What is an Airworthiness Directive (AD)?
An Airworthiness Directive (AD) is a product-related airworthiness order issued by the Technical Airworthiness Authority (TAA). An AD may either be permanent or temporary depending on the circumstances or technical problem that originated the requirement for the AD. A notice issued by another airworthiness regulatory authority may be recognized as equivalent to a TAA-issued AD depending on its applicability to a DND-registered aircraft.