Airworthiness Directive will includes;
• A description of the unsafe condition
• The product to which the Airworthiness Directive applies
• The corrective action required
• Date of compliance
• Where to get additional information
• Information on alternative methods of compliance if applicable.
(FAA) There are 4 categories of Airworthiness Directive, each with their own effective date
and method of notice to affected owners;
• Notice of Proposed Rule-Making (NPRM)
• Immediate Adopted Rule
• Emergency AD
• ADs issued to other than aircraft.