VNAV, LPV, and the future GLS give vertical guidance,
for "Near-Precision Approach" (like ILS) specifications, hence DH.

GPS and LNAV are non-precision, and therefore MDA is appropriate.
They are still based on "Dive and Drive".

Your Garmin 430 computes position updates only once per second,
so it can be certified only under TSO-C129.
Your G-430 GPS approaches are restricted to non-precision.

You would need a TSO-C145 or TSO-C146 unit for precision approaches.
Those units must update their positions five times per second.

I am undergoing a CNX-80/MX-20 installation at this exact moment.
I hope to learn a lot more about this topic in the very near future.
---JRC---

"PA28Rdrvr" wrote in message =
...
Hello. I see there are lots of smart folks in this NG and I learn a =
lot
from you. I have a question that I sure someone can answer for me. =
I'm not
so knowledgeable about some of the GPS approach procedures. I was =
reviewing
the GPS 16L @ KHEF (Manassas VA) and am not sure which DH is =
applicable to
my flying. I am not sure why the difference in LPV DA; LNAV/VNAV DA; =
and,
LNAV MDA. I fly a PA28R with a Garmin 430. Which landing minimum =
would
apply to me? Could someone expound on what each minimum applies to =
and the
decision process for determining which one applies to a particular =
aircraft?
I believe it is usually different types of on board equipment that =
would be
the determining factor but I do not know what is required for each. =
So far,
I have not been able to locate any educational reading that would =
explain it
for me.
Thanks in advance for your helpful comments.
=20