Do any of you fly into KADS with a Garmin GPSmap 496? I'm getting a
false terrain alert when flying the Rwy 15 ILS and am wondering if
anyone else has this problem. I'm working with Garmin to resolve this,
but so far what they have suggested has not solved the problem.

It might be the calculation used to determine the terrain. All it has is
the distance from the satellite and formulae to determine terrain distance.


Actually the GPS receiver should have terrain (assume in MSL feet) in
the database (unknown accuracy of data). The GPS receiver as part of
its position determination can calculate the aircraft altitude in the
same units and coordinate system and then compare using whatever
method the receiver programmers decided upon.

Ron Lee