Under what circumstances would compliance with an AD not be required?

Compliance with an Airworthiness Directive (AD) is a crucial aspect of aircraft maintenance aimed at ensuring safety and compliance with regulations. The situation where compliance with an AD is not required occurs if the action specified in the directive has already been accomplished before the effective date of the AD.

This is significant because the intent of an AD is to address safety concerns that may arise after the issuance of the directive. If the required actions have already been completed, there would be no need for the aircraft owner to take further action regarding that specific AD, thereby ensuring that the aircraft remains in compliance with safety standards without unnecessary redundancy.

The other options do not provide valid grounds for non-compliance with an AD. For instance, maintenance hours or the sale of the aircraft does not negate the requirement; ADs apply continuously regardless of operational status or ownership changes. Similarly, a pilot's request for exemption does not alter the need for compliance, as ADs are regulatory requirements that must be followed to ensure aircraft safety.