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An Airworthiness Directive (AD) is a document issued or adopted by the Civil Aviation Authority of the State of Registry of an aircraft (Type Certificate Holders - TCH).
An AD mandates actions to be performed to restore an acceptable level of safety to an aircraft, when evidence shows that the safety level may otherwise be compromised.
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Identification of the affected aircraft by manufacturer/model association.
Actions required to restore the aircraft to an acceptable level of safety.
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The condition is likely to exist or develop in other aircraft of similar type.
Application and responsibilities of an Airworthiness Directive are as follows:
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