Aircraft Flight Operation Regulations Article 57
For a flight to be conducted in accordance with the instrument flight rules, at least one destination alternate aerodrome shall be selected and specified in the operational flight plan, unless:1. The duration of the flight is less than 6 hours flight time and the meteorological conditions prevailing are such that at the estimated time of arrival at the aerodrome of intended landing, and for a period one hour before and one hour after such time, approach and landing may be made under visual meteorological conditions (VMC); or2. The aerodrome of intended landing is isolated and there is no suitable destination alternate aerodrome.Helicopters operating under the conditions aforementioned in the subparagraph 2 of the preceding paragraph shall have a point of no return selected and filed in the operational flight plan.
中文原文 航空器飛航作業管理規則第57條
航空器使用人依儀器飛航規則製作之操作飛航計畫中，至少應列有一處備用機場。
但有下列情形之一者，不在此限：
一、飛航時間少於六小時且目的地機場之天氣情況，於預計到達之前後一小時內，符合目視天氣情況。
二、目的地機場係一孤立區域，無適當之備用機場者。
直昇機於前項第二款之情形下，其操作飛航計畫應設定一不得轉回點。
但有下列情形之一者，不在此限：
一、飛航時間少於六小時且目的地機場之天氣情況，於預計到達之前後一小時內，符合目視天氣情況。
二、目的地機場係一孤立區域，無適當之備用機場者。
直昇機於前項第二款之情形下，其操作飛航計畫應設定一不得轉回點。