What does "Minimum Enroute Altitude (MEA)" refer to?

The concept of Minimum Enroute Altitude (MEA) is critical for pilots navigating through controlled airspace. MEA refers to the lowest altitude that can be flown between two radio navigational fixes while still providing adequate obstacle clearance and ensuring reliable navigational signals. This altitude is designed to keep aircraft safely above terrain and any other obstacles in the area, while also ensuring that pilots maintain adequate radio coverage for navigation.

When a pilot adheres to the MEA, they are assured that they are flying at a safe level with respect to obstacles, along with having reliable signal reception from navigation aids, which is crucial for maintaining proper course. In essence, the MEA ensures both safety and effective navigation during enroute flights.

The other options do not accurately describe the MEA and relate to different aspects of flight or airspace regulation. Understanding the specific purpose and application of MEA is essential for ensuring safe flight operations in controlled airspace.