What is the difference between the MEA and the MOCA?

The correct answer highlights that the Minimum Enroute Altitude (MEA) serves two primary purposes: ensuring that aircraft have sufficient altitude to clear obstacles and providing adequate navigation signal coverage throughout the route. The MEA guarantees a safe vertical clearance over terrain and obstacles while also ensuring that the aircraft can receive reliable navigation signals from ground stations.

In contrast to the MEA, the Minimum Obstruction Clearance Altitude (MOCA) is primarily focused on providing obstacle clearance but has a limited range concerning navigation signal coverage—it does not guarantee the same level of signal integrity beyond 22 nautical miles from the VOR or navigation facility. Thus, MOCA is primarily intended for terrain clearance and may not always provide navigational signal reliability beyond this distance.

Understanding the distinctions between MEA and MOCA is important for flight planning and safety, as pilots must ensure they are at the appropriate altitudes to navigate effectively while maintaining safe separation from terrain and obstacles.