SLE LOC BC RWY 13: ARTTY Int NA for FAF

The SLE LOC BC RWY 13 FAF is located at ARTTY:

http://myairplane.com/databases/appr.../SLE_lbr13.pdf

In the notes it says "Artty Int not authorized for final approach fix".
However it sure does look like the FAF in the elevation view. So only
the fan marker can be used to identify the FAF? Why note that it's
5.6 DME off I-SLE? Is this just to prevent people without DME from
identifying it using the radial off of CVO?

--
Ben Jackson

http://www.ben.com/

On Thu, 02 Oct 2003 19:13:40 GMT, (Ben Jackson) wrote:

The SLE LOC BC RWY 13 FAF is located at ARTTY:

http://myairplane.com/databases/appr.../SLE_lbr13.pdf

In the notes it says "Artty Int not authorized for final approach fix".
However it sure does look like the FAF in the elevation view. So only
the fan marker can be used to identify the FAF? Why note that it's
5.6 DME off I-SLE? Is this just to prevent people without DME from
identifying it using the radial off of CVO?

My guess:

Artty is NOT defined with respect to the DME but rather as the intersection
of the CVO 359.08° radial with the I-SLE localizer. My guess is that the
precision of that location does not meet TERP's criteria for an FAF.

But I see no reason from the chart why one could not use the I-SLE
localizer and the I-SLE 5.6 DME to define the FAF.


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

INT means the fix formed by the LOC and the radial from the VOR. That is
because that VOR/LOC INTersection does not meet FAF accuracy requirements.
Either the fan marker or DME must be used to identify the FAF inbound on
final approach.

Ben Jackson wrote:

The SLE LOC BC RWY 13 FAF is located at ARTTY:

http://myairplane.com/databases/appr.../SLE_lbr13.pdf

In the notes it says "Artty Int not authorized for final approach fix".
However it sure does look like the FAF in the elevation view. So only
the fan marker can be used to identify the FAF? Why note that it's
5.6 DME off I-SLE? Is this just to prevent people without DME from
identifying it using the radial off of CVO?

--
Ben Jackson

http://www.ben.com/

Yup. The Corvallis VOR is more than 30 nm away. I don't know the specific requirements for defining a FAF, but 30 nm is the limit for designing an approach using the VOR as the primary navigation source.

Interesting wording in the note, though. I've always thought of the DME figure as an alternate way to locate the intersection, not as a separate DME fix of the same name as the intersection.

It makes sense after you guys explain it, but I would have been confused as well.

wrote:


INT means the fix formed by the LOC and the radial from the VOR. That is
because that VOR/LOC INTersection does not meet FAF accuracy requirements.
Either the fan marker or DME must be used to identify the FAF inbound on
final approach.

Ben Jackson wrote:

The SLE LOC BC RWY 13 FAF is located at ARTTY:

http://myairplane.com/databases/appr.../SLE_lbr13.pdf

In the notes it says "Artty Int not authorized for final approach fix".
However it sure does look like the FAF in the elevation view. So only
the fan marker can be used to identify the FAF? Why note that it's
5.6 DME off I-SLE? Is this just to prevent people without DME from
identifying it using the radial off of CVO?

--
Ben Jackson

http://www.ben.com/

"Fred E. Pate" wrote:

Yup. The Corvallis VOR is more than 30 nm away. I don't know the specific requirements for defining a FAF, but 30 nm is the limit for designing an approach using the VOR as the primary navigation source.

TERPS 287c. FAF. For a fix to be satisfactory for use as a FAF, the fix error should not exceed plus-or-minus 1 mile (see figures 31-1 and 31-2). It may be as large as plus-or-minus 2 miles when:
(1) The MAP is marked by overheading an air navigation facility (except 75 MHz markers); OR
(2) A buffer of equal length to the excessive fix error is provided between the published MAP and the point where the missed approach surface begins (see figure 32).

They work the law of sines on the crossing radial, using plus or minus 3.6 degrees.



Interesting wording in the note, though. I've always thought of the DME figure as an alternate way to locate the intersection, not as a separate DME fix of the same name as the intersection.

It makes sense after you guys explain it, but I would have been confused as well.

It's even more confusing on the Jepp chart because Jepp doesn't use the term "INT." "INT" is a "NACOism," for which I can't find a definition in their legend, although it may be there. The FAA procedures
designers make notes for NACO charts. "INT" means two bearings or radials to them. ;-) Yet, note that TERPS calls it a fix. ;-)

Watch out! THe FAA is changing the localizer only FAF's on ILS's to align with the ILS FAF (ie the glide slope intercept at the intermediate segment altitude) as part of an RNAV standardization initiative.
The result is that the outer markers no longer mark the localizer FAF, and where there is no VOR close enough to provide a crossing radial that meets the criteria the FAF is a DME fix. The result is the
procedure gets marked with "DME required", which means you have to have either DME or an IFR GPS in order to legally fly the approach unless the procedure also permits radar identification of the fix (has to
be marked as such on the procedure chart). The result is if you don't have that equipment, you're not going to be legal to fly approaches at more and more airports. They did it to us at Providence this
summer, and are working their way down to smaller airports. BTW, AOPA has been useless on this, in fact they haven't even returned calls they promised. Anyone who flys aircraft IFR that doesn't have this
equipment should complain to the AOPA as well as to the local flight safety office. The Boston flight saftey office, at least, is tallying the complaints about this to determine the extent of the affected
pilots.

"Fred E. Pate" wrote:

Yup. The Corvallis VOR is more than 30 nm away. I don't know the specific requirements for defining a FAF, but 30 nm is the limit for designing an approach using the VOR as the primary navigation source.

Interesting wording in the note, though. I've always thought of the DME figure as an alternate way to locate the intersection, not as a separate DME fix of the same name as the intersection.

It makes sense after you guys explain it, but I would have been confused as well.

wrote:


INT means the fix formed by the LOC and the radial from the VOR. That is
because that VOR/LOC INTersection does not meet FAF accuracy requirements.
Either the fan marker or DME must be used to identify the FAF inbound on
final approach.

Ben Jackson wrote:

The SLE LOC BC RWY 13 FAF is located at ARTTY:

http://myairplane.com/databases/appr.../SLE_lbr13.pdf

In the notes it says "Artty Int not authorized for final approach fix".
However it sure does look like the FAF in the elevation view. So only
the fan marker can be used to identify the FAF? Why note that it's
5.6 DME off I-SLE? Is this just to prevent people without DME from
identifying it using the radial off of CVO?

--
Ben Jackson

http://www.ben.com/


--
--Ray Andraka, P.E.
President, the Andraka Consulting Group, Inc.
401/884-7930 Fax 401/884-7950
email
http://www.andraka.com

"They that give up essential liberty to obtain a little
temporary safety deserve neither liberty nor safety."
-Benjamin Franklin, 1759

"Fred E. Pate" wrote:

Yup. The Corvallis VOR is more than 30 nm away. I don't know the specific requirements for defining a FAF, but 30 nm is the limit for designing an approach using the VOR as the primary navigation source.

Interesting wording in the note, though. I've always thought of the DME figure as an alternate way to locate the intersection, not as a separate DME fix of the same name as the intersection.

It makes sense after you guys explain it, but I would have been confused as well.


Here is an explanation from a manager at the National Flight Procedures Office:

In the AIM, Pilot/Controller Glossary is:

INTERSECTION-

a. A point defined by any combination of courses, radials, or bearings of
two or more navigational aids.

b. Used to describe the point where two runways, a runway and a taxiway,
or two taxiways cross or meet.

Naturally, the a. definition is what we're referring to, and further the
Notice to Airmen Publication (NTAP) uses "INT" as the abbreviation for