Definition
An MEA step is the point along an airway or route where the Minimum En Route Altitude changes from one value to another, requiring the pilot to climb or descend to the new MEA before continuing along the route segment.
Plain English
It's the spot on a route where the lowest legal altitude changes, so the pilot has to climb (or descend) to the new minimum before going further.
Context Anchor
Seen on IFR en route charts and in discussions of route segments where navigation signal coverage or obstacle clearance requires a different minimum altitude.
Derivation
MEA stands for Minimum En Route Altitude. 'Step' is used in the everyday sense of a level change — like a step on a staircase — because the altitude requirement steps up or down at that point on the route.
Why Pilots Care
Failing to climb at an MEA step can result in loss of navigation signal or inadequate obstacle clearance.
Analogy
Think of the route altitude like stairs. At an MEA step, the required minimum altitude moves to the next stair up or down; you cannot treat both sides of the step as having the same minimum.
Intuition Check
Do not read step as just a small change. In this context, an MEA step is a required published altitude change at a specific point on the route.
Example Sentence 1
The MEA step at the next fix takes us from 6,000 to 8,000, so we need to start the climb in time to be level by then.
Example Sentence 2
Review the chart for any MEA steps when planning the descent into the destination airport.