On Tuesday, June 16, 2015 at 1:32:53 PM UTC-5, jfitch wrote:

If the proposed rule making and TS0-C199 equipment could be so aligned that existing ADB compliant installations (in gliders there are only 2 or 3 brands), preferably with cheap or existing GPS receivers can be made to work (and I can see no reason why it would be technically difficult) then for many private gliders the cost would be low. For gliders with no current Mode S transponder, the costs would be approximately what a transponder install costs today ($3K maybe?).

I think you mixed a couple of terms. If you have an ADS-B compliant installation, you don't need the cheap/existing GPS source. If you have Mode S, then if the regs align and you can get a cheap/existing GPS approved, then the cost would be low.

But, this is "supposed" to be an option for a system that is to be much lower cost than a transponder. Not as something to put with you existing transponder. Think "handheld radio price-point". The exemption exists primarily because the cost was too great. The lack of an electrical system was chosen as a dividing line.

In the mean time, we wait as Darryl Ramm reads TSO-C199 to see how the government has once again written a spec to assure high prices...

Steve Leonard