Ron Rosenfeld wrote:

On Sat, 07 Feb 2004 05:31:48 -0800, wrote:

There are some approaches where the straight-in minimums step-up for each
higher approach category because of a turning missed approach obstacle issue
that affects the higher turning radii more than the lower.

Are you certain that is the reason for the higher minima? Could you give
an example of an approach where you believe that to be the case?

Medford, Oregon, ILS Runway 14. Note the turning missed approach and a higher
DA/H for each higher approach category.



I am questioning it because I have also seen straight-in minimum visibility
step-up for higher approach category a/c where the missed approach is NOT a
turning one. So clearly, at those approaches, turn radius is not an issue.
An example of this would be the LOC29 approach at KPWM.

Visibility minimums are based on Approach Category and the geometric relationship
of the height of the MDA or DA/H. It is not directly related to any turning
missed approach issue.



Also, well -- I don't know if you use Jepp charts or NOS charts. But on my
Jepp charts, the minima for straight in approaches is subdivided by
aircraft category. The minima for circle-to-land approaches is subdivided
by speed in knots. To me this suggests that the maneuvering speed is
important only in the circle-to-land approach, and not in the straight-in
approach.

The information in the AIM, and in the FAA Instrument Flying Handbook, and
an FAA inspector with whom I used to fly from time to time, all have
indicated to me that the increased category minima for increased a/c
maneuvering speeds only apply to circling approaches, at least for TERPS'd
approaches.

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