What is an Airworthiness Directive (AD)?

An Airworthiness Directive (AD) is a legally enforceable rule issued by the Federal Aviation Administration (FAA) to address safety issues or defects in aircraft, engines, propellers, and other components that could affect the airworthiness of an aircraft. When an AD is issued, it requires operators to make specific alterations, repairs, or inspections to ensure safety and compliance with aviation standards.

The intent of an AD is to mitigate identified hazards, often stemming from incidents, service history, or technical analysis that reveals safety concerns. Compliance with ADs is critical, as they are not optional; they mandate that certain actions be taken within specified time frames to maintain the aircraft's airworthiness. This distinguishes ADs from notifications for voluntary inspections, maintenance recommendations, or guides for flight maneuvers, which do not carry the same legal obligation and enforcement.