Definition
The lowest published altitude on an airway segment that guarantees both acceptable RNAV (area navigation) signal reception and obstacle clearance over the entire segment when the aircraft is navigating by RNAV. On charts, an RNAV MEA is identified by the suffix 'G' (for GNSS-based RNAV routes) and applies only to aircraft using RNAV for course guidance, rather than to aircraft tracking ground-based navaids on the same airway.
Plain English
The lowest altitude you are allowed to fly along a route segment when you are navigating with RNAV equipment. It keeps you clear of terrain and obstacles and ensures your navigation signals work reliably for that whole segment.
Context Anchor
Seen on IFR en route charts and in instrument procedure discussions for RNAV routes, especially when choosing or checking a legal altitude between fixes.
Derivation
MEA stands for Minimum En Route Altitude. RNAV means Area Navigation — a method that lets the aircraft fly directly between any two points rather than only along ground-based navaids. So an RNAV MEA is the minimum en route altitude that applies specifically when the pilot is using RNAV for navigation.
Why Pilots Care
Ensures terrain and obstacle clearance on RNAV routes while allowing lower altitudes than some conventional MEAs due to precise area navigation.
Intuition Check
“Minimum” does not mean “recommended” or “best.” It means the lowest published altitude that still satisfies the route’s required clearance and navigation requirements.
Example Sentence 1
Because we were equipped and approved for RNAV, we filed the lower RNAV MEA for that segment instead of the conventional MEA.
Example Sentence 2
ATC cleared the flight direct at the RNAV MEA after confirming the aircraft was properly equipped for the route.