Terrence,

Ah - once again, my less-than-adequate explanation has caused confusion.  To
clarify:

In order to legally fly IFR GPS approaches, your equipment needs to meet
TSO-C129a Class A1 for non-precision approaches, or TSO C-146a Class 3 for
use as primary navigation on LPV approaches (which are only available if you
have WAAS).  C129a references RAIM directly, and C146a references several
other documents, and I'm betting one of them has a RAIM reference.  The last
time I checked (which admittedly was several months ago), no handheld GPS or
tablet/laptop/smart phone/PDA based GPS and software combination was
certified to either C129a or 146a, and the only GPS receivers that were
certified to these standards were panel-mount receivers, among them the ones
that I mentioned.  C129a has a bunch of stuff about integrity alarms,
notifications, and annunciations, and C146a has a section on software
qualification, so I'm guessing that situation hasn't changed.

As I understand it (and I could be wrong here), RAIM applies to both WAAS
and non-WAAS approaches.  If a combination of satellite geometry and
satellite/ground station outages can't guarantee a certain accuracy, a WAAS
LPV approach will get downgraded to an LNAV (reduced-precision) approach.

You now know everything I know about TSOs, GPS receivers, and IFR
approaches. Hopefully this clarifies my previous reply.  If not, we may need
Brent to bring his sock puppets and educate both of us.

I was at Branson also, and I was hoping the GAMI talk would have covered
more engine operation, but I must say I learned more about combining benzene
rings and carbon atoms to make either solvent or gasoline than any time
since high-school chemistry, and was informative as to the economics of a
100LL replacement. May give me a project to work on when I finally finish
this plane.

That restaurant at Smartt Field changes ownership on pretty much a yearly
basis, which is a shame since they usually had some decent food.  Since the
local EAA chapter moved their meetings from Sunday afternoon to Saturday
morning, my attendance has, uh, sorta fallen off, so I don't get to the
restaurant as much as I have in the past, but I can't remember that
restaurant going more that 3 years under the same ownership.


Gary Fitzgerald
LNC2 ~70%
St. Charles, MO
Looking for a good deal on a rebuildable (I)O-360