How wide is an NDB approach course?

Sam Spade wrote:
The real issue here is a simplistic flight test standard that is written
in terms of an on-airport VOR or one within 5 or 10 miles of the airport.

Correct. The PTS is the problem.

When you are flying an IAP away from a VOR station and the FAF is 20 to
25 miles out, with the final going out further, you had darn well have
the CDI centered or at least touching the centered doughnot.

Right. Because depending on which VOR check you use, errors of up to 6
degrees are acceptable. The tower is something like 8 degrees off the
FAC. If the needle is centered, it is still OK.

A sharp
CFI who understands all that would not accept PTS minimum performance on
a extreme distance VOR approach.

Right again - but that presumes the CFI understands the TERPS criteria
used to design the approach. Most do not. Nor would they need to, if
the PTS was written in such a way as to match TERPS. But it's not.
This is disfunctional. The PTS should be written in such a way that,
as a very minimum, it would not be possible to meet PTS standards on a
properly designed approach with properly working equipment and still
slam into an obstruction. It's not that hard.

Michael