Anyone flown atn LPV yet?

John R. Copeland wrote:

"Sam Spade" wrote in message ...

John R. Copeland wrote:


"Sam Spade" wrote in message ...


With LPV, the sensitivity continues to increase (course width decreases)

from the FAF to the runway. That causes LPV to be an angular system
from the FAF to the runway. Not so with other RNAV.


Thanks. I didn't know of the difference. I'll watch for it.


I getting up to speed on the 145/146 spec. The LNAV approach also
reduces in the lateral mode similar to the laternal mode of the LPV
approach. When you reach the MAP, it is only 350 feet full scale
deflection, instead of the 0.3 mile defection for TSO 129 LNAV final.


I'm definitely gonna have to set up an experiment over that!
I'd expect to have noticed it, if my CNX80 behaved that way.
Is that a behavior demanded by TSO-C145/146, or merely allowed?


Stay tuned.

John R. Copeland wrote:
"Sam Spade" wrote in message ...

John R. Copeland wrote:


"Sam Spade" wrote in message ...


With LPV, the sensitivity continues to increase (course width decreases)

from the FAF to the runway. That causes LPV to be an angular system
from the FAF to the runway. Not so with other RNAV.


Thanks. I didn't know of the difference. I'll watch for it.


I getting up to speed on the 145/146 spec. The LNAV approach also
reduces in the lateral mode similar to the laternal mode of the LPV
approach. When you reach the MAP, it is only 350 feet full scale
deflection, instead of the 0.3 mile defection for TSO 129 LNAV final.


I'm definitely gonna have to set up an experiment over that!
I'd expect to have noticed it, if my CNX80 behaved that way.
Is that a behavior demanded by TSO-C145/146, or merely allowed?


The following language suggests that LNAV must always be 350 feet at the
MAP. Both Figures 2-12 and 2-13 show 350 at the MAP.

2.2.3.3.1 Approach Path Definition

If the pilot has not selected a VTF approach, deviations shall be
provided with respect to the active leg of the approach procedure. See
Figure 2-12. If the pilot has selected a VTF approach, deviations shall
be provided relative to the inbound course to the FAF. See Figure 2-13.
The active waypoint shall initially be the FAWP. The equipment should
also account for short turns onto the final approach where the FAWP may
not be crossed.

Note 1: A VTF approach can be selected at any time.

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)

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



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)

I am playing with the new Garmin 400/500W trainer and the needle
movement is very smooth.

I also verified the great difference between when the scaling becomes
localizer-like with VTF and own-nav.

I flew the LPV into KIXD Runway 36. Using VTF, I did an intercept 8
miles prior to JIKLA (the FAF). The CDI scaling was already well below
1 mile. Then I did an intercept at the same position with ANQUIM (the
IF) to JIKLA as the active leg. The needle came off the peg at 1 mile
crosstrack error.

The 530W also has a nice feature, not present in th 530. When there is
a course change at a waypoint it shows a broken magenta line, which is
the flyby course that will be flown if on autopilot. Positive course
gudiance in holds and procedure turns using highly accurate
roll-steering is great, too. (For FD or autopilot, those too need to
have roll steering to get the most out of these curved flight paths.)

On Fri, 22 Dec 2006 09:10:02 -0800, Sam Spade wrote:

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



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)

I am playing with the new Garmin 400/500W trainer and the needle
movement is very smooth.

I also verified the great difference between when the scaling becomes
localizer-like with VTF and own-nav.

I flew the LPV into KIXD Runway 36. Using VTF, I did an intercept 8
miles prior to JIKLA (the FAF). The CDI scaling was already well below
1 mile. Then I did an intercept at the same position with ANQUIM (the
IF) to JIKLA as the active leg. The needle came off the peg at 1 mile
crosstrack error.

The 530W also has a nice feature, not present in th 530. When there is
a course change at a waypoint it shows a broken magenta line, which is
the flyby course that will be flown if on autopilot. Positive course
gudiance in holds and procedure turns using highly accurate
roll-steering is great, too. (For FD or autopilot, those too need to
have roll steering to get the most out of these curved flight paths.)

I have no experience with anything other than the 480, so can't comment. I
also do not have a roll-steering a/p.

The 480 does show a solid curved magenta line for course changes at
waypoints representing the expected flight path.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

"Sam Spade" wrote in message
...
The 530W also has a nice feature, not present in th 530. ......snip...
Positive course gudiance in holds and procedure turns using highly
accurate roll-steering is great, too. (For FD or autopilot, those too
need to have roll steering to get the most out of these curved flight
paths.)

According to the GNS430W manual, the unit does not provide positive course
guidance in holds except on the inbound leg, which is not a change from the
430, and does not provide positive course guidance on a PT except on the
outbound and inbound portions (not during the reversal itself), which is
also not a change from the 430.

Regarding roll steering, it says "For roll steering autopilots: roll
steering is terminated when approach mode is selected on the autopilot and
is available once the missed approach is initiated." I don't really
understand this statement.

I didn't read the 530W manual. Is it different?

Stan Prevost wrote:
"Sam Spade" wrote in message
...

The 530W also has a nice feature, not present in th 530. ......snip...
Positive course gudiance in holds and procedure turns using highly
accurate roll-steering is great, too. (For FD or autopilot, those too
need to have roll steering to get the most out of these curved flight
paths.)


According to the GNS430W manual, the unit does not provide positive course
guidance in holds except on the inbound leg, which is not a change from the
430, and does not provide positive course guidance on a PT except on the
outbound and inbound portions (not during the reversal itself), which is
also not a change from the 430.

Regarding roll steering, it says "For roll steering autopilots: roll
steering is terminated when approach mode is selected on the autopilot and
is available once the missed approach is initiated." I don't really
understand this statement.

I didn't read the 530W manual. Is it different?



It says the same thing.

I don't understand the limitation, either. It will have to be changed
if they want to take advantage of RF legs, which will eventually appear
in some Basic RNP IAPS, when the criteria are changed. High end birds
that have roll steering do not have such a limitation.

As to the PCG, in spite of what the manual says, it works in the
trainer. The trainer historically has been accurate.

Sam Spade wrote:
Dave Butler wrote:

Yes, LPV IAP. Jeppesen is so full of it. Those LPV approaches are for
any database in a TSO 145/146 set, which means the GNS480.

I haven't given any instruction in the 480's since the TSO. I'm waiting
for the G1000 to get approved.
-Robert

Robert M. Gary wrote:
Sam Spade wrote:
Dave Butler wrote:

Yes, LPV IAP. Jeppesen is so full of it. Those LPV approaches are for
any database in a TSO 145/146 set, which means the GNS480.

I haven't given any instruction in the 480's since the TSO. I'm waiting
for the G1000 to get approved.
-Robert

Just for the record, despite the words "Dave Butler wrote:", nothing in
this article contains any of my words.

Dave Butler

Dave Butler wrote:

Robert M. Gary wrote:

Sam Spade wrote:

Dave Butler wrote:

Yes, LPV IAP. Jeppesen is so full of it. Those LPV approaches are for
any database in a TSO 145/146 set, which means the GNS480.


I haven't given any instruction in the 480's since the TSO. I'm waiting
for the G1000 to get approved.
-Robert


Just for the record, despite the words "Dave Butler wrote:", nothing in
this article contains any of my words.

Dave Butler


Those were my words.