What is the purpose of an Airworthiness Directive (AD)?

• A. It provides guidance and information to owners and operators of aircraft informing them of the discovery of a condition that prevents the aircraft from continuing to meet its conditions for airworthiness.
• B. It lists new model aircraft.
• C. It defines flight crew rest requirements.
• D. It describes how to perform an emergency landing.

Answer: (A)

Airworthiness Directives are issued when an unsafe condition is found to exist in a certificated aircraft, engine, propeller, or related part. Their purpose is to inform owners and operators about that condition and to require specific actions to correct it and restore airworthiness. An AD spells out what is affected, the safety problem, and the exact actions needed (such as inspections, repairs, modifications, or replacements) along with timeframes or repetitive intervals. They are legally enforceable, so compliance is mandatory to keep the aircraft considered airworthy. This is different from generic guidance or model listings and from procedures like emergency landing instructions—the AD’s core function is to mandate corrective measures to prevent unsafe operation.