A regulatory document which identifies aeronautical products in which an unsafe condition exists or where the condition is likely to exist or develop in other products of the same type design. It prescribes corrective actions to be taken or the conditions or limitations under which the products may continue to be operated.
ICAO, DOC 9760/2 Airworthiness Manual, Volume II — Design Certification and Continuing Airworthiness 2001, 1st ed., p. IIB-1-1, Chap. 1 (Def.)
The airworthiness directive is the most commonly encountered form of the 'mandatory continuing airworthiness information' mentioned in Annex 8.