EGPWS uses aircraft inputs such as position, attitude, air speed and glideslope, which along with internal terrain, obstacles, and airport databases predict a potential conflict between the aircraft's flight path and terrain or an obstacle.
Update to the latest Terrain Database at least twice a year. Updates can be downloaded from the Database Page of the EGPWS web site.
Use GPS. It's simple, uses accurate WGS-84 data and is independent of FMS and RNAV failures.
Find out more about EGPWS features and download safety examples from the modules below.