How Is Oca Calculated

The calculated OCA/H is the height of the highest obstacle, or equivalent missed approach obstacles, plus an aircraft-related allowance. In assessing these obstacles, the operational variables of the aircraft category, approach coupling, category of operation, and missed approach climb performance are considered.

What is an obstacle clearance height defined as?

Obstacle clearance altitude (OCA) or Obstacle clearance height (OCH): The lowest altitude or the lowest height above the elevation of the relevant runway threshold or the aerodrome elevation as applicable used in establishing compliance with appropriate obstacle clearance criteria.

What is MEA and MOCA?

MEA is the altitude that will provide obstacle clearance, as well as ensuring navaid signal coverage for the airway. MOCA is the lowest altitude you can go down to with legal IFR separation. A good example of when MEA and MOCA differ would be flying through mountains.