Regulations of Airworthiness and Maintenance Management for Aviation Products, Appliances and Parts Article 20
Except for the free balloons, It is required that aircraft must be weighed for basic empty weight and balance once every three years, the weighing schedule may be extended with the approval from the CAA under special circumstances, but the extension can not exceed 1 year.Upon changes to the accumulation of basic empty weight of the aeroplane more than 0.5 percent of maximum landing weight or shifting of center of gravity more than 0.5 percent of mean aerodynamic chord, the aircraft shall be weighted. Upon changes to the basic empty weight of the helicopter more than 0.5 percent of maximum landing weight, the aircraft shall be weighted.In the case when the center of gravity or weight of the aircraft is changed after the completion of the above-mentioned weighing process, owner or operator is required to have their relevant weight and balance manuals revised to be in accordance with Aircraft Flight Operation Regulations.
中文原文 航空產品與其各項裝備及零組件適航維修管理規則第20條
除自由氣球外，航空器應每三年接受基本空重之稱重一次。
但因特殊情形報經民航局核准者，得酌予延展稱重期間，其延展期間最長不逾一年。
飛機基本空重改變累積增減達其最大落地重量千分之五，或使其重心位移達平均氣動力弦千分之五者，應重新稱重；直昇機基本空重改變達其最大落地重量千分之五者，應重新稱重。
依前二項規定完成稱重之航空器，其重心或重量產生變化者，航空器所有人或使用人應依航空器飛航作業管理規則修正載重平衡作業相關手冊。
但因特殊情形報經民航局核准者，得酌予延展稱重期間，其延展期間最長不逾一年。
飛機基本空重改變累積增減達其最大落地重量千分之五，或使其重心位移達平均氣動力弦千分之五者，應重新稱重；直昇機基本空重改變達其最大落地重量千分之五者，應重新稱重。
依前二項規定完成稱重之航空器，其重心或重量產生變化者，航空器所有人或使用人應依航空器飛航作業管理規則修正載重平衡作業相關手冊。