What is the difference between a Nautical Mile (NM) and a Statute Mile (SM)?

The distinction between a Nautical Mile and a Statute Mile primarily revolves around their definitions and applications within aviation and maritime contexts. A Nautical Mile is defined as one minute of latitude and is equivalent to approximately 1.15078 Statute Miles. This makes a Nautical Mile longer than a Statute Mile.

In aviation, the Nautical Mile is essential for flight planning and navigation because it directly relates to the Earth's geometry and is used when calculating distances over the Earth's surface. Since aircraft navigate using latitude and longitude, the Nautical Mile provides a consistent and precise distance measurement that aligns with global positioning systems.

In contrast, Statute Miles are used in land-based navigation in the United States and are not suitable for flight planning purposes, especially considering the curvature of the Earth and the requirements of air traffic management. This is why Nautical Miles are the standard in aviation, as they provide an accurate representation of distance that complements navigational instruments and systems.

Hence, the correct choice highlights that Nautical Miles are crucial for flight planning and speed measurement, aligning with the needs of aviators and ensuring accuracy in navigation.