What is EGPWS and how does it prevent controlled flight into terrain?

EGPWS (Enhanced Ground Proximity Warning System) prevents CFIT (Controlled Flight Into Terrain) accidents by alerting pilots to terrain and obstacle hazards. It uses: GPS position, Terrain/obstacle database, Radio altimeter, and Aircraft configuration data. Functions include: Terrain awareness display showing terrain relative to aircraft, Predictive look-ahead alerting (terrain, obstacles), Standard GPWS modes (excessive descent rate, terrain closure, altitude callouts, glideslope deviation, windshear), and Escape guidance. Alerts progress from caution to warning with increasing urgency. EGPWS (Honeywell) and TAWS (generic term) have dramatically reduced CFIT accidents since introduction. Mandatory for commercial aircraft.