When is it acceptable to fly below the MEA?

The minimum en route altitude (MEA) is established for IFR operations to ensure adequate terrain clearance and reliable navigational signal reception. When flying under IFR, adhering to the MEA is crucial because it provides a safe margin above obstacles and guarantees the reliability of navigation aids in a given area.

Flying below the MEA in IFR conditions exposes the aircraft to potential risks such as terrain and obstacle collisions, and compromise of navigational signal integrity, which can lead to disorientation or loss of aircraft control. Therefore, it's essential to strictly adhere to the MEA during IFR, as doing otherwise is not just unsafe but against regulatory requirements.

In VFR operations, pilots must maintain visual references, and while they may operate below the MEA, IFR pilots do not have that same flexibility. Following a prescribed route doesn't give IFR pilots the authorization to drop below the MEA unless specifically permitted by air traffic control. ATC clearance is required to operate below the MEA only in specific circumstances, such as when given explicit instructions during an approach or maneuver under certain conditions. However, as a general rule, it is never acceptable to fly below the MEA during IFR operations, ensuring safety and compliance with regulations.