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On Friday, May 25, 2012 9:51:31 AM UTC-5, Darryl Ramm wrote:
On 5/25/12 5:03 AM, Jim wrote:
On Tuesday, May 22, 2012 3:47:40 PM UTC-4, Ramy wrote:
...snip...
It is clear to everyone but you that PF does not currently support TIS-B since there is no point in supporting it now. *If* and when there will be a need to support it, it should be a software upgrade since the hardware supports it.
...snip...

Ramy, I may misunderstand ADS-B but if PF could just tell me a biz jet is about to skewer me from behind I wouldn't say "there is no point" having it in PF *NOW*. I fly near NY class B and having location of commercial jets would be more valuable than knowing where all the gliders are.

-Jim

Jim

Maybe you could describe the avionics you have on board today to address
with your concern here. Do you fly with a transponder? What model? (some
Mode S transponders may give you a path to ADS-B data-out in future). Do
you have ADS-B data-out or have you looked at what is involved in
installing that? Do you have a PowerFLARM installed yet--and how much
1090ES direct traffic are you seeing reported by the PowerFLARM? Is your
glider certified or experimental? Do you talk to ATC where you fly?

This thread has devolved into a rant about TIS-B, it is not talking
about ADS-B per-se it talking about one particular feature, and for that
a PowerFLARM or and other ADS-B data-in device won't receive any TIS-B
data unless your glider has ADS-B data-out equipment installed and
configured correctly.

Wether PowerFLARM decodes TIS-B messages is really an academic question
right now since its virtually impossible to get ADS-B data-out in a
certified glider and it not clear whether simple installs begin done in
some experimental aircraft will continue working in the future as the
FAA tightens technical standards requirements.

But more importantly than any of this, if you are flying near busy
airspace and concerned about commercial jet traffic the one thing to be
thinking of before anything else, including PowerFLARM and/or ADS-B, is
a transponder. The transponder makes you visible to ATC, tells them you
are a glider (if squawking 1202) and most importantly of all make your
glider visible to TCAS II carried by virtually all airliners and many
fast jets, military transports etc. TCAS II is the only system that
issues instructions to pilots on how to avoid a collision, overriding
ATC instructions etc. An airliner or fast jet with TCAS II has the
warning range and energy to avoid whatever you are likely to do in a
glider. A glider pilot may be left with few options, trying to play
"chicken" on an invisible freeway with a fast opponent.

And if the commercial jet you are worried about has 1090ES data-out your
PowerFLARM will see it directly today, with higher precision than TIS-B
and no need for an expensive and complex ADS-B data-out installation. By
2020, and in practice likely earlier, the airlines and many other
aircraft (anybody who flies over FL180) have to equip with 1090ES
data-out. And you will see them all. But again, its much more important
that ATC and TCAS sees you, and also possibly (depending on the exact
situation) that you also in radio communication with ATC.

Darryl

There are two reasons that TIS-B support is not an "academic question".

1. TIS-B will not work without the aircraft outputting an ADS-B Out signal.. There are a lot of aircraft which are already equipped with ADS-B OUT capable hardware. The only thing stopping them from turning this functionality on are some misguided FAA regulations.

The more TIS-B capable equipment there is deployed, the stronger the political presure that we can bring to bear on the FAA to get off the time and relax the ADS-B OUT specs for VFR use. The PowerFLARM guys could be really helpful if they supported this effort. Arguing that TIS-B is a waste of time and is useless, undermines the efforts that AOPA, MITRE, and others are making to try to get the FAA to see the light.

2. For many pilots, both glider and GA power, TIS-B provides the kind of functionality that will get people off the fence to buy equipment now, rather than wait for everyone else to equip. I suspect that if PowerFLARM included TIS-B, and the FAA relaxed the ADS-B OUT specs, not only would many glider pilots buy PowerFLARMS, but they would also buy something like a Trig 21, which would make them visible to jet aircraft TCAS systems; a win/win for everyone.