In order to keep the validity of the airworthiness review staff authorisation, the airworthiness review staff should have either: been involved in continuing airworthiness management activities for at least six months in every two year period, or conducted at least one airworthiness review in the last twelve month period. In order to restore the validity of the authorisation, the airworthiness review staff should conduct at a satisfactory level an airworthiness review under the supervision of the competent authority or, if accepted by the competent authority, under the supervision of another currently valid authorised airworthiness review staff of the concerned continuing airworthiness management organisation in accordance with an approved procedure.