It would appear that AOPA is revising it's stance on the mandatory
ADS-B issue, but given the fact that AOPA feels it would only cost
each aircraft owner "thousands of dollars," not tens of thousands of
dollars, it is doubtful they yet fully appreciate the ramifications of
the issue. While mandatory ADS-B equipment might be a step forward
for GA pilot operations, it would seem to me, that it is FAA (and
avionics manufacturers) who stand to receive the most benefit from
this proposal.

Excellent point. The NPRM also only covers ADS-B Out which does not
get the GA pilot free weather or traffic info. I will have to correct
AOPA on that but since it took forever to correct them on the fuel
increase percentage during the user fee debate...it may be hard.

And if mandatory ADS-B installation were to result in the
decommissioning of ATC radar installations, that would be a step
backward, because there would be no backup system in the event of an
outage in ADS-B operation. But more importantly, the validity of
aircraft positional information, upon which ATC currently relies,
would switch from an empirical to reported. That coupled with the
change from terrestrial based communications to satellite based
communications would seem to provide reduced system integrity, IMO.

Concur. The backup strategy is to use SSR with transponders. I am
still unclear if all aircarft must keep curremt Mode C/S transponers
if they get ADS-B Out or if ADS-B Out units incorporate Mode C/S
functionality.

This NPRM is really flawed, makes unsupported conclusions and should
really be withdrawn entirely while they go back to the drawing board
and get some people with common sense helping them.

Ron Lee