What is the clearance provided by Maximum Elevation Figures (MEF)?

Maximum Elevation Figures (MEFs) represent the highest elevation of terrain and obstacles within a specific quadrangle of a chart. They provide a safety margin to ensure that aircraft can safely navigate, especially when flying at lower altitudes.

The correct answer defines the clearance provided by MEFs as being within the range of 100 to 199 feet above the highest point within that quadrangle, which helps account for both the terrain and any potential obstructions. This range is crucial for pilots to maintain safe altitudes, especially during VNAV operations or when flying in areas of high terrain.

By using MEFs, pilots can effectively plan their altitude to navigate safely while maintaining a buffer that helps in avoiding any unexpected obstructions or changes in elevation. This practice is particularly important in mountainous or rugged terrain where the risk of encountering unobserved obstacles is significantly higher.