wrote:

On Sat, 14 Jul 2007 06:30:41 -0700, q wrote:

Mountainous terrain is modeled for percipitious terrain additives.


Mr Q, can you fill us in on what the additives are? For initial,
intermediate, and final segments?

Thanks, Stan

It is a complex forumla contained in the FAA's Instrument Approach
Procedure Automation (IAPA).

The forumla is not part of any public document.

When it triggers an additive, it is typically in the intermediate
segment, and is not all that much. It can all disappear and then some
on a really cold day.