No person may import appliances and parts for civil aviation use unless properly certificated. The holder of an appliance and part shall use the procedures in Attachment 18 for the validation of imported appliances and parts, unless otherwise prescribed in a treaty or an agreement.Airworthiness approvals that were issued by the airworthiness authority of the exporting country shall be attached with the imported appliances and parts.Attachment 18 Appliance Design Validation Procedure.odt