When to descend

On Tue, 09 Oct 2007 14:27:34 -0500, Mitty wrote:

Why would you read anything into it? I'm not being argumentative; I just don't
understand why you would not "maintain 4000' until established" and at that
point begin to descend. Or, if you didn't like the profile, get back to ATC and
"request lower."

When you enter the TAA, you ARE established.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

Dane Spearing wrote:
In article , Bee wrote:

Steven P. McNicoll wrote:


"Dan Luke" wrote in message
...


You are coming from northeast of SFB. ATC says "Cleared direct UDUZI,
maintain 4000' until established, cleared RNAV 9L approach."

http://www.naco.faa.gov/d-tpp/0710/00917R9L.PDF


When do you descend below 4,000 and to what altitude?



30 miles from UDUZI, 2700 MSL.



correct.


Hmmmmm....I'm not sure I buy this. The clearance stated "...maintain 4000'
*until established*..." which to me says that I'm to remain at 4000' until
I am on a *charted* section of the approach. Simply being in the TAA
does not mean I'm on a charted section of the approach. For this clearance,
I would say I'm on a charted section of the approach after crossing the IAF
(UDUZI). I would not descend below 4000' until after crossing UDUZI, and
then I would descent to 2000' as depicted. Or am I being too conservative
here?

-- Dane

Too conservative and wrong. The altitudes within a TAA are operational
altitudes, otherwise they would not contain an altitude with an underscore.

Ron Rosenfeld wrote:

On Tue, 9 Oct 2007 10:09:26 -0500, "Dan Luke"
wrote:


You are coming from northeast of SFB. ATC says "Cleared direct UDUZI,
maintain 4000' until established, cleared RNAV 9L approach."

http://www.naco.faa.gov/d-tpp/0710/00917R9L.PDF


When do you descend below 4,000 and to what altitude?


Coming from the NE, you may descend to 2700' after crossing 30 NM from
UDUZI (in the Left Base Area of the TAA).

Since there seems to be some variation in the responses to your question,
here is the relevant AIM paragraph:

Pilots entering the TAA and cleared by air traffic control, are expected
to proceed directly to the IAF associated with that area of the TAA at the
altitude depicted, unless otherwise cleared by air traffic control. Cleared
direct to an Initial Approach Fix (IAF) without a clearance for the
procedure does not authorize a pilot to descend to a lower TAA altitude.

Perhaps the controller should have said "...maintain 4000 until entering
the TAA". But I think his intent is clear. If he wanted you at 4000 until
crossing UDUZI, he should have either stated that explicitly, or not
cleared you for the approach.
Ron (EPM) (N5843Q, Mooney M20E) (CP, ASEL, ASES, IA)

I guess the AIM and the IPH need to state "A TAA straight-in, left base,
or right base area is the regulatory equivalent of a published approach
segment." Otherwise, the uncertainty and sharpshooting is endless. ;-)

Mitty wrote:



On 10/9/2007 1:20 PM, Steven P. McNicoll wrote the following:



He doesn't say whether this is an actual clearance received or a
hypothetical scenario. The book phraseology would be, "Cleared to UDUZI,
maintain four thousand until entering the TAA, cleared RNAV runway niner
left approach." If he's already crossed the TAA boundary the clearance
would be just, "Cleared RNAV runway niner left approach."


"Cleared direct UDUZI, maintain 4000' until established, cleared RNAV 9L
approach." sounds like a lot of clearances I have received. Possibly
not by the book verbiage, but real world IMHO.

Why would you read anything into it? I'm not being argumentative; I
just don't understand why you would not "maintain 4000' until
established" and at that point begin to descend. Or, if you didn't like
the profile, get back to ATC and "request lower."

It could be that ATC had crossing traffic at 3000' -- no?
You are established when you enter the TAA.

gman wrote:

don't have to request lower from ATC, clearance for the approach
authorizes me to descend to 2700 at the TAA boundary.



I'm with Mitty on this one. AIM Section 5-4-5.d.4(b) Says:

"Pilots entering the TAA and cleared by air traffic control, are
expected to proceed directly to the IAF associated with that area of
the TAA at the altitude depicted, unless otherwise cleared by air
traffic control."

If the clearance was indeed "...maintain 4000 until established" that
would fit the "..unless otherwise cleared by air traffic control"
clause.

To put this to a test, ask yourself when would you report established
on the approach if asked by ATC to ".. report established on the
approach"? My answer would be when I'm on one of the depicted
portions of the approach and not the TAA.

I guess one could argue that the TAA is a depicted portion of the
approach but I can't find any official publication pointing to that
fact.


The TAAs have published altitudes; i.e., with underscores as opposed to
MSA altitudes, which are not operational.

"bsalai" wrote in message
...

I'm the least expert of anyone in this discussion, but doesn't the box
around the 2700 mean that you should maintain 2700, that they expect you
at that altitude once inside the TAA


I believe you're thinking of a Mandatory Altitude, which is indicated by
both underlining and overlining the altitude figure.

bsalai wrote:

I'm the least expert of anyone in this discussion, but doesn't the box
around the 2700 mean that you should maintain 2700, that they expect you
at that altitude once inside the TAA

Those are MSA's.

"Bee" wrote:

I guess the AIM and the IPH need to state "A TAA straight-in, left base, or
right base area is the regulatory equivalent of a published approach
segment." Otherwise, the uncertainty and sharpshooting is endless. ;-)

Yep. And given the scanty training that controllers receive (or so I have
been told in these groups) WRT RNAV approaches, pilots had best make sure
that they and ATC have the same thing in mind when flying such a clearance.

--
Dan
T-182T at BFM

"Bee" wrote in message
...

I guess the AIM and the IPH need to state "A TAA straight-in, left base,
or right base area is the regulatory equivalent of a published approach
segment." Otherwise, the uncertainty and sharpshooting is endless. ;-)


The AIM already states that, in the Pilot/Controller Glossary:


AREA NAVIGATION (RNAV) APPROACH CONFIGURATION:

a. STANDARD T- An RNAV approach whose design allows direct flight to
any one of three initial approach fixes (IAF) and eliminates the need for
procedure turns. The standard design is to align the procedure on the
extended centerline with the missed approach point (MAP) at the runway
threshold, the final approach fix (FAF), and the initial
approach/intermediate fix (IAF/IF). The other two IAFs will be established
perpendicular to the IF.

b. MODIFIED T- An RNAV approach design for single or multiple runways
where terrain or operational constraints do not allow for the standard T.
The "T" may be modified by increasing or decreasing the angle from the
corner IAF(s) to the IF or by eliminating one or both corner IAFs.

c. STANDARD I- An RNAV approach design for a single runway with both
corner IAFs eliminated. Course reversal or radar vectoring may be required
at busy terminals with multiple runways.

d. TERMINAL ARRIVAL AREA (TAA)- The TAA is controlled airspace
established in conjunction with the Standard or Modified T and I RNAV
approach configurations. In the standard TAA, there are three areas:
straight-in, left base, and right base. The arc boundaries of the three
areas of the TAA are published portions of the approach and allow aircraft
to transition from the en route structure direct to the nearest IAF. TAAs
will also eliminate or reduce feeder routes, departure extensions, and
procedure turns or course reversal.

1. STRAIGHT-IN AREA- A 30NM arc centered on the IF bounded by a
straight line extending through the IF perpendicular to the intermediate
course.

2. LEFT BASE AREA- A 30NM arc centered on the right corner IAF.
The area shares a boundary with the straight-in area except that it extends
out for 30NM from the IAF and is bounded on the other side by a line
extending from the IF through the FAF to the arc.

3. RIGHT BASE AREA- A 30NM arc centered on the left corner IAF.
The area shares a boundary with the straight-in area except that it extends
out for 30NM from the IAF and is bounded on the other side by a line
extending from the IF through the FAF to the arc.

"Steven P. McNicoll" wrote in message
...

"Bee" wrote in message
...

I guess the AIM and the IPH need to state "A TAA straight-in, left base,
or right base area is the regulatory equivalent of a published approach
segment." Otherwise, the uncertainty and sharpshooting is endless. ;-)


The AIM already states that, in the Pilot/Controller Glossary:


AREA NAVIGATION (RNAV) APPROACH CONFIGURATION:

a. STANDARD T- An RNAV approach whose design allows direct flight to
any one of three initial approach fixes (IAF) and eliminates the need for
procedure turns. The standard design is to align the procedure on the
extended centerline with the missed approach point (MAP) at the runway
threshold, the final approach fix (FAF), and the initial
approach/intermediate fix (IAF/IF). The other two IAFs will be established
perpendicular to the IF.

b. MODIFIED T- An RNAV approach design for single or multiple runways
where terrain or operational constraints do not allow for the standard T.
The "T" may be modified by increasing or decreasing the angle from the
corner IAF(s) to the IF or by eliminating one or both corner IAFs.

c. STANDARD I- An RNAV approach design for a single runway with both
corner IAFs eliminated. Course reversal or radar vectoring may be required
at busy terminals with multiple runways.

d. TERMINAL ARRIVAL AREA (TAA)- The TAA is controlled airspace
established in conjunction with the Standard or Modified T and I RNAV
approach configurations. In the standard TAA, there are three areas:
straight-in, left base, and right base. The arc boundaries of the three
areas of the TAA are published portions of the approach and allow aircraft
to transition from the en route structure direct to the nearest IAF. TAAs
will also eliminate or reduce feeder routes, departure extensions, and
procedure turns or course reversal.

1. STRAIGHT-IN AREA- A 30NM arc centered on the IF bounded by a
straight line extending through the IF perpendicular to the intermediate
course.

2. LEFT BASE AREA- A 30NM arc centered on the right corner IAF.
The area shares a boundary with the straight-in area except that it
extends out for 30NM from the IAF and is bounded on the other side by a
line extending from the IF through the FAF to the arc.

3. RIGHT BASE AREA- A 30NM arc centered on the left corner IAF.
The area shares a boundary with the straight-in area except that it
extends out for 30NM from the IAF and is bounded on the other side by a
line extending from the IF through the FAF to the arc.

The Instrument Flying Handbook, dated 2001, also states, "The arc boundaries
of the three areas of the TAA are published portions of the approach and
allow aircraft to transition from the en route structure direct to the
nearest IAF." Apparently pilots are not making an effort to keep current on
procedures.