The Organization Act of the Taiwan Transportation Safety Board Article 4
When the Chairperson's position is vacant or the Chairperson is unable to perform his or her duties, the Vice Chairperson shall be the acting Chairperson. When both the Chairperson and Vice Chairperson's positions are vacant or they are unable to perform their duties, the Premier shall designate one of the Board Member as the acting Chairperson.
中文原文 國家運輸安全調查委員會組織法第4條
主任委員出缺或因故無法行使職權時，由副主任委員代理；主任委員、副主任委員均出缺或因故無法行使職權時，由行政院院長指定委員一人代理主任委員。