Minimum En Route Altitude (MEA)
Minimum En Route Altitude (MEA) is the lowest published altitude for an IFR route segment that provides acceptable navigation signal coverage and meets obstacle clearance requirements. The MEA ensures both terrain/obstacle clearance AND VOR navigation signal coverage along the route.
MEA vs. MOCA
- MEA: Guarantees obstacle clearance AND VOR nav signal reception along the entire segment
- MOCA (Minimum Obstruction Clearance Altitude): Guarantees obstacle clearance, but VOR reception is guaranteed only within 22 NM of the VOR
Operating Below MEA
IFR aircraft must not operate below MEA unless specific conditions permit (e.g., approved for a different minimum, or on an approach below the relevant minimum). Climbing to MEA is not optional — it is the minimum safe altitude for the route.
Cold Temperature Corrections
Cold temperatures can cause the aircraft to fly lower than indicated, making the published MEA potentially insufficient. Cold temperature corrections must be applied to MEA at Canadian airports when temperatures are below −15°C (same as for approach minimums).