What is the purpose of the Glideslope in an ILS approach?

• A. Provides vertical guidance to aircraft on the final approach.
• B. Provides lateral guidance on the initial approach.
• C. Monitors airspeed and altitude.
• D. Provides range information.

Answer: (A)

Vertical guidance on the final approach is provided by the Glideslope. It defines a glide path, usually about a 3-degree descent, and tells the aircraft whether its descent is too high or too low along that path. The Glideslope transmitter and the aircraft’s ILS receiver generate deviation information that the pilot interprets on the glide slope indicator, helping you stay on the proper vertical path from intercept down to the runway. It does not provide lateral guidance—that comes from the Localizer—the same system also does not give range information or monitor airspeed. So the purpose is to guide descent along the final approach to land.