OLV GPS 36 approach question

Allen:

When I orginally read your post, I pictured you making a right base
entry to the procedure, even though you mentioned DOCAP. Anyway, my
reply was based on this incorrect mental image.

The published intermediate segment after DOCAP has a published altitude
of 2,100, so the controller's instruction was appropriate. The
published altitude prior to that fix is for the holding pattern course
reversal, which you were not required to perform coming from the
straight-in area.

Sorry for the confusion.

wrote in news:1155147361.341080.40380
@p79g2000cwp.googlegroups.com:

The published intermediate segment after DOCAP has a published altitude
of 2,100, so the controller's instruction was appropriate. The
published altitude prior to that fix is for the holding pattern course
reversal, which you were not required to perform coming from the
straight-in area.

Hi Greg,

Bear with me as I am really trying to understand this....

Looking at the FAA version of the approach plate, profile section, it has
2800 to DOCAP, then descend to 2100 at CICAL for the final approach into
OLV.

Based on what you are saying, since I am pretty much a straight in approach
that it's allowable to be cleared by ATC below the profile altitude of 2800
10 miles BEFORE DOCAPS?

10 miles outside DOCAPS, my instructions were descend and maintain 2100,
cleared for the GPS 36.

Allen

A Lieberma wrote:


Bear with me as I am really trying to understand this....

Looking at the FAA version of the approach plate, profile section, it has
2800 to DOCAP, then descend to 2100 at CICAL for the final approach into
OLV.

Based on what you are saying, since I am pretty much a straight in approach
that it's allowable to be cleared by ATC below the profile altitude of 2800
10 miles BEFORE DOCAPS?

10 miles outside DOCAPS, my instructions were descend and maintain 2100,
cleared for the GPS 36.

Allen

Think in terms of being vectored to the final approach course on an ILS.
When done correctly, the controller will vector you at an altitude
below the G/S.

If this approach were an ILS and the controller was setting you up to
intercept the "final" perhaps 3 miles prior to CICAL on a 30 degree
intercept angle. The controller would almost certainly descend you to
2,100 to intercept. He might have you at 2,100 10 miles prior to intercept.

Do you see any difference with your handling, albeit with a new ATC/AIM
procedure?

Looking at the FAA version of the approach plate, profile section, it
has
2800 to DOCAP, then descend to 2100 at CICAL for the final approach
into
OLV.

The 2,800 ft segment you see is the Hold-in-Lieu. A HIL is part of the
initial segment, which doesn't begin until the IAF. From your
direction of flight, the HIL wasn't required for you, so its altitude
didn't apply.

Regardless, ATC has a right to assign you an altitude to maintain until
you arrive at a certain fix; only AFTER you arrive there do published
altitudes apply. Until then, you're relying on their MVA to keep you
safe.

If they had cleared you to ECILE, and told you to maintain 2,100, then
there would have been a problem. You're fine until you get to ECILE,
but the moment you pass that fix, you're in violation of 91.177.

Same thing if you had come from the north direction to DOCAP. You'd be
fine at 2,100 until the fix, but the HIL is required from this
direction and you'd be in violation of 91.177 once you started the hold
entry.


Sam: The fix DOCAP is labeld IF/IAF. Does the segment from DOCAP to
CICAL use initial or intermediate ROC ?

wrote:
Looking at the FAA version of the approach plate, profile section, it
has
2800 to DOCAP, then descend to 2100 at CICAL for the final approach
into
OLV.

The 2,800 ft segment you see is the Hold-in-Lieu. A HIL is part of the
initial segment, which doesn't begin until the IAF. From your
direction of flight, the HIL wasn't required for you, so its altitude
didn't apply.

Regardless, ATC has a right to assign you an altitude to maintain until
you arrive at a certain fix; only AFTER you arrive there do published
altitudes apply. Until then, you're relying on their MVA to keep you
safe.

If they had cleared you to ECILE, and told you to maintain 2,100, then
there would have been a problem. You're fine until you get to ECILE,
but the moment you pass that fix, you're in violation of 91.177.

Same thing if you had come from the north direction to DOCAP. You'd be
fine at 2,100 until the fix, but the HIL is required from this
direction and you'd be in violation of 91.177 once you started the hold
entry.


It seems to me you are ignoring the depiction of the southern sector on
the map view that shows 2800. This applies to aircraft inbound to
DOCAP from anywhere southern. Why are you saying that it does not
apply? (I.e. why is the controller allowed to clear the a/c to DOCAP
and descend to 2100?).
--
Thanks,
John Clonts
Temple, Texas

John Clonts wrote:

wrote:


It seems to me you are ignoring the depiction of the southern sector on
the map view that shows 2800. This applies to aircraft inbound to
DOCAP from anywhere southern. Why are you saying that it does not
apply? (I.e. why is the controller allowed to clear the a/c to DOCAP
and descend to 2100?).

2,100 applies at DOCAP per the IAP. The MVA is 2,000 to the west of
DOCAP and 2,100 to the east.

Again, a more consistent handling with the IAP profile and human-factors
would have been for ATC to assign 2,800 to DOCAP.

Sam Spade wrote:
John Clonts wrote:

wrote:


It seems to me you are ignoring the depiction of the southern sector on
the map view that shows 2800. This applies to aircraft inbound to
DOCAP from anywhere southern. Why are you saying that it does not
apply? (I.e. why is the controller allowed to clear the a/c to DOCAP
and descend to 2100?).

2,100 applies at DOCAP per the IAP. The MVA is 2,000 to the west of
DOCAP and 2,100 to the east.

Yes but I am talking about *prior to* DOCAP. 2800 applies prior to
DOCAP per the IAP. If ATC clears an a/c to 2100 prior to DOCAP is it
(1) a controller error which should be refused by the pilot, or (2) ok
because somehow "mva trumps iap arrival sector altitude"?

Again, a more consistent handling with the IAP profile and human-factors
would have been for ATC to assign 2,800 to DOCAP.

John Clonts wrote:
Sam Spade wrote:

John Clonts wrote:


wrote:


It seems to me you are ignoring the depiction of the southern sector on
the map view that shows 2800. This applies to aircraft inbound to
DOCAP from anywhere southern. Why are you saying that it does not
apply? (I.e. why is the controller allowed to clear the a/c to DOCAP
and descend to 2100?).

2,100 applies at DOCAP per the IAP. The MVA is 2,000 to the west of
DOCAP and 2,100 to the east.


Yes but I am talking about *prior to* DOCAP. 2800 applies prior to
DOCAP per the IAP. If ATC clears an a/c to 2100 prior to DOCAP is it
(1) a controller error which should be refused by the pilot, or (2) ok
because somehow "mva trumps iap arrival sector altitude"?


Again, a more consistent handling with the IAP profile and human-factors
would have been for ATC to assign 2,800 to DOCAP.


Under the present wording in the ATC Handbook MVA trumps the
direct-entry sector's altitude.

Another way to look at it is the IAP begins at the IF based on the
clearance.

An anology would be a "true" vector to final, say a 30 degree cut to the
approach course 2 miles inside DOCAP. 2,100 would be an acceptable
controller assignment in that case.

The new application might work better with a restriction to not assign
an altitude below the IF crossing altitude. But, that is not how it
reads at present.

It seems to me you are ignoring the depiction of the southern sector
on
the map view that shows 2800. This applies to aircraft inbound to
DOCAP from anywhere southern.

That sector is essentially a feeder route. If cleared for the approach
within that area, you could descend down to 2,800 if you were above it,
absent any other altitude assignment by ATC.

Many approaches have feeder routes, but you're not obligated to fly
them to the IAF if ATC clears you direct to the IAF and assigns an
altitude.

wrote:
Looking at the FAA version of the approach plate, profile section, it
has
2800 to DOCAP, then descend to 2100 at CICAL for the final approach
into
OLV.

The 2,800 ft segment you see is the Hold-in-Lieu. A HIL is part of the
initial segment, which doesn't begin until the IAF. From your
direction of flight, the HIL wasn't required for you, so its altitude
didn't apply.

Regardless, ATC has a right to assign you an altitude to maintain until
you arrive at a certain fix; only AFTER you arrive there do published
altitudes apply. Until then, you're relying on their MVA to keep you
safe.

ATC has an obligation to assign an offroute altitude. If they don't
then the pilot has a regulatory obligation to challenge the lack of an
altitude assignment (one of the many changes provided by TWA 514
crashing into Mt. Weather on Dec 1, 1974.)

In this instance it would have been reasonable for the pilot to
challenge the 2,100-foot assignment since 2,800 is shown at DOCAP.

When this change to the AIM and ATC Order was discussed, I think
everyone envisioned 2,800 being assigned for a direct-to DOCAP. But,
once the real-world takes over...

The controllers really have to know the IAP to assign any altitude less
than that shown in the profile at the IF. I am not sure that is the
conservative way to go, but it is certainly legal so long as there isn't
a step-down in the intermediate somewhere that is missed.


If they had cleared you to ECILE, and told you to maintain 2,100, then
there would have been a problem. You're fine until you get to ECILE,
but the moment you pass that fix, you're in violation of 91.177.

Same thing if you had come from the north direction to DOCAP. You'd be
fine at 2,100 until the fix, but the HIL is required from this
direction and you'd be in violation of 91.177 once you started the hold
entry.


Sam: The fix DOCAP is labeld IF/IAF. Does the segment from DOCAP to
CICAL use initial or intermediate ROC ?

That is the intermediate segment with 500-foot ROC requirements. But,
at a location like this, airspace and descent gradient requirements are
limiting, not ROC. There is probably at least 1,200 feet or more, of
ROC in this particular intermediate segment. The MVA overlying this
intermediate segment is 2,000 feet.