WAAS for GNS 430/530?

In article ,
Matt Barrow wrote:

"Andrew Gideon" wrote in message
gonline.com...
Matt Barrow wrote:

Think about breaking out at the MAP...you've got 0.2 seconds to make
your
decision.

Perhaps I'm misinterpreting what you've written, but how is this different
than a 'real' precision approach?


When you reach the MAP after D&D, you're stable in three axes. How would you
rather be when looking for the runway?

When you reach the MAP after following a glide slope, you should also
be stable in three axes (heading, pitch, and bank should all be
constant). Even better, if you see the runway, you can continue to
hold that attitude down to the surface.

If anything, the slight nose-down pitch attitude should make it easier
to see the runway, compared to having to search for it over the nose
in level flight after a dive-and-drive.

Andrew Gideon wrote:
Matt Barrow wrote:


Think about breaking out at the MAP...you've got 0.2 seconds to make your
decision.


Perhaps I'm misinterpreting what you've written, but how is this different
than a 'real' precision approach?

- Andrew


I believe he is saying that dive and drive gets you broken out sooner, since
you are down at the minimum altitude considerably befor the map.

Scott Moore wrote:

Think about breaking out at the MAP...you've got 0.2 seconds to make your
decision.


Perhaps I'm misinterpreting what you've written, but how is this
different than a 'real' precision approach?

I believe he is saying that dive and drive gets you broken out sooner,
since you are down at the minimum altitude considerably befor the map.

Perhaps, but that's still the same as a precision approach. If reaching the
MDA at the same moment that one much decide whether or not to continue the
approach (ie the VDP) is a Bad Thing, why isn't it bad on a precision
approach?

- Andrew

"Scott Moore" wrote in message
...
Andrew Gideon wrote:
Matt Barrow wrote:


Think about breaking out at the MAP...you've got 0.2 seconds to make
your
decision.


Perhaps I'm misinterpreting what you've written, but how is this
different
than a 'real' precision approach?

- Andrew


I believe he is saying that dive and drive gets you broken out sooner,
since
you are down at the minimum altitude considerably befor the map.

You've got it.

Did you read Deakins article? He's a much better writer/spokesman than I.

Doug wrote:

A pilot can use either technique. Depending on the pilot, the aircraft,
and the approach, there are positives and negatives to using dive and
drive vs. stabilized constant descent technique.

The accidents stats don't support any positives for dive-and-drive.



One thing you frequently hear is that you could IMMEDIATELY descend
(helicopter) to the next altitude once you pass the waypoint. NOT true.
There is a maximum decent allowed. I don't know what it is, and it is
quite steep, but it's not vertical.

What is the number? Why express any uncertainty? With one exception you
have full obstacle clearance at the earlist point at which a fix can be
received (i.e., considering adverse fix error).

The exception is in the non-precision final approach segment where a 7:1
gradient may, or may not, be applied to the FAF and/or some stepdown fix in
the final approach segment. A pilot has no way of determing from the
approach chart whether this design option has been applied (TERPs,
Paragraph 289).

wrote in message ...


Doug wrote:

A pilot can use either technique. Depending on the pilot, the aircraft,
and the approach, there are positives and negatives to using dive and
drive vs. stabilized constant descent technique.

The accidents stats don't support any positives for dive-and-drive.

Cite?

Matt Barrow wrote:

wrote in message ...


Doug wrote:

A pilot can use either technique. Depending on the pilot, the aircraft,
and the approach, there are positives and negatives to using dive and
drive vs. stabilized constant descent technique.

The accidents stats don't support any positives for dive-and-drive.

Cite?

How can I cite the negative? There are many, many NPA crashes over the years.

wrote in message ...


Matt Barrow wrote:

wrote in message
...


Doug wrote:

A pilot can use either technique. Depending on the pilot, the
aircraft,
and the approach, there are positives and negatives to using dive
and
drive vs. stabilized constant descent technique.

The accidents stats don't support any positives for dive-and-drive.

Cite?

How can I cite the negative?

The same way you assert it.

There are many, many NPA crashes over the years.

And how many were attributable to D&D, rather than stabilized descent?

"Paul Lynch" wrote in message
news:K9spe.10456$%Z2.3221@lakeread08...
Stable approaches for the heavy metal???? Stable approaches work for all
aircraft on non-precision approaches.

Wanna re-read my original post.

Indeed they do, but the intent was the turbine traffic, not 172's.

Maybe someone explained them to you
poorly or incorrectly. Stable means a constant descent rate that puts you
at MDA shortly before the MAP.

I know what they mean.

Dive and drive is frowned on by the FAA
because of the multiple accidents nor near mishaps or altitude busts that
occur.

Do you have a cite for that?

INHMB


"Matt Barrow" wrote in message
...

"Roy Smith" wrote in message
...
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.

Problem with a smooth descent is that when you arrive at the sectors
MDA,
you have immediately start down again rather than taking a few moments
to
sift things out. Stable approaches were build for the heavy
metal/turbine
crowd.

http://www.avweb.com/news/columns/182091-1.html
Pelican's Perch #24:
Sloppy, Sorry VNAV

Flying a non-precision approach has traditionally been a "Dive and
Drive"
affair in which the pilot descends rapidly to the MDA or step-down
altitude
and then levels off. Recently, however, pilots of aircraft equipped with
glass cockpit FMS systems or VNAV-capable GPS receivers have been
encouraged
to fly such approaches using a constant descent path. There's even a
buzzword for this: CANPA (constant-angle non-precision approach), and
these
calculated pseudo-glideslopes are now starting to show up on Jeppesen
approach plates. AVweb's John Deakin thinks this is a bad idea, one that
will result in a lot more missed approaches and perhaps even some
accidents.
Deakin explains why, and makes a compelling case for flying
non-precision
approaches the traditional, old-fashioned way that God and Cap'n Jepp
intended.

----------------------------------------------

Matt Barrow wrote:

"Paul Lynch" wrote in message
news:K9spe.10456$%Z2.3221@lakeread08...
Stable approaches for the heavy metal???? Stable approaches work for all
aircraft on non-precision approaches.

Wanna re-read my original post.

Indeed they do, but the intent was the turbine traffic, not 172's.

The intent was certainly directed to turbine airplanes, but the concept was
recommended for all airplane operations.

As to Deakin's views on the matter, other folks with similar expertise disagree
quite strongly with him. He is a smart fellow, but when it comes to
dive-and-drive, it's simply his opinion, which is no better than anyone else's
that works with that stuff. In fact, Deakin never participated in any
Industry/FAA meetings or discussions about constant angle/constant rate NPAs.