VOR/DME Approach Question

On Wed, 25 Aug 2004 22:36:41 -0500, J Haggerty
wrote:

then it would be up to ATC to indicate that the course reversal
was not necessary by stating that to the pilot.

By what authority can ATC do this, on this particular approach?

Chip has already indicated that ATC could not issue vectors to final for
this approach; and I am not aware of any authority given ATC to modify
published SIAP's by eliminating required course reversals, absent VTF or
timed approaches.



--ron

I didn't find any written authority that directly authorizes this. It
would be more a compilation of bits and pieces from several regulations.
Unfortunately, there's not much out there in the books that relates
directly to GPS overlay procedures.

Example; FAAH 7110.65 Para 4-8-1 b. "For aircraft operating on
unpublished routes, issue the approach clearance only after the aircraft
is:
3. Established on a heading or **course** that will intercept the
initial segment at the initial approach fix, or intermediate segment at
the intermediate fix when no initial approach fix is published, for a
GPS or RNAV instrument approach procedure at an angle not greater than
90 degrees. Angles greater than 90 degrees may be used when a hold in
lieu of procedure turn pattern is depicted at the fix for the instrument
approach procedure. (See FIG 4-8-2.)"
EXAMPLE- Aircraft 1 can be cleared direct to CENTR. The intercept
angle at that IAF is 90 degrees or less. The minimum altitude for IFR
operations (14 CFR Section 91.177) along the flight path to the IAF is
3,000 feet. "Cleared direct CENTR, maintain at or above three thousand
until CENTR, cleared R-NAV Runway One Eight approach."

In this example, they are talking about RNAV procedures, but the UH-60
was navigating to the IAF using the GPS. If he didn't have GPS, he would
not have been on an unpublished non-radar route to the IAF and this
paragraph would not apply.

On the procedure in question, the only purpose of the "hold in lieu of
PT" is to allow an aircraft on the feeder from HCH to complete a course
reversal so that he can align himself with the final approach course. It
is not used to get a lower altitude and consequent descent gradient as
it might be on some course reversal procedures. The UH-60 was already
aligned within the parameters of the TERPS criteria (90 degrees). If the
route that the UH-60 flew just magically appeared as a published route
on this procedure, it would be required to be published as NoPT.

JPH

Ron Rosenfeld wrote:
On Wed, 25 Aug 2004 22:36:41 -0500, J Haggerty
wrote:


then it would be up to ATC to indicate that the course reversal
was not necessary by stating that to the pilot.


By what authority can ATC do this, on this particular approach?

Chip has already indicated that ATC could not issue vectors to final for
this approach; and I am not aware of any authority given ATC to modify
published SIAP's by eliminating required course reversals, absent VTF or
timed approaches.

On Thu, 26 Aug 2004 18:10:00 -0500, J Haggerty
wrote:

I didn't find any written authority that directly authorizes this. It
would be more a compilation of bits and pieces from several regulations.
Unfortunately, there's not much out there in the books that relates
directly to GPS overlay procedures.

Then I don't understand you making up new rules.


Example; FAAH 7110.65 Para 4-8-1 b. "For aircraft operating on
unpublished routes, issue the approach clearance only after the aircraft
is:
3. Established on a heading or **course** that will intercept the
initial segment at the initial approach fix, or intermediate segment at
the intermediate fix when no initial approach fix is published, for a
GPS or RNAV instrument approach procedure at an angle not greater than
90 degrees. Angles greater than 90 degrees may be used when a hold in
lieu of procedure turn pattern is depicted at the fix for the instrument
approach procedure. (See FIG 4-8-2.)"
EXAMPLE- Aircraft 1 can be cleared direct to CENTR. The intercept
angle at that IAF is 90 degrees or less. The minimum altitude for IFR
operations (14 CFR Section 91.177) along the flight path to the IAF is
3,000 feet. "Cleared direct CENTR, maintain at or above three thousand
until CENTR, cleared R-NAV Runway One Eight approach."

In this example, they are talking about RNAV procedures, but the UH-60
was navigating to the IAF using the GPS. If he didn't have GPS, he would
not have been on an unpublished non-radar route to the IAF and this
paragraph would not apply.

On the procedure in question, the only purpose of the "hold in lieu of
PT" is to allow an aircraft on the feeder from HCH to complete a course
reversal so that he can align himself with the final approach course. It
is not used to get a lower altitude and consequent descent gradient as
it might be on some course reversal procedures. The UH-60 was already
aligned within the parameters of the TERPS criteria (90 degrees). If the
route that the UH-60 flew just magically appeared as a published route
on this procedure, it would be required to be published as NoPT.

I think what you are proposing is potentially dangerous. The fact of the
matter is that there is no published route. There also is no TAA.

Are we supposed to believe that ATC is now able to apply all of the
appropriate TERPS criteria "on the fly" in off route areas, and also have
the authority to legally and safely allow pilots to circumvent the
published regulations and SIAP?

I think that more than a compilation of bits and pieces from several
regulations is required to justify this conclusion.

Not all obstacles are on our charts. At my local airport, the controlling
obstacle for the GPS and/or NDB 15 approach appears on no aviation charts
at all.

It may be that a TAA could be established around MINES, and then this
discussion would be moot. But with a TAA, we pilots know that the area has
been surveyed.

It may also be that local pilots who are familiar with the area can safely
(although not legally, in my opinion) circumvent the published approach.

I just don't think you have shown that ATC has the authority to make that
circumvention legal. And I don't buy the "bits and pieces".


--ron

Ron,
If you read the paragraph, you'll note that the requirement is that the
aircraft be on a route or vector to an IAF. It's not unusual for an
aircraft to be cleared direct to a fix even though there's not a
published route. ATC would be required to ensure the aircraft was at a
suitable altitude for IFR operations on this route, but the navigation
would be provided by the pilot, in this case using GPS.
The paragraph I quoted actually gives the authority for ATC to give an
approach clearance by clearing him direct to MINES at 5000. If the
intercept angle was greater than 90 degrees, then a hold-in-lieu of PT
would have to be published, and on this procedure there is one
published, but it's not needed in the example because a course reversal
is not needed. Note that we're talking about a holding pattern in lieu
of a PT, and not an actual PT. An aircraft flying the VOR from the
feeder fix would be required to complete the hold-in-lieu for course
reversal.
Stand-alone RNAV procedures are published either with a TAA or without a
TAA. If there was a TAA, then the controller would not have to provide
the 5000 altitude restriction if the aircraft was within the TAA area,
because he would be on a published portion of the approach and could use
Para 4-8-1 b subpara 1 and 2 as directed by 4-8-1 e instead of 4-8 b
subpara 3. The situation I'm talking about is using subpara 3. The
aircraft was using a route rather than vectors, so the rules regarding
vectors do not apply.

Ron Rosenfeld wrote:



Then I don't understand you making up new rules.

I didn't make up para 4-8-1 b.

Example; FAAH 7110.65 Para 4-8-1 b. "For aircraft operating on
unpublished routes, issue the approach clearance only after the aircraft
is:
3. Established on a heading or **course** that will intercept the
initial segment at the initial approach fix, or intermediate segment at
the intermediate fix when no initial approach fix is published, for a
GPS or RNAV instrument approach procedure at an angle not greater than
90 degrees. Angles greater than 90 degrees may be used when a hold in
lieu of procedure turn pattern is depicted at the fix for the instrument
approach procedure. (See FIG 4-8-2.)"
EXAMPLE- Aircraft 1 can be cleared direct to CENTR. The intercept
angle at that IAF is 90 degrees or less. The minimum altitude for IFR
operations (14 CFR Section 91.177) along the flight path to the IAF is
3,000 feet. "Cleared direct CENTR, maintain at or above three thousand
until CENTR, cleared R-NAV Runway One Eight approach."

In this example, they are talking about RNAV procedures, but the UH-60
was navigating to the IAF using the GPS. If he didn't have GPS, he would
not have been on an unpublished non-radar route to the IAF and this
paragraph would not apply.

On the procedure in question, the only purpose of the "hold in lieu of
PT" is to allow an aircraft on the feeder from HCH to complete a course
reversal so that he can align himself with the final approach course. It
is not used to get a lower altitude and consequent descent gradient as
it might be on some course reversal procedures. The UH-60 was already
aligned within the parameters of the TERPS criteria (90 degrees). If the
route that the UH-60 flew just magically appeared as a published route
on this procedure, it would be required to be published as NoPT.


I think what you are proposing is potentially dangerous. The fact of the
matter is that there is no published route. There also is no TAA.

The paragraph is talking about **unpublished** routes. TAA's use a
different paragraph of the 7110.65.

Are we supposed to believe that ATC is now able to apply all of the
appropriate TERPS criteria "on the fly" in off route areas, and also have
the authority to legally and safely allow pilots to circumvent the
published regulations and SIAP?
No, they use the criteria contained in the paragraph shown.


I think that more than a compilation of bits and pieces from several
regulations is required to justify this conclusion.

Not all obstacles are on our charts. At my local airport, the controlling
obstacle for the GPS and/or NDB 15 approach appears on no aviation charts
at all.

True, but TRACONS and CENTERS have to have their charts approved by AVN
and they have to ensure the same IFR altitudes as the feeder routes and
TAA's. The TAA's and feeder routes don't normally depict obstacles either.

It may be that a TAA could be established around MINES, and then this
discussion would be moot. But with a TAA, we pilots know that the area has
been surveyed.
Overlay procedures do not have TAA's. The GPS portion is treated just as
the paragraph above explains.


--ron

JPH

J Haggerty wrote:

aligned within the parameters of the TERPS criteria (90 degrees). If the
route that the UH-60 flew just magically appeared as a published route
on this procedure, it would be required to be published as NoPT.

Not necessarily. Intercept angle is one of two criterion for publishing "NoPT."
The other is descent gradient.

The route flown by the UH-60 was using Center's IFR altitude at 5000.
Descent gradient was not a problem, as the IAF altitude was also 5000.

wrote:

aligned within the parameters of the TERPS criteria (90 degrees). If the
route that the UH-60 flew just magically appeared as a published route
on this procedure, it would be required to be published as NoPT.


Not necessarily. Intercept angle is one of two criterion for publishing "NoPT."
The other is descent gradient.

"J Haggerty" wrote in message
news:65uXc.61810$wo.23863@okepread06...
I didn't find any written authority that directly authorizes this. It
would be more a compilation of bits and pieces from several regulations.
Unfortunately, there's not much out there in the books that relates
directly to GPS overlay procedures.

I agree the books are spotty for GPS overlay procedures.



Example; FAAH 7110.65 Para 4-8-1 b. "For aircraft operating on
unpublished routes, issue the approach clearance only after the aircraft
is:
[snipped]

On the procedure in question, the only purpose of the "hold in lieu of
PT" is to allow an aircraft on the feeder from HCH to complete a course
reversal so that he can align himself with the final approach course. It
is not used to get a lower altitude and consequent descent gradient as
it might be on some course reversal procedures. The UH-60 was already
aligned within the parameters of the TERPS criteria (90 degrees). If the
route that the UH-60 flew just magically appeared as a published route
on this procedure, it would be required to be published as NoPT.

Good points. However, FAAO 7110.65, paragraph 5-9-1 is the controlling
paragraph relating to radar vectors to FAC for Center controllers. 5-9-1d
says:

"d. EN ROUTE. The following provisions are required before an aircraft may
be vectored to the final approach course:

1. The approach gate and a line (solid or broken), depicting the final
approach course starting at or passing through the approach gate and
extending away from the airport, be displayed on the radar scope; for a
precision approach, the line length shall extend at least the maximum range
of the localizer; for a nonprecision approach, the line length shall extend
at least 10NM outside the approach gate; and

2. The maximum range selected on the radar display is 150 NM; or

3. An adjacent radar display is set at 125 NM or less, configured for the
approach in use, and is utilized for the vector to the final approach
course.

4. If unable to comply with subparas 1, 2, or 3 above, issue the clearance
in accordance with para 4-8-1 Approach Clearance."



In the case of every non-precision approach in my airspace, including RKW,
the FAC is not displayed on the radar scope. We fail the test at provision
#1. The weenie language that applies to this particular approach into RKW
clearly forbids the controller from vectoring to FAC. Even if the pilot can
fly this approach without the course reversal, it looks like Center ATC
can't clear him to do so. Too bad those DME arc's disappeared...

Thanks for the input, I've learned a lot.



Chip, ZTL