On Friday, July 4, 2014 7:51:13 AM UTC-7, son_of_flubber wrote:
On Friday, July 4, 2014 2:53:41 AM UTC-4, Darryl Ramm wrote:

The situation for experiential aircraft, including gliders, is a bit different. You should be able to do an install with a non TSO-compliant GPS source.



It may be legal to install a non-TSO GPS source in 'experimental' but would there be ANY benefit? From what I read in the link provided by Darryl, the output of un-certified transmitters is ignored.



Darryl wrote:



BTW I just noticed the FAA promoting this ADS-B install information on Facebook. Worth a read for folks interested. http://www.aea.net/ads-b/pdf/FAA_ADSB_06172014.pdf



Excerpt from this FAQ:



Air traffic control does not use data from these

uncertified transmitters, which prevents controllers

from providing flight following services or

separation services to aircraft that are so equipped.

Data from uncertified transmitters are not displayed

on certified ADS-B In displays, and pilots in aircraft

with certified ADS-B equipment will not be able to

see aircraft equipped with uncertified transmitters.

A useful stern warning, but non-approved 1090ES output will likely be visible on lots of displays via ADS-B direct, including on PowerFLARM. So still possibly of some benefit for folks with experiential gliders who are careful and who work with manufacturers to play with non-certified ADS-B out, say for for the increased PowerFLARM detection range that ADS-B out can provide. But that still is in the "geek who wants to play" category, not stuff most pilots should want to mess with. And understanding what enabling non-complaint/uncertified ADS-B out is goign to provide is important.

The FAA's bias here is clearly to encourage compliant ADS-B output, and that is understandable from their NextGen NAS viewpoint (and an overall good thing). ADS-B is unfortunately the proverbial kitchen sink, if you were just designing a GA market collision avoidance system you would do it a lot different than the complex dual-link ADS-B mess the FAA inflicted on pilots in the USA.

I just cannot emphasize enough that the huge benefit or Mode S or C transponders for gliders in in busy airspace, especially around airliners and fast jets. Transponders provide visibility to existing SSR/ATC and TCAS (and TCAD and PCAS) systems. Modern Mode S transponders (like the Trig TT series) are also capable of supporting ADS-B 1090ES Out, that is something that may be nice to have for the future, not something to stress about today. You just don't need that ADS-B complexity to get all the transponder/SSR/TCAS etc. collision avoidance goodness from a transponder today.