Aircraft Flight Operation Regulations Article 89
Performance of helicopters during approach and landing phase shall meet the following requirements:1. Operations in performance Class 1. In the event of the failure of the critical power-unit being recognized at any point during the approach and landing phase, before the landing decision point (LDP), the helicopter shall, at the destination and at any alternate, after clearing all obstacles in the approach path, be able to land and stop within the landing distance available or to perform a balked landing and clear all obstacles in the flight path by an adequate margin equivalent to that specified in Article 87, subparagraph 1. In case of the failure occurring after the landing decision point (LDP), the helicopter shall be able to land and stop within the landing distance available.2. Operations in performance Class 2. The helicopter shall be able, with all power units operating, clearing all obstacles along the flight path by an adequate margin and to land at landing area. In the event of the failure of the critical power-unit before the defined point before landing (DPBL), the helicopter shall, at the destination and at any alternate, after clearing all obstacles in the approach path, be able either to land and stop within the landing distance available or to perform a balked landing and clear all obstacles in the flight path by an adequate margin equivalent to that specified in Article 87, subparagraph 2. After the defined point before landing (DPBL), failure of a power-unit may cause the helicopter to force-land; therefore, the conditions stated in Article 85 shall apply.3. For performance class 3 helicopters. The helicopter with all power-units operating shall, at the destination and any alternate, after clearing all obstacles in the approach path by a safe margin, be able to land and stop within the landing area or to perform a balked landing and clear all obstacles in the flight path by an adequate margin, equivalent to that specified in Article 87, subparagraph 3. At any point of the flight path, failure of a power-unit will cause the helicopter to force landing; therefore, the conditions stated in Article 85 shall apply.
中文原文 航空器飛航作業管理規則第89條
直昇機於進場及降落階段之性能應符合下列規定：
一、一級性能直昇機於進場及降落階段發生關鍵動力機件失效時，應能於到達降落決定點之前，以安全高度超越進場航路上所有障礙後，降落於降落區內或以第八十七條第一款規定之高度超越航路上所有障礙後，中止降落執行重飛。
但於降落決定點後發生關鍵動力機件失效時，應能降落於降落區內。
二、二級性能直昇機於動力機件正常運作情況下，應能以安全高度超越進場航路上所有障礙後，降落於降落區內，或以第八十七條第二款規定之安全高度超越航路上之有障礙後，中止降落執行重飛。
於降落臨界點之前發生關鍵動力機件失效時亦適用之。
但於臨界點之後發生動力機件失效需迫降時，應符合第八十五條之規定。
三、三級性能直昇機於動力機件正常運作之情況下，應能以安全高度超越進場航路上所有障礙後，降落於降落區內，或以第八十七條第三款規定之安全高度超越航路上之所有障礙後，中止降落執行重飛。
但於航路上發生動力機件失效需迫降時，應符合第八十五條之規定。
一、一級性能直昇機於進場及降落階段發生關鍵動力機件失效時，應能於到達降落決定點之前，以安全高度超越進場航路上所有障礙後，降落於降落區內或以第八十七條第一款規定之高度超越航路上所有障礙後，中止降落執行重飛。
但於降落決定點後發生關鍵動力機件失效時，應能降落於降落區內。
二、二級性能直昇機於動力機件正常運作情況下，應能以安全高度超越進場航路上所有障礙後，降落於降落區內，或以第八十七條第二款規定之安全高度超越航路上之有障礙後，中止降落執行重飛。
於降落臨界點之前發生關鍵動力機件失效時亦適用之。
但於臨界點之後發生動力機件失效需迫降時，應符合第八十五條之規定。
三、三級性能直昇機於動力機件正常運作之情況下，應能以安全高度超越進場航路上所有障礙後，降落於降落區內，或以第八十七條第三款規定之安全高度超越航路上之所有障礙後，中止降落執行重飛。
但於航路上發生動力機件失效需迫降時，應符合第八十五條之規定。