Civil Aviation Act Article 15
In case a registration or airworthiness certificate becomes invalid, CAA shall serve a public notice of its cancellation, and the holder of such certificate shall return it to CAA within twenty days from the date of invalidation.
中文原文 民用航空法第15條
登記證書或適航證書失效時，由民航局公告作廢。
持有人並應自失效之日起二十日內，向民航局繳還原證書。
持有人並應自失效之日起二十日內，向民航局繳還原證書。