DENIS SMITH wrote:

What you guys are talking about is exactly why CATII
and CATIII approaches require radio altimeters.  On
slope and on course it's the only way you can be sure
of your height above ground.  Even then some airports
have difficulty because of steeply sloped terrain in
the vicinity of the runway threshold.  (Seattle
landing south comes to mind.)

San Diego landing North is pretty exciting too. There is a parking
garage next to the freeway that you clear by about 50-100 feet on a 
four degree glide slope.

Which brings us back to Free Flight software with topographical
information. Burt's idea of synthetic aperture radar and/or
infrared (flir) information would also help greatly.

Paul Lamar

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