Aircraft Flight Operation Regulations Article 214
For a flight to be conducted in accordance with the instrument rules, at least one destination alternate aerodrome shall be selected and specified in the flight plan unless:1. Estimated destination has standard instrument arrival procedures.2. The latest weather information indicates that one hour before and after the estimate time of arrival at the aerodrome, the approach and landing may be conducted under the following visual meteorological conditions (VMC):a) For airplane: a cloud base of at least 1,000 ft above the minimum associate with the instrument approach procedure and a visibility of at least 5.5km or 4km more than the minimum associated with the procedure.b) For helicopters: a cloud base of at least 400.ft above the minimum associate with the instrument approach procedure and a visibility of at least 1.5km more than the minimum associated with the procedure.3. If helicopter flight to an aerodrome of intended landing is isolated and there is no suitable destination alternate aerodrome. The flight plan shall include a selected point of no return.4. For helicopters flight, the isolated destination has standard instrument arrival procedures.
中文原文 航空器飛航作業管理規則第214條
依儀器飛航規則製作之操作飛航計畫，除下列情況外，至少應列有一處備用機場：
一、預定降落機場已訂有標準儀器進場程序。
二、所獲得之最新氣象資訊顯示，預定到達目的地機場時間前後一小時內之氣象狀況符合下列規定：
（一）飛機：雲幕高超過儀器進場程序最低限度一千呎以上，能見度至少五點五公里或超過儀器進場程序最低限度四公里以上。
（二）直昇機：雲幕高超過儀器進場程序最低限度四百呎以上，能見度超過儀器進場程序最低限度一點五公里以上。
三、目的地機場係一孤立區域，無適當之備用機場者。
但直昇機之操作飛航計畫應設定一不得轉回點。
四、以直昇機飛航時，該孤立機場應已備有儀器進場程序。
一、預定降落機場已訂有標準儀器進場程序。
二、所獲得之最新氣象資訊顯示，預定到達目的地機場時間前後一小時內之氣象狀況符合下列規定：
（一）飛機：雲幕高超過儀器進場程序最低限度一千呎以上，能見度至少五點五公里或超過儀器進場程序最低限度四公里以上。
（二）直昇機：雲幕高超過儀器進場程序最低限度四百呎以上，能見度超過儀器進場程序最低限度一點五公里以上。
三、目的地機場係一孤立區域，無適當之備用機場者。
但直昇機之操作飛航計畫應設定一不得轉回點。
四、以直昇機飛航時，該孤立機場應已備有儀器進場程序。