OROCA

AcronymDefinition
OROCAOff Route Obstruction Clearance Altitude
References in periodicals archive ?
So now, in addition to having to look at your OROCA and service volumes when planning off-airway flight, you have to review your position reporting requirements as well, just in case ATC's radar goes on the fritz.
The goal of the departure is to get us safely off an airport and established in the enroute structure where published routes provide obstacle clearance and signal reception, and off-airway routes can be assessed with an understanding of OROCA and navaid service volumes.
You can also descend to the MEA or OROCA as appropriate.
It's vital to make sure that you at least know the minimum off-route altitude (MORA, also called the Off Route Obstruction Clearance Altitude or OROCA in the U.
Thus, a mountain even slightly outside the corner of the quadrant creates a high OROCA, even though the terrain adjacent to the mountain may be low and flat.
Both OROCAs and MEAs must be "ignored" to make mountain IFR possible in a light airplane.
Nor is the OROCA (off-route obstruction clearance altitude)--which you'd be using on a "direct" anywhere near 4000 feet.