AD

Airworthiness Directive

In the context of aviation and aerospace, an "Airworthiness Directive" (AD) is a regulatory document issued by a national aviation authority, such as the Federal Aviation Administration (FAA) in the United States, to ensure the continued airworthiness of an aircraft, engine, propeller, or appliance.

Airworthiness directive (FAA)

In the context of aviation and aerospace, an Airworthiness Directive (AD) is a regulatory requirement issued by the Federal Aviation Administration (FAA) in the United States, or by similar regulatory bodies in other countries, to ensure the airworthiness of an aircraft, aircraft engine, or aircraft component.