Anyone flown atn LPV yet?

[Sam Spade]

Subject line says it all.

If so, what was your impression?

[Robert M. Gary]

Sam Spade wrote:
> Subject line says it all.
>
> If so, what was your impression?

I'm still working on getting my wife to allow me to buy the Eclipse.
I'm wondering if the plane will be treated more like a Citation or a GA
plane. In otherwords, if some high end FBOs will rent them. There are
certainly a lot of skeptics who say "humbug" to anything, but with
proper training (Flight Safety perhaps) maybe I could see an FBO being
able to provide that. With the amount of traveling I do (maybe one 500+
file trip every 2 months) rental would probably make more sense.

-Robert

[Dave Butler]

Robert M. Gary wrote:
> Sam Spade wrote:
>> Subject line says it all.
>>
>> If so, what was your impression?
>
> I'm still working on getting my wife to allow me to buy the Eclipse.
> I'm wondering if the plane will be treated more like a Citation or a GA
> plane. In otherwords, if some high end FBOs will rent them. There are
> certainly a lot of skeptics who say "humbug" to anything, but with
> proper training (Flight Safety perhaps) maybe I could see an FBO being
> able to provide that. With the amount of traveling I do (maybe one 500+
> file trip every 2 months) rental would probably make more sense.

Were you thinking an LPV is an aircraft type? I think Sam meant the
approach type Localizer Precision with Vertical Guidance.

I have a GNS480 but haven't yet flown an LPV approach. There's one shown
in the NACO charts at nearby LHZ, but it's not in the Jeppesen database
(yes, I have version 2.1 of the software). Jeppesen and NACO are
apparently in a ****ing contest about whether the approach is real.
Jeppesen says the LPV approach at LHZ is restricted to authorized users,
NACO says anybody can use it.

DB

[Robert M. Gary]

Dave Butler wrote:
> Robert M. Gary wrote:
> > Sam Spade wrote:
> >> Subject line says it all.
> >>
> >> If so, what was your impression?
> >
> > I'm still working on getting my wife to allow me to buy the Eclipse.
> > I'm wondering if the plane will be treated more like a Citation or a GA
> > plane. In otherwords, if some high end FBOs will rent them. There are
> > certainly a lot of skeptics who say "humbug" to anything, but with
> > proper training (Flight Safety perhaps) maybe I could see an FBO being
> > able to provide that. With the amount of traveling I do (maybe one 500+
> > file trip every 2 months) rental would probably make more sense.
>
> Were you thinking an LPV is an aircraft type? I think Sam meant the
> approach type Localizer Precision with Vertical Guidance.

For some reason I read it as VLJ

-Robert

[Sam Spade]

Dave Butler wrote:

>
> Were you thinking an LPV is an aircraft type? I think Sam meant the
> approach type Localizer Precision with Vertical Guidance.
>
> I have a GNS480 but haven't yet flown an LPV approach. There's one shown
> in the NACO charts at nearby LHZ, but it's not in the Jeppesen database
> (yes, I have version 2.1 of the software). Jeppesen and NACO are
> apparently in a ****ing contest about whether the approach is real.
> Jeppesen says the LPV approach at LHZ is restricted to authorized users,
> NACO says anybody can use it.
>
> DB

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.

[Mike Adams[_2_]]

Sam Spade > wrote:

> Subject line says it all.
>
> If so, what was your impression?

I've flown several of them, but only in practice. The one at KPRC overlays the ILS, but the one at KDVT
(RNAV 25L) gives nice capability to this airport, although the weather hardly ever requires it. It's also a
nice approach for practice, with a 9 mile final approach segment, it gives you lots of time on the needles.
The 480 flies them very nicely. It may be just me, but it seems the deviations are more stable than an
ILS, i.e. no beam bending, side lobes, etc.

Mike

[Sam Spade]

Mike Adams wrote:
> Sam Spade > wrote:
>
>
>>Subject line says it all.
>>
>>If so, what was your impression?
>
>
> I've flown several of them, but only in practice. The one at KPRC overlays the ILS, but the one at KDVT
> (RNAV 25L) gives nice capability to this airport, although the weather hardly ever requires it. It's also a
> nice approach for practice, with a 9 mile final approach segment, it gives you lots of time on the needles.
> The 480 flies them very nicely. It may be just me, but it seems the deviations are more stable than an
> ILS, i.e. no beam bending, side lobes, etc.
>
> Mike
The needles are super stable, much better than most ILSes. They do get
more sensitive as you approach the runway, just like ILS. That had to
be built into the box, because GPS is a linear system. It was necessary
to do that to get the flight technical error to ILS-like values
close-in. It's really a very good system, except for the availability
problems at some locations. ILS doesn't have that problem. ;-)

[Ron Rosenfeld]

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)

[Ron Natalie]

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.

[John R. Copeland]

"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?

[Sam Spade]

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?

[Ron Rosenfeld]

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)

[Sam Spade]

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?

[John R. Copeland]

"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.

[Sam Spade]

John R. Copeland wrote:


> You say LPV course widths ramp down gradually over some miles?
> Should LNAV/VNAV approaches do the same?

RNAV IAPs, other than LPV, ramp down from 1.0 miles to 0.3 miles
starting two miles prior to the FAF, and completed at the FAF. Then,
the sensitivity remains at 0.3 throughout the final approach segment.

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.

[John R. Copeland]

"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.

[Sam Spade]

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.

[Stan Prevost]

"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.

Do you have a link to the TSO handy? And is it the full requirement? Last
time I tried to read TSO C129, seems like it was a skeleton document,
referencing a commercial spec that had to be purchased.

[John R. Copeland]

"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?

[Sam Spade]

Stan Prevost 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.
>
>
> Do you have a link to the TSO handy? And is it the full requirement? Last
> time I tried to read TSO C129, seems like it was a skeleton document,
> referencing a commercial spec that had to be purchased.
>
>
>
Same with 145/146. The nuts-and-boths is in RTCA Doument 229C. $350.

[Sam Spade]

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.

[Sam Spade]

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.

[Ron Rosenfeld]

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)

[Sam Spade]

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.)

[Ron Rosenfeld]

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)

[Stan Prevost]

"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?

[Sam Spade]

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.

[Robert M. Gary]

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

[Dave Butler]

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

[Sam Spade]

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.

[Sam Spade]

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?
>
>
>
I got the straight scoop from a Garmin soothsayer. First, with a Garmin
autopilot there would not be such a limitation. But, this manual is
written on the presumption the aircraft has Brand K or Brand S
autopilots that do have roll steering. But, those brands have to switch
to CDI steering to fly an ILS so roll steering is not allowed in the
final segment, even though it would be okay with RNAV.

[Stan Prevost[_1_]]

"Sam Spade" > wrote in message
...
> Stan Prevost wrote:
>>
> I got the straight scoop from a Garmin soothsayer. First, with a Garmin
> autopilot there would not be such a limitation. But, this manual is
> written on the presumption the aircraft has Brand K or Brand S autopilots
> that do have roll steering. But, those brands have to switch to CDI
> steering to fly an ILS so roll steering is not allowed in the final
> segment,

Interesting, but not totally clear. The implication is that the Garmin GPS
outputs roll steering commands derived from tracking the localizer signal.
Is that what the source was saying? Also, it implies that on the
non-brand-G autopilots, the entire ILS logic is based on using CDI steering
inputs. That may depend on whether the unit has "native" GPSS or add-on
GPSS. I have a brand-S unit without GPSS, but it can be added using the
external GPSS converter box that translates the roll steering commands into
inputs to the heading mode of the autopilot. I don't know how the add-on
box works on an ILS, probably can't be used.

> even though it would be okay with RNAV.

How about VOR?

[Sam Spade]

Stan Prevost wrote:

> "Sam Spade" > wrote in message
> ...
>
>>Stan Prevost wrote:
>>
>>I got the straight scoop from a Garmin soothsayer. First, with a Garmin
>>autopilot there would not be such a limitation. But, this manual is
>>written on the presumption the aircraft has Brand K or Brand S autopilots
>>that do have roll steering. But, those brands have to switch to CDI
>>steering to fly an ILS so roll steering is not allowed in the final
>>segment,
>
>
> Interesting, but not totally clear. The implication is that the Garmin GPS
> outputs roll steering commands derived from tracking the localizer signal.
> Is that what the source was saying? Also, it implies that on the
> non-brand-G autopilots, the entire ILS logic is based on using CDI steering
> inputs. That may depend on whether the unit has "native" GPSS or add-on
> GPSS. I have a brand-S unit without GPSS, but it can be added using the
> external GPSS converter box that translates the roll steering commands into
> inputs to the heading mode of the autopilot. I don't know how the add-on
> box works on an ILS, probably can't be used.
>
>
>>even though it would be okay with RNAV.
>
>
> How about VOR?

He may have mention that but, if he did, I forget already. ;-)

Wouldn't folks normally use RNAV instead of VOR? (unlike ILS where you
are required to use the actual LOC and G/S)

[Stan Prevost[_1_]]

"Sam Spade" > wrote in message
...
>
> Wouldn't folks normally use RNAV instead of VOR? (unlike ILS where you
> are required to use the actual LOC and G/S)

Probably, when there is a suitable RNAV approach available.

[Sam Spade]

Stan Prevost wrote:
> "Sam Spade" > wrote in message
> ...
>
>>Wouldn't folks normally use RNAV instead of VOR? (unlike ILS where you
>>are required to use the actual LOC and G/S)
>
>
> Probably, when there is a suitable RNAV approach available.

If there isn't a suitable RNAV approach available, then the VOR approach
should be "...or GPS."

[Stan Prevost[_1_]]

"Sam Spade" > wrote in message
...
> Stan Prevost wrote:
>> "Sam Spade" > wrote in message
>> ...
>>
>>>Wouldn't folks normally use RNAV instead of VOR? (unlike ILS where you
>>>are required to use the actual LOC and G/S)
>>
>>
>> Probably, when there is a suitable RNAV approach available.
>
> If there isn't a suitable RNAV approach available, then the VOR approach
> should be "...or GPS."

"Suitable".

Take my home field, for example. There used to be only a VOR/DME or GPS
cirling approach. Then the first RNAV straight-in approach went in and the
"or GPS" came off the other approach, as you say.

That RNAV approach comes in from the north, the VOR/DME comes in from the
west. Which one is most suitable depends on my direction of arrival. I'm
not going to fly 30 or more miles out of my way just to use the RNAV
approach, unless there is an advantage given the weather, making it more
suitable.

That's how I was using "suitable".

[Mark Hansen]

On 01/12/07 14:13, Stan Prevost wrote:
> "Sam Spade" > wrote in message
> ...
>> Stan Prevost wrote:
>>> "Sam Spade" > wrote in message
>>> ...
>>>
>>>>Wouldn't folks normally use RNAV instead of VOR? (unlike ILS where you
>>>>are required to use the actual LOC and G/S)
>>>
>>>
>>> Probably, when there is a suitable RNAV approach available.
>>
>> If there isn't a suitable RNAV approach available, then the VOR approach
>> should be "...or GPS."
>
> "Suitable".
>
> Take my home field, for example. There used to be only a VOR/DME or GPS
> cirling approach. Then the first RNAV straight-in approach went in and the
> "or GPS" came off the other approach, as you say.

So why would they kill the GPS Overlay approach in this case? It seems the GPS
overlay would still have value given the direction of arrival, as you state below.

>
> That RNAV approach comes in from the north, the VOR/DME comes in from the
> west. Which one is most suitable depends on my direction of arrival. I'm
> not going to fly 30 or more miles out of my way just to use the RNAV
> approach, unless there is an advantage given the weather, making it more
> suitable.
>
> That's how I was using "suitable".
>
>
>



--
Mark Hansen, PP-ASEL, Instrument Airplane
Cal Aggie Flying Farmers
Sacramento, CA

[Sam Spade]

Stan Prevost wrote:
> "Sam Spade" > wrote in message
> ...
>
>>Stan Prevost wrote:
>>
>>>"Sam Spade" > wrote in message
...
>>>
>>>
>>>>Wouldn't folks normally use RNAV instead of VOR? (unlike ILS where you
>>>>are required to use the actual LOC and G/S)
>>>
>>>
>>>Probably, when there is a suitable RNAV approach available.
>>
>>If there isn't a suitable RNAV approach available, then the VOR approach
>>should be "...or GPS."
>
>
> "Suitable".
>
> Take my home field, for example. There used to be only a VOR/DME or GPS
> cirling approach. Then the first RNAV straight-in approach went in and the
> "or GPS" came off the other approach, as you say.
>
> That RNAV approach comes in from the north, the VOR/DME comes in from the
> west. Which one is most suitable depends on my direction of arrival. I'm
> not going to fly 30 or more miles out of my way just to use the RNAV
> approach, unless there is an advantage given the weather, making it more
> suitable.
>
> That's how I was using "suitable".
>
>
>
Understood.

If someone had objected when they proposed to delete "or GPS" from the
circling approach, they probably would have left it alone.

The policy is ambiguous when it is not a straight-in replacing a
straight-in IAP.

[Stan Prevost[_1_]]

"Mark Hansen" > wrote in message
...
>> Take my home field, for example. There used to be only a VOR/DME or GPS
>> cirling approach. Then the first RNAV straight-in approach went in and
>> the
>> "or GPS" came off the other approach, as you say.
>
> So why would they kill the GPS Overlay approach in this case? It seems the
> GPS
> overlay would still have value given the direction of arrival, as you
> state below.
>
>>

I thought it was specified in the TERPS or associated policy, but Sam says
it is ambiguous in this case.

[Doug[_1_]]

I wasnt aware Garmin makes an autopilot. Is this new?

[Sam Spade]

Doug wrote:
> I wasnt aware Garmin makes an autopilot. Is this new?
>
Fairly new. Approved within the last year.