What are Airworthiness Directives classified as?

Airworthiness Directives (ADs) are formal communications issued by the Federal Aviation Administration (FAA) that provide mandatory requirements for maintaining the airworthiness of an aircraft. Classified under Federal Aviation Regulations, ADs are legally enforceable and must be adhered to by aircraft owners and operators. They are issued in response to safety concerns related to aircraft design, maintenance practices, or operational requirements.

ADs may originate from various factors, such as findings in accident investigations, service experience, or recommendations from manufacturers. However, unlike guidelines or recommendations, the compliance with ADs is not optional; they come with the force of law, and non-compliance can result in penalties, including grounding an aircraft until the necessary actions are taken. This classification as part of Federal Aviation Regulations underscores their critical role in ensuring aviation safety and the operational integrity of aircraft.