What is measured to ensure navigation reception along the entire route when using MEA?

When using Minimum Enroute Altitudes (MEA), the primary focus is on ensuring that an aircraft maintains a safe altitude while providing adequate obstacle clearance during navigation. MEA specifically guarantees that the aircraft will be above any obstacles in the vicinity of the route, thus ensuring safe navigation throughout the entire journey.

The MEA establishes the lowest altitude that can be used in the navigation environment while still maintaining a buffer above terrain and obstacles. This is crucial for avoiding collisions and ensuring that the aircraft is in a safe position relative to any topographical features. By adhering to the MEA, pilots can have confidence that they are navigating safely, hence taking into account altitude and obstacle clearance is essential for any flight planning and execution.

In contrast, factors such as visibility requirements, time for the approach, and overall weather conditions along the route, while important for flight safety, do not directly relate to the fundamental purpose of MEA, which is specifically about altitude management and obstacle avoidance during flight.