Anyone flown atn LPV yet?

Ron Rosenfeld wrote:
On Fri, 15 Dec 2006 06:56:17 -0800, Sam Spade wrote:

Subject line says it all.

If so, what was your impression?

Not yet. But I have flown an LNAV with advisory vertical guidance. The
needles were extremely stable -- more so than an ILS with my equipment.
Pretty easy to fly.


Ditto...I even coupled the autopilot... real nice.

"Ron Rosenfeld" wrote in message ...
On Fri, 15 Dec 2006 06:56:17 -0800, Sam Spade wrote:

Subject line says it all.

If so, what was your impression?

Not yet. But I have flown an LNAV with advisory vertical guidance. The
needles were extremely stable -- more so than an ILS with my equipment.
Pretty easy to fly.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

Yes, the approaches are a pleasure to fly, but the step change in course
width can cause a coupled approach to give a small disturbance, for me.
If the needle isn't exactly centered at the point of switching,
my autopilot hunts for a few moments, until it stabilizes again.
It's a small amount, and not an operational problem, but it makes the GPS
approaches slightly less smooth than an ILS, which doesn't have that bump.
My autopilot is a Collins AP-107.
Who sees any similar effect with other autopilots?

John R. Copeland wrote:
"Ron Rosenfeld" wrote in message ...
)


Yes, the approaches are a pleasure to fly, but the step change in course
width can cause a coupled approach to give a small disturbance, for me.
If the needle isn't exactly centered at the point of switching,
my autopilot hunts for a few moments, until it stabilizes again.
It's a small amount, and not an operational problem, but it makes the GPS
approaches slightly less smooth than an ILS, which doesn't have that bump.
My autopilot is a Collins AP-107.
Who sees any similar effect with other autopilots?


Is this a GNS 480 that is giving the step changes? Do you see these
small incremental changes on your CDI or HSI?

On Sat, 16 Dec 2006 11:52:57 -0500, "John R. Copeland"
wrote:

"Ron Rosenfeld" wrote in message ...
On Fri, 15 Dec 2006 06:56:17 -0800, Sam Spade wrote:

Subject line says it all.

If so, what was your impression?

Not yet. But I have flown an LNAV with advisory vertical guidance. The
needles were extremely stable -- more so than an ILS with my equipment.
Pretty easy to fly.


Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

Yes, the approaches are a pleasure to fly, but the step change in course
width can cause a coupled approach to give a small disturbance, for me.
If the needle isn't exactly centered at the point of switching,
my autopilot hunts for a few moments, until it stabilizes again.
It's a small amount, and not an operational problem, but it makes the GPS
approaches slightly less smooth than an ILS, which doesn't have that bump.
My autopilot is a Collins AP-107.
Who sees any similar effect with other autopilots?

I've not noted a "step change" in my CNX80. The changes in sensitivity are
supposed to be gradual, and at the FAF I believe the "scaling" goes to
angular, to mimic an ILS. But maybe I've just missed it.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

Ron Rosenfeld wrote:




I've not noted a "step change" in my CNX80. The changes in sensitivity are
supposed to be gradual, and at the FAF I believe the "scaling" goes to
angular, to mimic an ILS. But maybe I've just missed it.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

As I understand it, it first ramps down to 0.3 from 1.0 starting at 2
miles from the LPV FAF, then it does a continuous angular "ramp down"
from the FAF to the runway so it will be ILS-like close in. Have you
noted that doing small incremental "stepping" on an LPV IAP during final
approach?

"Sam Spade" wrote in message ...
Ron Rosenfeld wrote:




I've not noted a "step change" in my CNX80. The changes in sensitivity are
supposed to be gradual, and at the FAF I believe the "scaling" goes to
angular, to mimic an ILS. But maybe I've just missed it.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

As I understand it, it first ramps down to 0.3 from 1.0 starting at 2
miles from the LPV FAF, then it does a continuous angular "ramp down"
from the FAF to the runway so it will be ILS-like close in. Have you
noted that doing small incremental "stepping" on an LPV IAP during final
approach?

You say LPV course widths ramp down gradually over some miles?
Should LNAV/VNAV approaches do the same?
Around the FAF, it's usually too busy a time to collect every detail.
If it's not a step change in course width, it seems at least pretty quick.
Quick enough to disturb my autopilot a small amount, it seems.
But the reason I asked was to learn if other CNX80 users see a similar effect.
So far, the answer seems to be "no".
The effect I see is small, though, so it could be ignored easily.

If the blame turns out to be on my autopilot, I could send it back
to Collins to get it re-calibrated.

On Sun, 17 Dec 2006 06:59:39 -0800, Sam Spade wrote:

Ron Rosenfeld wrote:




I've not noted a "step change" in my CNX80. The changes in sensitivity are
supposed to be gradual, and at the FAF I believe the "scaling" goes to
angular, to mimic an ILS. But maybe I've just missed it.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

As I understand it, it first ramps down to 0.3 from 1.0 starting at 2
miles from the LPV FAF, then it does a continuous angular "ramp down"
from the FAF to the runway so it will be ILS-like close in. Have you
noted that doing small incremental "stepping" on an LPV IAP during final
approach?

Well, I'm hand-flying most of the approaches, and the CDI is generally
centered prior to the FAF, so I wouldn't note a sudden change in
sensitivity on the final segment.

I do, of course, note the change going from enroute to terminal mode, and
from terminal to approach mode if I have any CDI deflection.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)