Definition
An altitude shown on certain charts that provides terrain and obstacle clearance within a defined area off the published airway or route. A MORA is computed to give 1,000 feet of clearance over terrain and obstructions up to 6,000 feet, and 2,000 feet of clearance in areas where terrain or obstacles exceed 6,000 feet. It applies to a strip on either side of a route (Route MORA) or to a grid square on the chart (Grid MORA).
Plain English
The lowest altitude that is safe to fly over the ground and any tall things on it, in an area that isn't directly on the published route. It gives you a built-in buffer above the highest terrain or obstacle in that area.
Context Anchor
Seen on some instrument and en route charting products when planning or checking IFR altitudes away from a published airway or route.
Derivation
"Off-route" signals that this altitude is for places away from the charted airway, and "minimum" means it is the floor — the lowest you should be — not a target altitude.
Why Pilots Care
It supplies a reliable altitude floor for off-route navigation, reducing the risk of controlled flight into terrain during deviations or direct routing.
Grounding Statement
Think of MORA as an obstacle-clearance floor for off-route planning, not as a complete guarantee that the altitude is suitable for every IFR need.
Intuition Check
Do not read “minimum” as “the altitude I should automatically fly.” Here it means the lowest charted altitude intended to provide obstacle clearance for the off-route area or segment.
Example Sentence 1
After being vectored off the airway for traffic, the crew checked the Grid MORA on the chart to confirm they were safely above the terrain.
Example Sentence 2
When weather forced a deviation from the airway, the crew climbed to the sector MORA.