WAAS for GNS 430/530?

But does this feature work as enhancements to existing SDF/LOC approaches?

I don't think so. We'll have to wait years, if ever, for these LPV
approaches to come to our area.

My $0.02, {|;-)

Victor J. (Jim) Osborne, Jr.

VOsborne2 at charter dot net
"Roy Smith" wrote in message
...
Marco Leon mmleon(at)yahoo.com wrote:
It sucks but realistically, how many airports have LPV approaches without
an
ILS somewhere? Then compare that list to what you will realistically fly;
then pare it down to to chances of requiring the 250ft DH to break out of
the ceiling. I'd think anyone would come up with a very short list of
pilots
this would impact.

One of the cool things about WAAS is the ability to fly a synthetic
glideslope on a non-precision approach. I'd much rather follow a
needle smoothly down to MDA than dive-and-drive through a couple of
stepdowns, even if the MDA is still the same 500 AGL or whatever.

Victor J. Osborne, Jr. wrote:

But does this feature work as enhancements to existing SDF/LOC approaches?

My reading of the advertising-speak is that it can build a descent profile
for any approach. I've some question about that (ie. what if the straight
line from FAF to VDP passes under a stepdown), but I don't know that I've
interpreted the advertising-speak accurately.

- Andrew

"Andrew Gideon" wrote in message =
online.com...
Victor J. Osborne, Jr. wrote:
=20
But does this feature work as enhancements to existing SDF/LOC =
approaches?
=20
My reading of the advertising-speak is that it can build a descent =
profile
for any approach. I've some question about that (ie. what if the =
straight
line from FAF to VDP passes under a stepdown), but I don't know that =
I've
interpreted the advertising-speak accurately.
=20
- Andrew

I agree the "advertising-speak" seems to say what you interpreted.
But I've yet to encounter a computed glide slope for any SDF/LOC
or VOR approaches in my CNX80.
(If some are there, though, someone will surely tell us so.)

However, it seems like all RNAV (GPS) approaches, as well as a majority
of the plain-vanilla GPS approaches do give me vertical guidance,
to which I can couple my 3-axis autopilot if I so choose.
During practice, I make sure I'm comfortable either coupled or =
uncoupled.

Regarding the "straight line from FAF to VDP passing under a stepdown",
that's handled by a charting a delay before descending until reaching a =
point
from which the stabilized descent *will* meet obstruction-clearance =
criteria.
The CNX80/GNS480 follows that charting.
It does not start the descent from the FAF when it's incorrect to do so.

John R. Copeland wrote:

Regarding the "straight line from FAF to VDP passing under a stepdown",
that's handled by a charting a delay before descending until reaching a
point from which the stabilized descent will meet obstruction-clearance
criteria. The CNX80/GNS480 follows that charting.
It does not start the descent from the FAF when it's incorrect to do so.

That's a nice solution; I wish I could see it for myself grin.

- Andrew

Does the computed glideslope indication meet obstacle clearance (i.e.
stepdown altitudes and whatnot) even if the approach is flown a couple
of dots low on the glideslope indication? Or does the pilot/autopilot
need to be absolutely sure that the approach is flown smack in the
middle or a couple dots high?

-Jon C.


"John R. Copeland" wrote in message
.. .

....

Regarding the "straight line from FAF to VDP passing under a
stepdown",
that's handled by a charting a delay before descending until reaching
a point
from which the stabilized descent *will* meet obstruction-clearance
criteria.
The CNX80/GNS480 follows that charting.
It does not start the descent from the FAF when it's incorrect to do
so.

"Jon Carlson" wrote:

Does the computed glideslope indication meet obstacle clearance (i.e.
stepdown altitudes and whatnot) even if the approach is flown a couple
of dots low on the glideslope indication? Or does the pilot/autopilot
need to be absolutely sure that the approach is flown smack in the
middle or a couple dots high?

I think that's kind of like asking, "Does the MDA meet obstacle clearance
even if you go below it?".

I think the answer to both questions is the same, "There's some
TERPs-defined buffer built in, but from the pilot's point of view, all you
gotta know is don't go below what the procedure says until you can see the
runway".

I think that's kind of like asking, "Does the MDA meet obstacle
clearance
even if you go below it?".

Sort of, but one of the advantages of WAAS generated glideslopes is
that it enables autopilot coupled approaches with vertical guidance.
So... if a dot or two off runs you through a hill, that might be a
nice thing to know and correlate with your autopilot's level of
precision...


I think the answer to both questions is the same, "There's some
TERPs-defined buffer built in, but from the pilot's point of view,
all you
gotta know is don't go below what the procedure says until you can
see the
runway".

Yes, we are still responsible for not descending below the MDA. But we
need to understand the limitations of the box if we're going to let
the box help us so that we can know what we have to do to live up to
those responsibilities.

-Jon C.