Intercepting the ILS

wrote:
If the pilot uses the glideslope for backup vertical guidance to give a
smooth transition to the final segment (while using the altimeter
readout outside the FAF to ensure he doesn't descend below 1800) then
what's wrong with that?


Nothing wrong with that.


That isn't really correct either. There's no necessity to monitor
the altimeter at SCK because there's no step-down fixes or other
crossing restrictions at issue. Above 1800 feet on the glideslope, the
glideslope is advisory, but the pilot is perforce satisfying the =1800
foot minimum altitude requirement. Below 1800 feet the glideslope
becomes primary. So in practical terms nothing happens at 1800 feet.
There's nothing to monitor. (OK. I know, you part 121 types have now
reached a point where the weather can below minimums without
necessitating a miss.)

At *Stockton* (the subject of the question), there is no legal issue.
At LAX on the Civet arrival, and other situations where there are
step-down altitudes on the localizer outside the PFAF, there is a
potential issue. The step down minima take precedence over the GS
altitude.

We are procedurally in violent agreement. Nonetheless, the G/S is not
primary prior to the PFAF, any minimum altitude constraints
notwithstanding. That is the legalese of Part 97. I am just the messenger.

We are procedurally in violent agreement. Nonetheless, the G/S is not
primary prior to the PFAF, any minimum altitude constraints
notwithstanding. That is the legalese of Part 97. I am just the messenger.

We're agreed that at SCK following the glide slope down from the 2000
foot vector altitude is the best procedure. We're also agreed that the
G/S is not primary outside the PFAF. Instead, one must abide by the
published altitudes - in this case we must remain above 1800 until this
PFAF. At SCK, this is logically guaranteed by our "best procedure".

However, I detect that your position is still that some sufficiently
zealous FAA inspector could violate me for using the G/S to descend to
1800. (otherwise how could the new instructor be "technically
correct"?). I disagree. If that is your position, please cite which
verse of Part 97 that this zealous inspector could attempt to violate
me on? Which regulation does our agreed best procedure not comply
with?

It's pointless discussing legality without reference to the law.

wrote:
We are procedurally in violent agreement. Nonetheless, the G/S is not
primary prior to the PFAF, any minimum altitude constraints
notwithstanding. That is the legalese of Part 97. I am just the messenger.


We're agreed that at SCK following the glide slope down from the 2000
foot vector altitude is the best procedure. We're also agreed that the
G/S is not primary outside the PFAF. Instead, one must abide by the
published altitudes - in this case we must remain above 1800 until this
PFAF. At SCK, this is logically guaranteed by our "best procedure".

However, I detect that your position is still that some sufficiently
zealous FAA inspector could violate me for using the G/S to descend to
1800. (otherwise how could the new instructor be "technically
correct"?). I disagree. If that is your position, please cite which
verse of Part 97 that this zealous inspector could attempt to violate
me on? Which regulation does our agreed best procedure not comply
with?

It's pointless discussing legality without reference to the law.

Look at an 8260-3 for any ILS approach. There is probably one or more
on the FAA's coordination web site today. The form is an individual
amendment to Part 97. It sets forth the courses, distances, minimum
altitudes, and location of P-FAF. It can be inferred from the context of
such regulatory document that the G/S is not the primary vertical
guidance mechanism prior to the P-FAF. That is the official view of
those who establish and implement the criteria.

This is reinforced by the fact that the AIM states that the lightening
bolt on NACO ILS charts (profile feather in Jepp charts) consitutes the
beginning of the ILS precision final approach segment. The FAA ILS
criteria for G/S obstacle clearance is not evaluated or used prior to
the PFAF. Intermediate and intial approach segment minimum barometric
altimetry fixes are used to define the vertical component of
intermediate and initial approach segments.

I agree with everything you just wrote. But, you have not addressed
my question. In what way does/can following the glideslope from 2000
to 1800 feet at SCK violate the regulatory implications of the SCK
ILS's 8260-3?

There is no rule that says "thou shalt not follow the G/S unless it
is primary". What the rules say is "thou shall not bust the published
altitude restrictions prior to the PFAF".

Since it isn't logically possible to violate the altitude
restrictions *in this instance* by following the G/S, it can't be
illegal to do so.

The regulatory basis is 91.175(a) which requires "Unless otherwise
authorized by the Administrator, when an instrument letdown to a civil
airport is necessary, each person operating an aircraft, except a
military aircraft of the United States, shall use a standard instrument
approach procedure prescribed for the airport in part 97 of this
chapter."

Part 97 does not prescribe pilot technique. It prescribes the tracks
and altitudes to be flown. If those are complied with, there's no
possible violation.

wrote:
I agree with everything you just wrote. But, you have not addressed
my question. In what way does/can following the glideslope from 2000
to 1800 feet at SCK violate the regulatory implications of the SCK
ILS's 8260-3?

In the specifics cited for Stockton there is no issue of legality. My
understanding was that the CFII in question was making a general
statement about the limitations of the G/S prior to the PFAF; that is,
it is advisory only. Although using it as advisory at Stockton and
using 1800 as the floor prior to the PFAF would be both legal and
permissiable technique, it will not work where there are intervening
stepdown fixes between the point at which the approach clearance is
received and the PFAF.

It is also permissible technique to disregard the G/S and simply drive
it down to 1,800 to intercept the G/S from below, assuming there is
sufficient distance to do that.

I surmised that the CFI was thinking in global terms, and failed to
provide a complete explanation. Then again, my understanding about what
was (in) the CFI's mind is fragile at best.

In general terms: it is not legal to use the G/S as primary prior to the
PFAF. That is an important concept for the pilot to understand. It has
been proven more than once that a lot of air carrier pilots don't
understand it.

"In the specifics cited for Stockton there is no issue of legality."

We're agreed then.

I had attempted to emphasize in my long series of messages to you that
*I* was talking about Stockton, whatever might have been in the CFI's
mind.

Ed

What I'm having difficulty reconciling is the following statements of
yours:

"If you can receive the G/S prior to the PFAF, it's only advisory in
any
case, so you are free to use it as you choose, provided you don't
violate any minimum segment altitude or stepdown fixes or any aspect of
an ATC clearance."

I totally agree.

"The new CFI is technically correct but the old CFI is far more
practical."
"In the case cited, the CFI is nitpicking but is nonetheless legally
correct."
"I agree that the CFI is procedurally wrong, although legally correct."


So how can you assert these, *given that in this instance* it is
physically and logically impossible to "violate any minimum segment
altitude or stepdown fixes or any aspect of
an ATC clearance", because
a) the ATC clearance was to maintain 2000 until intercepting the
localizer, and
b) the procedure was to descend on the glide slope to the minimum
segment altitude (1800) at which point the G/S becomes primary.

The point is that blindly following the glideslope has the potential
at places *other than SCK* of causing violations of published
altitudes. Following the G/S is not a violation per se, busting
published or ATC assigned altitudes is.
The CFI is not "technically correct" or "legally correct". What he
could have said, after the flight, is that if one chooses to follow the
G/S prior to the PFAF one needs to be mindful that published and ATC
assigned altitudes have to be complied with, but that at SCK that was
not an issue.

If an altitude is underlined, it is the MINIMUM altitude...
if an altitude is over-lined it is the maximum altitude. If
it is both under and over-lined the altitude is mandatory.


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


wrote in message
oups.com...
| What I'm having difficulty reconciling is the following
statements of
| yours:
|
| "If you can receive the G/S prior to the PFAF, it's only
advisory in
| any
| case, so you are free to use it as you choose, provided
you don't
| violate any minimum segment altitude or stepdown fixes or
any aspect of
| an ATC clearance."
|
| I totally agree.
|
| "The new CFI is technically correct but the old CFI is far
more
| practical."
| "In the case cited, the CFI is nitpicking but is
nonetheless legally
| correct."
| "I agree that the CFI is procedurally wrong, although
legally correct."
|
|
| So how can you assert these, *given that in this
instance* it is
| physically and logically impossible to "violate any
minimum segment
| altitude or stepdown fixes or any aspect of
| an ATC clearance", because
| a) the ATC clearance was to maintain 2000 until
intercepting the
| localizer, and
| b) the procedure was to descend on the glide slope to the
minimum
| segment altitude (1800) at which point the G/S becomes
primary.
|
| The point is that blindly following the glideslope has
the potential
| at places *other than SCK* of causing violations of
published
| altitudes. Following the G/S is not a violation per se,
busting
| published or ATC assigned altitudes is.
| The CFI is not "technically correct" or "legally
correct". What he
| could have said, after the flight, is that if one chooses
to follow the
| G/S prior to the PFAF one needs to be mindful that
published and ATC
| assigned altitudes have to be complied with, but that at
SCK that was
| not an issue.
|

"Jim Macklin" wrote

If an altitude is underlined, it is the MINIMUM altitude...
if an altitude is over-lined it is the maximum altitude. If
it is both under and over-lined the altitude is mandatory.

Jim, you've really got to make a better attempt at keeping up
with these threads.

Garner Miller posted this a few days back:
1800 is the minimum altitude; that's why it's underlined only on the
bottom of the number on the NACO charts. If it were mandatory, it
would have lines above and below (or the word "Mandatory" on Jepp
charts), and you would have to go down to 1800.

Bob Moore

I would try to monitor these groups 24/7 but sleep and other
tasks get in the way. Some posts get lost, some are
snipped, some don't include any of the previous post, sorry
if I post something that has been covered before.


--
James H. Macklin
ATP,CFI,A&P

--
The people think the Constitution protects their rights;
But government sees it as an obstacle to be overcome.
some support
http://www.usdoj.gov/olc/secondamendment2.htm
See http://www.fija.org/ more about your rights and duties.


"Bob Moore" wrote in message
. 122...
| "Jim Macklin" wrote
|
| If an altitude is underlined, it is the MINIMUM
altitude...
| if an altitude is over-lined it is the maximum altitude.
If
| it is both under and over-lined the altitude is
mandatory.
|
| Jim, you've really got to make a better attempt at keeping
up
| with these threads.
|
| Garner Miller posted this a few days back:
| 1800 is the minimum altitude; that's why it's underlined
only on the
| bottom of the number on the NACO charts. If it were
mandatory, it
| would have lines above and below (or the word "Mandatory"
on Jepp
| charts), and you would have to go down to 1800.
|
| Bob Moore