What is the coverage extent of a glideslope signal?

The coverage extent of a glideslope signal is essential for ensuring safe and precise approaches during landing. In this case, a glideslope signal typically provides vertical guidance to aircraft as they descend towards the runway.

The correct answer indicates that the glideslope signal coverage is 8° of the localiser centerline, extending out to a distance of 10 nautical miles (nm). This coverage is critical because it defines the area within which an aircraft can receive precise altitude guidance while approaching the runway, ensuring that pilots can maintain proper descent paths and approach angles.

The specification of 8° over a distance of 10 nm aligns with standard aviation practices and regulations, which define the typical operational limits for glideslopes in most commercial airports. This ensures that aircraft can receive a stable and reliable signal throughout the final approach phase, allowing for safer landing operations.

The other options provided do not correctly represent the standardized coverage of a glideslope signal within the aviation industry, emphasizing the importance of understanding these specific measurements for safe aircraft operations.