Change in AIM wording concerning procedure turn

"Ron Rosenfeld" wrote in message
...
On Sat, 01 Oct 2005 07:58:13 GMT, "Brad Salai"
wrote:

Are you saying that if the form (approach plate?) says no PT, then no PT
is
required, which I understand and agree with, or are you saying that if
the
form is silent, then a PT is required in all cases, which I'm less sure
of?


I should only speak with regard to Jepp charting conventions as those are
the approach plates I use.

If a route or segment states NoPT, then no procedure turn is required OR
authorized. If you want to do a procedure turn, you must obtain ATC
permission.

If a procedure turn is charted, then it is required unless one of the
previously discussed exceptions apply (e.g. NoPT; vectors to final; timed
approaches).

If a procedure turn is NOT charted, then it is NOT authorized.



I looked at random at a bunch of NOCA forms, and there are lots of
instances
of approaches from IAF's that clearly say no PT. These seem all to be
situations where I would say (based on pilot judgment) that a course
reversal is not required. There are also lots of examples, most, or all
on
courses outbound on the final approach heading, that show a PT barb,
which I
take as indicating that a PT is mandatory. on the new GPS approaches
where
the heading into the fix is 90 degrees, there are indications that no PT
is
required, other than that, I couldn't find any indication in ambiguous
situations (90 degrees or more), of whether a PT is required or not. It
looks to me as if, other than the pretty clear case where you are
outbound
on the final approach heading, that they never indicate when a PT is
required, only when it is not. That means, I think, that you are going to
have to determine whether "a course reversal is required," to know
whether
you need to make a PT.

I believe the determination of "course reversal required" is to be made by
the procedure designer, and not the pilot.



Is there a definition somewhere of what a course reversal is, or even
better, when a course reversal is required?

TERPS (I think it's 8260.3 and 8260.19 or something like that)


If you happen to have it, or can get it, look at the VOR RWY 13 approach
to
ACY (Atlantic City). A holding pattern is depicted at the IAF, but there
is
no guidance as to when it should be used. Doesn't that mean that the
pilot
needs to determine based on his heading into the IAF whether a course
reversal is required, and if it is, then he has to do a PT, either a
conventional PT, or a course reversal by way of the depicted hold? Or are
you saying that you need to enter the hold from all directions, go around
at
least once, and then continue in, in which case, isn't the "when a course
reversal is required" language redundant?

Since the racetrack pattern is charted, the procedure turn must be flown
as
charted (e.g. the type of turn and where to start it, in this instance, is
NOT pilot choice). Again, according to Jepp charting conventions, this PT
would have to be flown unless you were on radar vectors to the final
approach course (or if there were timed approaches going on). I'm not
familiar with that area, or how ATC works there, but I would expect that
radar coverage would be pretty good there and, unless there's some traffic
related reason off to the NW and not on the approach chart, that you would
be getting radar vectors to final if you were approaching from the NW (or
maybe even from other directions).

And there may be TERP's related reasons for that required course reversal,
also. The only charted course to the IAF is from ACY VOR with an MEA of
1900'; the MSA for that sector is 2100'. If you were to cross BURDK at
either of those altitudes, in order to execute a straight-in approach, you
would exceed the maximum TERPS allowed descent gradient of 400 ft/nm for a
straight-in approach. (1900-75)/4.5 = 405.6 ft/nm. So, the procedure
designer determined that a course reversal was required in order to
publish
straight-in minimums.

I wouldn't have guessed it from the language, but what you say makes a lot
of sense, and especially with the approach gradient issue, seems like the
safest way, so I at least will do it that way.

Just to be certain what you mean, coming in from the NW, straignt in, cross
BURDK, enter the hold and decend from 1900 to 1600 when established on the
inbound leg before reaching BURDK the second time? All this assumes no radar
vectors.

Thanks.

Brad

"Brad Salai" wrote in message
...

"Gary Drescher" wrote in message
...

No, the ambiguity I'm pointing out isn't just a matter of the vagueness
of
"course reversal". The new AIM phrasing is ambiguous as to whether the
enumerated conditions are meant only as an *elaboration* of what it means
for a course reversal to be unnecessary (in which case a charted PT is
required unless the enumerated conditions are met), or whether a lack of
need for a course-reversal is meant as an *addition* to the enumerated
conditions (in which case the PT might not be required even if none of
the
enumerated conditions are met).

I think its the second case. Here is the language again:

The procedure turn or hold in lieu of procedure turn is a required
maneuver when it is necessary to perform a course reversal.
The procedure turn is not required when the symbol "No PT" is shown,
when
RADAR VECTORING to the final approach course is provided, when
conducting a timed approach, or when the procedure turn is not
authorized.

The first sentence doesn't make any sense unless there are situations
where
"it is necessary to perform a course reversal."

Sure.

If that's true, then the
second sentence must be exceptions to the first, that is, situations where
it would appear "necessary to perform a course reversal" but a PT is not
required.

Yes and no. Yes, the second sentence lists situations in which a charted PT
is not required (the PT does not necessarily "appear necessary" in those
situations, though, except to the extent that simply being charted might
make them appear necessary). But no, the second sentence doesn't list
exceptions to the if-then assertion made by the first sentence; that is, the
second sentence does not list situations in which there is a necessary
course reversal but not a required PT.

If the intent were that a PT is required unless one of the four exceptions
applied, they would (or at least should) have said:

The procedure turn or hold in lieu of procedure turn is a required
maneuver unless the symbol "No PT" is shown, when
RADAR VECTORING to the final approach course is provided, when
conducting a timed approach, or when the procedure turn is not
authorized.
which would have been clear and unambiguous.

Yes, if that was their intent, they should have used that wording, or else
they should have used the "elaboration" paraphrase I proposed earlier in the
thread. But if their intent was as you believe, then they should have used
the "addition" paraphrase I proposed, which would also have been clear and
unambiguous. In fact, though, they used neither, and their chosen phrasing
was not clear or unambiguous.

General rules of construction
suggest that you should interpret the language so that the first sentence
is
not redundant or meaningless,

Correct.

which leads to the second interpretation, what G. Drescher calls
*addition*.

No, because my "elaboration" interpretation *also* allows the first sentence
to be meaningful and not redundant. Here is the "elaboration" paraphrase
again:

"The procedure turn is a required maneuver, unless one of the following
conditions obtains, in which case a course reversal is unnecessary: 1) the
symbol 'NoPT' is shown; 2) radar vectoring to the final approach course is
provided; 3) you are conducting a timed approach; or 4) the procedure turn
is not authorized."

In this paraphrase, the sentence in question is construed to be explaining
the rationale for the exceptions--namely, that the reason the PT maneuver
isn't required in the exceptional cases is that a reversal of course is
deemed unnecessary in those cases. That explanation may not be profound, but
it is neither meaningless nor redundant.

So the AIM wording is ambiguous. But if we look beyond the wording to the
underlying logic, then the "elaboration" interpretation makes more sense
than the "addition" interpretation that you favor. That's because the
"addition" interpretation effectively expects the pilot to act as a
real-time approach designer, making her own decision as to the necessity for
a course reversal (presumably in compliance with the TERPS criteria, which
are not even part of the standard pilot curriculum). In contrast, the
"elaboration" interpretation expects the TERPS criteria to be used by the
approach-chart designer, and simply expects the pilot to comply with the
chart.

The FAA email that Tim posted earlier in the thread confirms that the FAA's
intent is indeed the "elaboration" interpretation (but of course that's not
authoritative until it appears in some official source).

--Gary

"Gary Drescher" wrote in message
...
"Brad Salai" wrote in message
...

"Gary Drescher" wrote in message
...

No, the ambiguity I'm pointing out isn't just a matter of the vagueness
of
"course reversal". The new AIM phrasing is ambiguous as to whether the
enumerated conditions are meant only as an *elaboration* of what it
means
for a course reversal to be unnecessary (in which case a charted PT is
required unless the enumerated conditions are met), or whether a lack
of
need for a course-reversal is meant as an *addition* to the enumerated
conditions (in which case the PT might not be required even if none of
the
enumerated conditions are met).

I think its the second case. Here is the language again:

The procedure turn or hold in lieu of procedure turn is a required
maneuver when it is necessary to perform a course reversal.
The procedure turn is not required when the symbol "No PT" is shown,
when
RADAR VECTORING to the final approach course is provided, when
conducting a timed approach, or when the procedure turn is not
authorized.

The first sentence doesn't make any sense unless there are situations
where
"it is necessary to perform a course reversal."

Sure.

If that's true, then the
second sentence must be exceptions to the first, that is, situations
where
it would appear "necessary to perform a course reversal" but a PT is not
required.

Yes and no. Yes, the second sentence lists situations in which a charted
PT
is not required (the PT does not necessarily "appear necessary" in those
situations, though, except to the extent that simply being charted might
make them appear necessary). But no, the second sentence doesn't list
exceptions to the if-then assertion made by the first sentence; that is,
the
second sentence does not list situations in which there is a necessary
course reversal but not a required PT.

If the intent were that a PT is required unless one of the four
exceptions
applied, they would (or at least should) have said:

The procedure turn or hold in lieu of procedure turn is a required
maneuver unless the symbol "No PT" is shown, when
RADAR VECTORING to the final approach course is provided, when
conducting a timed approach, or when the procedure turn is not
authorized.
which would have been clear and unambiguous.

Yes, if that was their intent, they should have used that wording, or else
they should have used the "elaboration" paraphrase I proposed earlier in
the
thread. But if their intent was as you believe, then they should have used
the "addition" paraphrase I proposed, which would also have been clear and
unambiguous. In fact, though, they used neither, and their chosen phrasing
was not clear or unambiguous.

General rules of construction
suggest that you should interpret the language so that the first
sentence
is
not redundant or meaningless,

Correct.

which leads to the second interpretation, what G. Drescher calls
*addition*.

No, because my "elaboration" interpretation *also* allows the first
sentence
to be meaningful and not redundant. Here is the "elaboration" paraphrase
again:

"The procedure turn is a required maneuver, unless one of the following
conditions obtains, in which case a course reversal is unnecessary: 1) the
symbol 'NoPT' is shown; 2) radar vectoring to the final approach course is
provided; 3) you are conducting a timed approach; or 4) the procedure turn
is not authorized."

In this paraphrase, the sentence in question is construed to be explaining
the rationale for the exceptions--namely, that the reason the PT maneuver
isn't required in the exceptional cases is that a reversal of course is
deemed unnecessary in those cases. That explanation may not be profound,
but
it is neither meaningless nor redundant.

So the AIM wording is ambiguous. But if we look beyond the wording to the
underlying logic, then the "elaboration" interpretation makes more sense
than the "addition" interpretation that you favor. That's because the
"addition" interpretation effectively expects the pilot to act as a
real-time approach designer, making her own decision as to the necessity
for
a course reversal (presumably in compliance with the TERPS criteria, which
are not even part of the standard pilot curriculum). In contrast, the
"elaboration" interpretation expects the TERPS criteria to be used by the
approach-chart designer, and simply expects the pilot to comply with the
chart.

The FAA email that Tim posted earlier in the thread confirms that the
FAA's
intent is indeed the "elaboration" interpretation (but of course that's
not
authoritative until it appears in some official source).

--Gary

I've either persuaded myself, or been persuaded that the "elaboration"
construction is the safest, and the email suggests that it is what was
intended, but it really doesn't follow from the original language. Your
paraphrase leaves out "when it is necessary to perform a course reversal"
from the first sentence where it actually appears, and puts in in the
second, where it actually says that a PT is not necessary so that it reads
"where a course reversal is not necessary" which it didn't say.
If they had had you available to help them out when they drafted this, it
would have saved us all a lot of time.
No matter what it says, as I said before, I'm going to fly by the
elaboration construction, but no way do I agree that the words say that.

On Sat, 01 Oct 2005 13:33:03 GMT, "Brad Salai"
wrote:

I wouldn't have guessed it from the language, but what you say makes a lot
of sense, and especially with the approach gradient issue, seems like the
safest way, so I at least will do it that way.

Just to be certain what you mean, coming in from the NW, straignt in, cross
BURDK, enter the hold and decend from 1900 to 1600 when established on the
inbound leg before reaching BURDK the second time? All this assumes no radar
vectors.


Well, coming from the NW there's no charted route until you get to BURDK of
which I am aware. So, unless ATC can clear you to a lower altitude, your
minimum IFR altitude would be controlled by 91.177 (ii) "In any other case,
an altitude of 1,000 feet above the highest obstacle within a horizontal
distance of 4 nautical miles from the course to be flown." 1900 would
probably be safe once you got to the area of the procedure turn, but that's
not precisely charted. If I were doing this from the NW, non-radar, I
would probably maintain at or above the MSA, which is a charted altitude,
until BURDK; then descend to 1900 outbound and 1600 inbound. (1900 might
be both safe and legal in the area to the NW that is not on the approach
plate, but I'd have to study sectionals to be sure).

Having said that, your clearance from ATC should give you the information.
Coming from the NW, it should go something like "Maintain at or above xxxx
ft until (some_fix); cleared for the VOR Rwy 13 approach". If you are
doing this non-radar, your clearance will likely be to ACY and not to
BURDK.



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

I'm still confused. Assuming the following facts, how would you fly
the ILS RWY 28R at KSFO
(http://www.naco.faa.gov/d-tpp/0510/00375I28R.PDF), which has a holding
pattern depicted in lieu of PT, and no indication that radar is
required?

Assumptions:
1) Upon departure, you were cleared to SFO, as filed;
2) your filed route takes you through the MENLO IAF (I don't know if
there's an airway through MENLO, but assume you got there for the sake
of argument);
3) you lost radio contact before your arrival at MENLO; and
4) you arrive at MENLO at 4000 feet and at your filed ETA.

Here's how I'd fly the procedure - will I be in violation of any FARs,
even given the interpretation of the AIM change that is proposed here?
1) Cross MENLO at 4000, descend to 3200 and continue to CEPIN;
2) As I approach CEPIN and as the localizer comes alive and starts
moving toward center, begin turning left to intercept localizer - note
that I will initially have almost a 50 degree intercept - and begin
descent to 1800 feet; and
3) at AXMUL, intercept glideslope and continue descent.

Why would I turn right at CEPIN or even at MENLO to spend some time in
the hold at DUMBA, except perhaps if I arrived prior to my filed ETA?

My layman's interpretation of the language would be as follows:

1) "A procedure turn is the maneuver prescribed *when it is necessary
to
perform a course reversal*..."

2) [When it is necessary to perform a course reversal,] "The procedure
turn or hold in lieu of procedure turn is a required maneuver."

3) [Even when it is necessary to perform a course reversal,] "The
procedure turn is not required when the symbol "No PT" is shown, when
RADAR VECTORING to the final approach course is provided, when
conducting a timed approach, or when the procedure turn is not
authorized."

This begs the question, "when is it necessary to perform a course
reversal?" Someone mentioned a descent of 300 feet or a turn of more
than 30 degrees according to TERPS (not according to anything we
studied to get our IFR ticket, as far as I recall), though that doesn't
seem right to me. I think even a 90 degree intercept or 1000 feet (or
more) of descent may be okay if you're far enough from the FAF.

"Brad Salai" wrote in message
...

"Gary Drescher" wrote in message
Here is the "elaboration" paraphrase again:

"The procedure turn is a required maneuver, unless one of the following
conditions obtains, in which case a course reversal is unnecessary: 1)
the
symbol 'NoPT' is shown; 2) radar vectoring to the final approach course
is
provided; 3) you are conducting a timed approach; or 4) the procedure
turn
is not authorized."

I've either persuaded myself, or been persuaded that the "elaboration"
construction is the safest, and the email suggests that it is what was
intended, but it really doesn't follow from the original language.

Not unambiguously, no. I claim only that it's one of two reasonable
interpretations.

Your
paraphrase leaves out "when it is necessary to perform a course reversal"
from the first sentence where it actually appears, and puts in in the
second, where it actually says that a PT is not necessary so that it reads
"where a course reversal is not necessary" which it didn't say.

Right, and I think that's comaptible with the original phrasing. To put it
another way, I think the original sentences "The PT... is a required
maneuver when it is necessary to perform a course reversal. The PT is not
required when..." could be taken to mean "When we judge that it is necessary
for you to perform a course reversal, we require you to execute a PT. (We
convey this requirement by charting a PT on the approach plate.) However, a
charted PT is not required when..."

No matter what it says, as I said before, I'm going to fly by the
elaboration construction,

As will about half of all pilots, it seems. Now we just have to persuade
the other half.

--Gary

On 1 Oct 2005 18:13:06 -0700, "rps" wrote:

I'm still confused. Assuming the following facts, how would you fly
the ILS RWY 28R at KSFO
(http://www.naco.faa.gov/d-tpp/0510/00375I28R.PDF), which has a holding
pattern depicted in lieu of PT, and no indication that radar is
required?

Assumptions:
1) Upon departure, you were cleared to SFO, as filed;
2) your filed route takes you through the MENLO IAF (I don't know if
there's an airway through MENLO, but assume you got there for the sake
of argument);
3) you lost radio contact before your arrival at MENLO; and
4) you arrive at MENLO at 4000 feet and at your filed ETA.

Here's how I'd fly the procedure - will I be in violation of any FARs,
even given the interpretation of the AIM change that is proposed here?
1) Cross MENLO at 4000, descend to 3200 and continue to CEPIN;
2) As I approach CEPIN and as the localizer comes alive and starts
moving toward center, begin turning left to intercept localizer - note
that I will initially have almost a 50 degree intercept - and begin
descent to 1800 feet; and
3) at AXMUL, intercept glideslope and continue descent.

Why would I turn right at CEPIN or even at MENLO to spend some time in
the hold at DUMBA, except perhaps if I arrived prior to my filed ETA?

I'm not as familiar with NACO charts as with Jepp charts (and I don't have
a Jepp chart for that approach) but I would not even consider turning right
at CEPIN or MENLO to go to DUMBA. It seems to me that the procedure track
from the MENLO IAF does not proceed via DUMBA. This seems apparent from
the charting; but also note that the MEA for the route from MENLO to CEPIN
is lower than the MEA in the hold at DUMBA.

So far as doing a hold if you arrived ahead of your ETA, in accord with the
regulations regarding radio failure, I believe you should be holding at
MENLO. Although, the situation may well be considered an emergency,
depending on what you are flying, and I might choose to skip this provision
of the regulations for safety reasons.


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

"Roy Smith" wrote in message
...

The problem comes in when you're on a random route such as direct to
the IAF/FAF. You can be between two airways converging on the IAF,
both of which are marked NoPT (and at the same altitude marked for
those routes), and yet you're not on a NoPT segment yourself. I think
most people would agree that it's reasonable to assume that not doing
a PT in this case is perfectly safe. The question which leads to
endless debate is whether it's legal or not.


How did you come to be on that random route? You say you're not on an
airway, so you must be either within usable navaid limits or in radar
contact. If you're within usable navaid limits, why isn't the route also
published with a NoPT? If you're in radar contact, why weren't you vectored
for the approach, which would negate flying the PT?

"Gary Drescher" wrote in message
...

You'll find no FAR that explicitly requires performing a charted PT
*regardless* of whether or not the PT meets the TERPS criteria. That
doesn't make all the PTs optional, does it?


Of course not.



No, but in some cases it offers the only readily available definitive FAA
interpretation of key regulations. That's what it's trying to do in this
case, but the chosen wording is unfortunately ambiguous.


The regulation seems pretty clear to me in this case.