To descend below ACA, which is required?

To descend below ACA, which is required?

• A. You may descend below ACA if you can see the runway
• B. Clearance is not required to descend below ACA
• C. You must have clearance to land to descend below ACA
• D. ATC instruction suffices to descend

Answer: (C)

The key idea is that the protected area around the airport (the ACA) requires explicit permission to descend through it. You must have a landing clearance before you descend below the ACA. Even if you can see the runway, that visual cue does not substitute for the required clearance. An ATC instruction to descend may move you toward the area, but it does not by itself authorize penetrating the ACA; only a landing clearance confirms you are cleared to descend and land. This is why the correct choice is that you must have clearance to land to descend below the ACA.

The key idea is that the protected area around the airport (the ACA) requires explicit permission to descend through it. You must have a landing clearance before you descend below the ACA. Even if you can see the runway, that visual cue does not substitute for the required clearance. An ATC instruction to descend may move you toward the area, but it does not by itself authorize penetrating the ACA; only a landing clearance confirms you are cleared to descend and land. This is why the correct choice is that you must have clearance to land to descend below the ACA.