Canadian Aviation Regulations

593.02 Unless the Minister considers that an alternative action to an airworthiness directive will ensure an equivalent level of safety, the Minister shall issue, in the form and manner set out in chapter 593 of the Airworthiness Manual, an airworthiness directive in respect of an aeronautical product for which a type certificate has been issued, or accepted, by the Minister where

• (a) an unsafe condition exists in the aeronautical product and the condition is likely to exist or develop in other aeronautical products;

• (b) it has been found, subsequent to the issuance of the type certificate, that the aeronautical product does not conform to the requirements of the basis of certification for the type design of the aeronautical product;

• (c) it is necessary to modify or cancel the requirements of an airworthiness directive issued by a civil aviation authority having jurisdiction over the type design of the aeronautical product because the Minister considers the airworthiness directive inappropriate for reasons related to the environment, safety, the delayed receipt of an instruction issued by a foreign civil aviation authority or reliance on foreign legislation; or

• (d) it is necessary to modify or cancel a Canadian airworthiness directive that is in force, because a condition referred to in any of paragraphs (a) to (c) has changed or ceased to exist.