Why would you
want all transponders at co-altitude to be suppressed? And the notion that
you're going to be OK since the Flarm will point out other Flarm traffic.
Listen up, Guys: GA, military, and airlines are NOT using Flarm. Oh, and
we have at least one guy at Moriarty who has a Flarm but not a transponder.
So he and the half dozen or so Flarm equipped gliders can avoid each other
but he's cruising along blissfully unaware that ATC can't see him, nor can
the airliners or military flights that buzz in and out of ABQ daily.

Hopefully Flarm will work this out as Zaon did several years ago.


"darrylr" wrote in message
...
On Saturday, April 19, 2014 2:49:22 PM UTC-7, wrote:
It would be nice to have the option to include a list of transponder codes
that were always suppressed. For example, 1202. One could make the
determination if a majority of the local gliders with a transponder also
had FLARM. If that was a reasonable assessment for your location, then
suppressing all the 1202 hits would potentially reduce the false alarms
based on transponders and would rely on the more reliable FLARM data.

Ah the trouble there is you cannot definitively associate a Mode A squawk
reply with the same transponder doing a Mode C reply. And there will be
situations where targets are doing Mode C only replies (e.g. any time a
target is being interrogated by TCAS I or II but out of range of ground
SSR... which I'm guessing happens a fair amount).

The 'best' you could do in that situation is stop all PCAS warnings. That
may be/is likely too drastic, you can also so try adjusting the PCAS
height/range parameters. Ultimately there is nothing you can do that is
goign to work that well with Mode C transponders. Hopefully over time this
will go away as an issue as Mode S transponder use keeps growing in the USA
glider fleet.

There is no need/strong justification to replace a Mode C today, they work
great for letting ATC know where you are and with TCAS, TCAD and PCAS in GA
aircraft etc. but on the other hand there is no sane reason to buy a new
Mode C transponder today. The possible issues here with PowerFLARM
interoperability is just one of those reasons. Over time and as equipment
ages and gets expensive to repair and new Mode S transponder technology
hopefully keeps falling in cost and size etc. we'll just see the current
Mode C usage in the glider fleet migrating over to Mode S. I'm much less
worried about Mode C vs. Mode S than I am to encourage *any* transponder use
in areas of high airline, fast jet, and even GA traffic.

Anybody who what my opinion on what the FAA should have really done with
Mode S vs. Mode C transponders and ADS-B Out carriage mandates, etc. is
welcome to buy me a six pack of beer and put up with an hour of whining.