What is the primary purpose of an airworthiness directive (AD)?

The primary purpose of an airworthiness directive (AD) is to notify aircraft owners and operators about specific unsafe conditions that may exist in aircraft, as well as to outline the necessary corrective actions that must be taken to ensure safety. ADs are issued by aviation authorities, such as the Federal Aviation Administration (FAA) in the United States, when a safety concern or defect has been identified which could affect the operation of an aircraft. This process is critical for maintaining the safety and integrity of aircraft in service, ensuring that issues are addressed promptly to prevent accidents.

Other options do not accurately reflect the function of an AD. For instance, while enhancing aircraft performance and scheduling regular service checks are essential aspects of aircraft maintenance, they do not address safety issues directly related to airworthiness. Additionally, financial guidance does not pertain to the mandate of airworthiness directives, which focus solely on safety and compliance in aviation.