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Airworthiness Directives (ADs) are a set of legally enforceable rules that apply to aircraft and the following aircraft products: engines, propellers, and equipment, such as; parachutes, seat belts, and fire extinguishers.An Airworthiness Directive (AD) is a document
They are mandatory instructions, issued by the Minister of Transport or a foreign airworthiness authority, that amend an approval document relating to an aeronautical product which may require modification, replacement or special inspection to ensure that it complies with approved design data and is in a condition for safe operation.
They are documents issued or adopted by the Civil Aviation Authority of the State of Registry of an a given aircraft. For example, TC will adopt all FAA AD’s issued against Boeing products as the USA is the type certificate holder (TCH) for Boeing, and the Canadian aircraft register contains Boeing products.
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