Rules of the Air Article 48
A controlled flight shall, except when landing at a controlled aerodrome, advise the appropriate ATC unit as soon as it ceases to be subject to air traffic control service.
中文原文 飛航規則第48條
管制飛航航空器除已降落於管制機場，當無需航管服務時，應儘速告知有關航管單位。