How should distance be communicated in aviation radio transmissions?

In aviation radio transmissions, distance is communicated in nautical miles. This is the standard practice because nautical miles are specifically designed to relate to the Earth's geometry, which is essential in navigation. One nautical mile equals one minute of arc and correlates directly with the Earth's latitude and longitude, making it particularly useful for navigation over long distances, especially across water or in the context of airspace management.

By using nautical miles, pilots and air traffic controllers can more effectively communicate and coordinate positions and distances, allowing for safer flight operations. The use of this measurement helps maintain uniformity in international aviation, as nautical miles are recognized globally.

In contrast, the other units such as kilometers, statute miles, and meters do not serve this purpose in aviation. Kilometers and meters can create confusion since they are more commonly used for land measurements and do not relate to the navigation system's celestial context. Statute miles are not standardized in aviation, which can lead to misinterpretation and errors in distance reporting and navigation.