Scott Moore wrote:
You must not rely on a terrain alert alone for navigation. If the terrian
collision alert is heard, this must be verified by one of the following:

1. Sighting of the ground approching at rapid velocity.

2. Tree branches hitting the airplane.

3. Screams of ground based person(s).

4. Wet sensation in undergarmets.

5. White light at end of long corridor.

Any less than three of these indicators could mean the Garmin has
malfunctioned and the terrain alert should be disabled until the unit
can be verified by authorized service personnel.

--Rick