Which statement correctly defines DA, MDA, and OCA?

Which statement correctly defines DA, MDA, and OCA?

• A. DA is the decision altitude on precision approaches; MDA is the minimum descent altitude on non-precision approaches; OCA is the obstacle clearance altitude
• B. DA equals MDA; OCA is not used
• C. DH stands for descent height; MDH for maximum descent height
• D. DA is for VFR; MDA for IFR

Answer: (A)

Understanding how these altitudes govern descent and decision points during instrument approaches helps you know when you may descend and what visual references you must have. Decision altitude is the point on a precision approach where you must decide whether you have enough visual references to land or must execute a go-around. With vertical guidance, you descend to this altitude and, if you don’t have the required runway environment and references by then, you go around. Non-precision approaches don’t provide vertical guidance, so you don’t descend below a fixed minimum descent altitude until you have the required visual references to land. Obstacle Clearance Altitude is a separate measure used in the design and depiction of procedures to guarantee obstacle clearance within a defined area along the approach. It’s about ensuring safe clearance from obstacles, even in portions of the approach that may not have vertical guidance. So the correct statement is that DA is the decision altitude on precision approaches, MDA is the minimum descent altitude on non-precision approaches, and OCA is the obstacle clearance altitude. The other descriptions mix up the definitions or use nonstandard terms, which doesn’t match how these concepts are applied in instrument procedures.

Understanding how these altitudes govern descent and decision points during instrument approaches helps you know when you may descend and what visual references you must have.

Decision altitude is the point on a precision approach where you must decide whether you have enough visual references to land or must execute a go-around. With vertical guidance, you descend to this altitude and, if you don’t have the required runway environment and references by then, you go around. Non-precision approaches don’t provide vertical guidance, so you don’t descend below a fixed minimum descent altitude until you have the required visual references to land.

Obstacle Clearance Altitude is a separate measure used in the design and depiction of procedures to guarantee obstacle clearance within a defined area along the approach. It’s about ensuring safe clearance from obstacles, even in portions of the approach that may not have vertical guidance.

So the correct statement is that DA is the decision altitude on precision approaches, MDA is the minimum descent altitude on non-precision approaches, and OCA is the obstacle clearance altitude. The other descriptions mix up the definitions or use nonstandard terms, which doesn’t match how these concepts are applied in instrument procedures.