Flying Mag Clueless about LPV and NACO

Airbus wrote:
In article , says...


John T wrote:

"Sam Spade" wrote in message



Their bone was with NACO LPV charts because they don't understand
NACO's way of portraying the P-FAF with a lightening bolt. Apparently you
do. Also, apparently a lot of their readers don't.


What's the demographic of the typical "Flying" reader?


Armchair pilots I suppose.



Sincerely doubt it.
Why don't you write to them instead of writing about it here?
Pilots are supposed to be goal oriented - only balloon pilots are hot winded. .
.

(I'm like Mac on this one - only use Jepp charts so I have no idea how off the
wall you are on this. Write to them directly and you are sure to win your
reward or meet your match.)


Oh, I did write them about it.

They erected a giant stone wall.

Here is the entire exchange:

http://www.terps.com/Flying/Flying.pdf

I like reading Richard Collins's stuff but he was a bit of a wise-ass in
that exchange. It seems to me the fundamental issue is their preference to
the Jeppesen way of charting step down segments versus the NACO way. I'm
surprised you didn't stress the underlining of the segment altitudes as
NACO's way of identifying the level-off altitudes in a LNAV-only approach as
opposed to the Jepp way of depicting the step-downs visually with the line.

That said, with the advent of LPV and the increased frequency of one chart
showing both precision* and non-precision approaches, Jeppesen's method will
create less confusion to the average pilot (especially in bumpy IMC). In a
pure "legalese" view, you are correct in that the NACO chart is not charting
the approach "incorrectly." However, I think they have a legitimate gripe in
taking issue with the way NACO charts the step-downs in GPS approaches with
mixed LPV-LNAV/VNAV-LNAV minima. What makes their case a bit stronger is the
fact the WAAS GPS units will default to the LPV approach as long as the
HAL/VAL is within limits and (at least in the 430/530 series) there is no
way of manually choosing the LNAV-only approach. Therefore the majority of
the time the approach will be flown closer to the Jeppesen visual
representation rather than the NACO's representation.

Using the CRQ RNAV(GPS) RWY 24 chart you used in the email exchange, a
typical LPV approach will have the aircraft level-off at 3,100 ft between
KANEC and JABAL with glideslope intercept occurring at JABAL. The NACO chart
shows this transition only with the [thin] lightening bolt whereas the Jepp
shows it quite clearly with the visual step down depiction. Like you stated,
neither way is wrong but Jepp is just clearer IMO.

Question for you. You say that the sloping outside JABAL is "advisory only."
Given the typical GPS T-configuration, would anyone be expected as standard
practice to actually intercept the glideslope at KANEC? Also, If you're on
the glideslope at JABAL, your altitude should be 3,100 feet (or close to it)
correct? Therefore, if you choose to follow the advisory glideslope at
KANEC, would your altitude be 3,800 feet? If one can not expect to
cross-check their altitude at KANEC with the depicted altitude of 3,800 ft.,
it would be another misleading representation (notice I didn't say
"incorrect").

I look forward to your point of view.

Regards,

Marco

* I realize that LPV approaches are not considered "precision" in some
contexts, thus the asterisk.


"Sam Spade" wrote in message
...
Airbus wrote:
In article , says...


John T wrote:

"Sam Spade" wrote in message



Their bone was with NACO LPV charts because they don't understand
NACO's way of portraying the P-FAF with a lightening bolt. Apparently
you do. Also, apparently a lot of their readers don't.


What's the demographic of the typical "Flying" reader?


Armchair pilots I suppose.



Sincerely doubt it. Why don't you write to them instead of writing about
it here?
Pilots are supposed to be goal oriented - only balloon pilots are hot
winded. . .

(I'm like Mac on this one - only use Jepp charts so I have no idea how
off the wall you are on this. Write to them directly and you are sure to
win your reward or meet your match.)


Oh, I did write them about it.

They erected a giant stone wall.

Here is the entire exchange:

http://www.terps.com/Flying/Flying.pdf

Marco Leon wrote:
I like reading Richard Collins's stuff but he was a bit of a wise-ass in
that exchange. It seems to me the fundamental issue is their preference to
the Jeppesen way of charting step down segments versus the NACO way. I'm
surprised you didn't stress the underlining of the segment altitudes as
NACO's way of identifying the level-off altitudes in a LNAV-only approach as
opposed to the Jepp way of depicting the step-downs visually with the line.

That said, with the advent of LPV and the increased frequency of one chart
showing both precision* and non-precision approaches, Jeppesen's method will
create less confusion to the average pilot (especially in bumpy IMC). In a
pure "legalese" view, you are correct in that the NACO chart is not charting
the approach "incorrectly." However, I think they have a legitimate gripe in
taking issue with the way NACO charts the step-downs in GPS approaches with
mixed LPV-LNAV/VNAV-LNAV minima. What makes their case a bit stronger is the
fact the WAAS GPS units will default to the LPV approach as long as the
HAL/VAL is within limits and (at least in the 430/530 series) there is no
way of manually choosing the LNAV-only approach. Therefore the majority of
the time the approach will be flown closer to the Jeppesen visual
representation rather than the NACO's representation.

Using the CRQ RNAV(GPS) RWY 24 chart you used in the email exchange, a
typical LPV approach will have the aircraft level-off at 3,100 ft between
KANEC and JABAL with glideslope intercept occurring at JABAL. The NACO chart
shows this transition only with the [thin] lightening bolt whereas the Jepp
shows it quite clearly with the visual step down depiction. Like you stated,
neither way is wrong but Jepp is just clearer IMO.

Question for you. You say that the sloping outside JABAL is "advisory only."
Given the typical GPS T-configuration, would anyone be expected as standard
practice to actually intercept the glideslope at KANEC? Also, If you're on
the glideslope at JABAL, your altitude should be 3,100 feet (or close to it)
correct? Therefore, if you choose to follow the advisory glideslope at
KANEC, would your altitude be 3,800 feet? If one can not expect to
cross-check their altitude at KANEC with the depicted altitude of 3,800 ft.,
it would be another misleading representation (notice I didn't say
"incorrect").

I look forward to your point of view.

Regards,

Marco
Last first: LPV IAPs are indeed precision IAPs.

And, let me add, my entire professional life has been with Jeppesen charts.

But, I work with TERPS and the FAA a lot. NACO charts are the FAA's
method of charting IAP source. So, if they were wrong, they need to be
called on it. But, if is an issue of style, and Collins feels strongly
enough about it, he is welcome to attend the semi-annual FAA/Industry
Aeronautical Charting Forum, even submitting an issue paper in advance.
(His attendance has been mentioned to him before).

At CRQ let's say I am flying the terminal routing from OCN. I would not
receive an LPV G/S on a Garmin 400/500W series navigator until crossing
KANAC at 3800. the LPV G/S would be a full fly-up because the G/S at
KANEC would be just over 5100. (So, there is no cross-check info for
that provided by either Jepp or NACO, nor should there be.) I can
choose to maintain 3800 until G/s intercept (just over 2 miles prior to
JABEL, or descend to 3100 to intercept at JABAL. Will the G/S be
precisely 3100 at JABEL? That depends on altimeter error, just like
with an ILS.

"Sam Spade" wrote in message
...
Last first: LPV IAPs are indeed precision IAPs.

And, let me add, my entire professional life has been with Jeppesen
charts.

But, I work with TERPS and the FAA a lot. NACO charts are the FAA's
method of charting IAP source. So, if they were wrong, they need to be
called on it. But, if is an issue of style, and Collins feels strongly
enough about it, he is welcome to attend the semi-annual FAA/Industry
Aeronautical Charting Forum, even submitting an issue paper in advance.
(His attendance has been mentioned to him before).

I've always wondered how much NACO would be able to copy Jeppesen (i.e. the
Briefing Strip) and not get sued for copyright infringement

At CRQ let's say I am flying the terminal routing from OCN. I would not
receive an LPV G/S on a Garmin 400/500W series navigator until crossing
KANAC at 3800. the LPV G/S would be a full fly-up because the G/S at
KANEC would be just over 5100. (So, there is no cross-check info for that
provided by either Jepp or NACO, nor should there be.) I can choose to
maintain 3800 until G/s intercept (just over 2 miles prior to JABEL, or
descend to 3100 to intercept at JABAL. Will the G/S be precisely 3100 at
JABEL? That depends on altimeter error, just like with an ILS.

If you'll be at 5,100 feet at KANEC, then (again in my opinion) the visual
depiction of a "glideslope" intersecting the waypoint at 3,800 feet is
misleading. I realize the G/S intersect at JABEL will be subject to
altimeter error which is why I made sure to qualify it with "or close to
it."

Marco

Marco Leon wrote:


I've always wondered how much NACO would be able to copy Jeppesen (i.e. the
Briefing Strip) and not get sued for copyright infringement

The briefing strip came about as a result of a government study (Volpe,
DOT). So, that wasn't invented by Jeppesen.


If you'll be at 5,100 feet at KANEC, then (again in my opinion) the visual
depiction of a "glideslope" intersecting the waypoint at 3,800 feet is
misleading. I realize the G/S intersect at JABEL will be subject to
altimeter error which is why I made sure to qualify it with "or close to
it."

Marco



No, I said the G/S would be 5,100 at KANEC, but in my example coming
from the north the airplane was at 3,800, thus the intercept 4 miles
west of KANEC.

Sam Spade wrote:

Last first: LPV IAPs are indeed precision IAPs.

The AIM refers to them as APV approaches, approaches with vertical
guidance. For alternate purposes, they're to be considered non-
precision.

Greg Esres wrote:
Sam Spade wrote:

Last first: LPV IAPs are indeed precision IAPs.

The AIM refers to them as APV approaches, approaches with vertical
guidance. For alternate purposes, they're to be considered non-
precision.

First, the term APV is applied to any FAA approach with vertical
guidance that does not meet the precision approach requirements of ICAO
Annex 10. The FAA does not agree with Annex 10 because the FAA
considers LPV IAPs to be precision IAPs and, in fact, use ILS obstacle
clearance containment areas for obstacle protection.

An LDA with a G/S is also an APV because it clearly does not meet any
definition of a precision IAP.

As to the alternate requirements, your statement is incomplete. You
cannot plan to use the precision line of minimums on a WAAS IAP for
alternate planning purposes. But, if WAAS LPV is available when
arriving at the alternate you may use the LPV *precision* line of minima.

Sam Spade wrote:

FAA considers LPV IAPs to be precision IAP

The FAA that writes the AIM says differently:

===================
1-1-20.
....

A new type of APV approach procedure, in addition to LNAV/VNAV, is
being implemented to take advantage of the lateral precision provided
by WAAS. This angular lateral precision, combined with an electronic
glidepath allows the use of TERPS approach criteria very similar to
that used for present precision approaches, with adjustments for the
larger vertical containment limit. The resulting approach procedure
minima, titled LPV (localizer performance
with vertical guidance)...
================

But, if WAAS LPV is available when arriving at the alternate you may
use the LPV *precision* line of minima.

Yes, that's obvious, but it still underlines that the FAA doesn't not
consider the LPV approach to be a precision approach as far as the
user is concerned.

Greg Esres wrote:
Sam Spade wrote:

FAA considers LPV IAPs to be precision IAP

The FAA that writes the AIM says differently:

===================
1-1-20.
...

A new type of APV approach procedure, in addition to LNAV/VNAV, is
being implemented to take advantage of the lateral precision provided
by WAAS. This angular lateral precision, combined with an electronic
glidepath allows the use of TERPS approach criteria very similar to
that used for present precision approaches, with adjustments for the
larger vertical containment limit. The resulting approach procedure
minima, titled LPV (localizer performance
with vertical guidance)...
================

But, if WAAS LPV is available when arriving at the alternate you may
use the LPV *precision* line of minima.

Yes, that's obvious, but it still underlines that the FAA doesn't not
consider the LPV approach to be a precision approach as far as the
user is concerned.

The FAA is covering its butt with ICAO. Technically, there are now
three types of IAPs.

1. Precision

2. APV

3. Non-precision

1 and 2 are flown identically when the APV is an RNAV IAP with LPV or
VNAV minimums. They both have DAs.

If it walks like a duck and quacks like a duck.....

When you fly an LPV (or teach it) do you teach precision or
non-precision procedures and flap settings, etc, for the final approach
segment?

In article , says...


Airbus wrote:
In article , says...


John T wrote:


Oh, I did write them about it.

They erected a giant stone wall.




Maclellan says some readers took him to task for claiming that an LPV was flown
exactly like an ILS. He and Collins surmised that some of the confusion could
be attributed to charting ambiguities on NACO charts. This indeed seems to be a
pet peeve of theirs, as Collins goes into it in one of the Sporty's videos as
well, and uses the same DMW approach as an example, if I recall.

The gripe seems to be that the profile view in the NACO chart does not show a
stepdown, as the Jepp does, neatly intercepting the glideslope from below. In
purely graphical terms, they have a point. An architect would agree it's
misleading, and the continuous, sloping line on the NACO chart suggests a fixed
descent rate from the IF would have you magically intercept the glideslope at
the right place and altitude and even on the correct slope, which of course is
not true, and is not the way it's flown.

You argue this is a conventional depiction, unchanged from the way they have
always depicted ILS's and simply knowing the convention allows the pilot to fly
it correctly and intercept at the right altitude at the lightning bolt. You
certainly have a point as well, but if it were that clear and simple perhaps
there would have been fewer confused readers writing to Mac because they didn't
understand how to fly the approach.

We don't know what those readers wrote, but perhaps he has some reason to
believe their confusion stems in part from an imperfect charting convention,
which could stand some clarification.