Minimum Off Route Altitude
There are two types of Minimum Off Route Altitudes (MORAs) – one is called a route MORA and the other is the grid MORA.
MORA's give at least 1,000 feet altitude clearance above terrain, and 2,000 feet in mountainous (an area of changing terrain were the changes of terrain elevation exceed 3000 feet within a distance of 10NM) terrain.
Route MORAs provided an obstacle clearance within 10 nautical miles (19 km) on both sides of the airways and within a 10-nautical-mile (19 km) radius around the ends of the airways.
Grid MORAs provide an obstacle clearance altitude within a latitude and longitude grid block, usually of one degree by one degree. They are presented in feet (ft), omitting the last two figures. Example: 7,600 feet is given as 76.
Grid MORA values clear all terrain and obstructions by 1000 feet in areas where the highest elevations are 5000 feet MSL or lower. MORA values clear all terrain by 2000 feet in areas where the highest elevations are 5001 feet MSL or higher.