Glideslope

The constant angle of descent technique requires pilots to maintain a predetermined constant angle and constant rate of descent, which is generally calculated to be about 3°, except when terrain or an obstacle necessitates a steeper descent. When a ground-based glideslope signal is absent, pilots can fly the constant angle of descent approach by using flight management system (FMS) and GPS equipment for electronic guidance.

Staying on the glideslope is vitally important for a safe, stabilized approach and landing.