Glideslope

Glideslope (or Glide Path) is the vertical guidance component of an ILS, providing the aircraft with the correct descent angle (typically 3 degrees) toward the runway touchdown zone. The glideslope transmitter is located beside the runway, approximately 300 meters from the threshold.

The glideslope operates on UHF frequencies (329.15-335.00 MHz), automatically paired with the localizer frequency. Pilots fly the approach by keeping the glideslope indicator centered, with fly-up/fly-down commands. False glideslope signals can exist at multiples of the correct angle, so proper intercept from below is essential.