The localizer signal is useable and accurate out to a range of ___ NM from the antenna

The localizer signal is useable and accurate out to a range of ___ NM from the antenna

• A. 18 NM
• B. 15 NM
• C. 10 NM
• D. 25 NM

Answer: (A)

The localizer provides horizontal guidance to the runway centerline using a VHF signal, and it is designed to be reliable out to about 18 nautical miles from the antenna. Within this range you receive a stable course deviation indication that lets you stay aligned with the runway as you approach. Beyond roughly 18 NM, the signal weakens and the accuracy of the course indication degrades, so you should not rely on it for precise guidance. For comparison, the glide slope (vertical guidance) has a shorter usable range, about 10 NM.

The localizer provides horizontal guidance to the runway centerline using a VHF signal, and it is designed to be reliable out to about 18 nautical miles from the antenna. Within this range you receive a stable course deviation indication that lets you stay aligned with the runway as you approach. Beyond roughly 18 NM, the signal weakens and the accuracy of the course indication degrades, so you should not rely on it for precise guidance. For comparison, the glide slope (vertical guidance) has a shorter usable range, about 10 NM.