"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. ;-)