"Richard Kaplan" wrote in message
news:0649e5cf70eaff69b32e0896c22e491f@TeraNews...
There was an intresting talk at Oshkosh about the WAAS system by one of
the
members of the UPSAT engineering team.

As an aside, he defensively mentioned that the CNX-80 would be certified
for
precision approaches in "fourth quarter 2003." The sales rep on the floor
were more confident that certification would occur in October 2003. Who
knows what exactly to believe.

Perhaps more interestingly, he showed approach plates for
under-development
WAAS LPV approaches to Gaithersburg, MD and Red Wing, MN with minimums of
250 - 3/4. Those approch plates had separate minimums listed for LPV,
VNAV/LNAV, LNAV, and circling approaches. He indicated that currently the
CNX-80 can only fly an approach down to LNAV minimums but ultimately it
will
meet LPV minimums. However, when flying the LPV approach if the WAAS
system
should be flagged as inoperative then the pilot could instead fly to
VNAV/LNAV minimums.

He indicated that current-generation non-WAAS receivers are not approved
to
fly the precision VNAV/LNAV approaches yet the WAAS-approved CNX-80 will
be
approved to fly VNAV/LNAV approaches with WAAS inoperative.

The AIM is somewhat ambiguous on this topic, implying that VNAV/LNAV is
separate from the WAAS system but requires accuracy equivalent to
barometric
altimetry.

I am not sure what to make of this, and I suspect there will be an
important
learning curve when these approaches and these GPS receivers become more
common.

Any further thoughts?

This way you get something for all those WAAS development dollars.