Definition
The lowest published altitude between two navigation fixes on a federal airway, off-airway route, or route segment that ensures acceptable navigation signal coverage and meets obstacle clearance requirements between those fixes.
Plain English
On an IFR route, the MEA is the lowest altitude you are allowed to fly that still keeps you safely above terrain and obstacles and within reliable range of the navigation signals you need to follow the route.
Context Anchor
Seen on IFR en route charts and during route planning when choosing or accepting an altitude for a published route segment.
Derivation
Minimum means the lowest allowed amount. En route comes from French and means “on the way” or “along the route.” Together, the phrase points to the lowest allowed altitude while flying along that published IFR route segment.
Why Pilots Care
Flying below the MEA risks losing navigation signals or colliding with terrain; it is the minimum legal altitude for IFR operations on that segment.
Grounding Statement
For a charted IFR route segment, the MEA is the altitude floor where the chart’s promised protection begins.
Intuition Check
Minimum does not mean the best or normal altitude to fly; it means the lowest published altitude that still provides the required protection for that segment. En route does not mean anywhere during the trip; here it applies to a specific published route segment.
Example Sentence 1
The MEA on the next segment of V23 is 7,000 feet, so we'll need to climb before crossing the fix.
Example Sentence 2
Because the MEA was higher than the MOCA, we stayed at or above 5000 feet to ensure navigation signal coverage.