What type of airworthiness directive requires immediate action?

The type of airworthiness directive that requires immediate action is an emergency directive. Emergency directives are issued when there is a situation that poses an immediate risk to safety or potential safety issues that could lead to serious incidents or accidents if not addressed promptly. These directives mandate that owners/operators take specific actions without delay, often involving inspections, repairs, or modifications to aircraft to ensure safety.

The urgency associated with emergency directives contrasts with other types, such as recurring directives, which typically require actions at specified intervals but do not necessitate immediate intervention. One-time directives might address issues that require attention but are not deemed critical for immediate safety. Final Rule directives might establish permanent regulations or guidance, but they also do not carry the same immediacy as emergency directives. Thus, the nature of the emergency directive is defined by its requirement for rapid response to mitigate significant safety risks.