What is the Off Route Obstruction Clearance Altitude (OROCA) used for?

The Off Route Obstruction Clearance Altitude (OROCA) is primarily used to ensure terrain clearance along routes that are not directly following airways. It provides pilots with a guaranteed vertical clearance above obstacles, including terrain and man-made structures, while flying in uncontrolled airspace or when navigating outside established routes. This altitude is calculated to enhance safety by providing a buffer above the maximum elevation of the highest obstruction along the route.

By using OROCA, pilots can navigate with greater confidence, knowing they have appropriate altitude clearance even when they are not following standard air traffic control routes. This is particularly important in mountainous areas or regions where obstacles may be less defined or marked. The other choices focus on different aspects of navigation or emergency procedures that do not align with the specific purpose of OROCA, which centers solely on maintaining safe altitudes above potential obstacles.