"Ron Gordon" wrote in message
et...
Garmin have pointed out how I can read the terrain data from the 496. On
the Terrain page use the cursor to point to a location. The elevation MSL
is shown on line two in the black band above the map.

The south end of runway 15 has a terrain elevation of 715 ft msl in the
database. In fact, it has an actual elevation of only 639 ft msl using the
Jeppesen chart for the airport.

In addition, the terrain just north of the airport is also shown as 715 ft
msl. Using the GPS I've gotten readings that this terrain is actually more
like 650 ft msl.

That may be part of this problem.

That 80' difference could be the culprit but I don't know what the
formula(s) is for triggering a "pull-up" alert. I guess they would have to
program *some* value as a cutoff and maybe that 80' exceed that threshhold.

Have you told them about your observation and if so, are they willing to
tweek the database? If I was Garmin, I'd tweek it and give you a test
database to test out.

Marco