Instrument Rating Checkride Practice Test

What is the Minimum Enroute Altitude (MEA)?

1. The lowest altitude at which an intersection can be determined

2. The lowest published altitude that ensures navigational signal coverage and obstacle clearance

3. The lowest published altitude that must be crossed at certain fixes

4. The minimum altitude providing obstacle clearance over a 25NM sector

The correct answer is: The lowest published altitude that ensures navigational signal coverage and obstacle clearance

The Minimum Enroute Altitude (MEA), as defined in aviation regulations, is primarily concerned with ensuring both navigational signal coverage and obstacle clearance. Specifically, it represents the lowest published altitude that an aircraft can fly along a specific airway or route segment while still receiving adequate navigation signals, which is crucial for safe instrument flight, particularly in cases of poor visibility or adverse weather conditions. Additionally, the MEA guarantees that the aircraft is flying at an altitude above the highest obstacles in the vicinity, thereby reducing the risk of terrain collision. The importance of upholding the MEA cannot be overstated, as it is designed to maintain safety by providing a clear path free from obstacles and ensuring continued navigation signal availability, which is vital for maneuvering through controlled airspace. This definition reflects the balance of safety in terms of altitude and the requirement for navigational aids, which is critical during instrument flying operations.