What is the typical service volume distance for a glideslope?

The typical service volume distance for a glideslope is indeed 10 nautical miles. This distance is crucial as it defines how far from the runway a glideslope system is effective in providing vertical guidance to aircraft during the approach phase of flight. The glideslope is part of the Instrument Landing System (ILS) and typically operates within this range to ensure that pilots receive reliable altitude information while descending toward the runway.

The 10 nautical mile service volume is designed to give pilots adequate time and distance to adjust their descent profile as they approach the threshold, ensuring a safe and controlled approach. This service volume allows for various altitude guidance, which is essential in low visibility scenarios, thereby enhancing safety during landings.

Other options such as 5, 15, or 20 nautical miles are either not aligned with standard glideslope operation or exceed typical operational parameters. While some other systems or procedures may have different ranges, the glideslope's effective distance remains at 10 nautical miles in an ILS setup.