跑道水膜深度即時預測與航機衝偏出跑道事故預防之探討

Investigation into Real-Time Prediction of Runway Water Film Depth and Its Role in Preventing Runway Excursion Incidents

航機衝偏出跑道為過去全球最重要事故類型，研究顯示跑道狀況及天氣因素與衝偏出跑道肇因高度相關，其中因跑道積水，造成航機使用較長落地距離而衝出跑道，或航機方向控制不易而偏出跑道，過程中可能有水飄現象，國際民航組織要求機場管理者須提供跑道超過3mm之水深即時資訊予航機駕駛員，惟利用儀器或人工量測均有成本及安全考量。本研究以實驗方式在變化跑道橫坡度、距中心線長度、平均紋理深度及降雨量等參數，以高精度儀器量測跑道水膜深度，使用模糊邏輯建模（fuzzy logic modeling）方法建立預測模型，並運用於國籍航空器衝偏出跑道之事故進行驗證及分析，作為機場跑道積水通報策略之參考。

Runway excursion has been one of the most significant types of aviation accidents worldwide over the past several decades. Studies have shown a strong correlation between runway surface conditions, meteorological factors, and the occurrence of such events. In particular, rain and water accumulation on the runway surface can lead to longer landing distances, resulting in runway overruns, or reduced directional control, causing aircraft to veer off the runway. During such events, hydroplaning may also occur. To address this, the International Civil Aviation Organization (ICAO) mandates that airport operators provide real-time information on runway water film depth (WFD) to pilots when the depth exceeds 3 mm. However, measuring runway WFD - either by instruments or manual methods - poses considerable challenges and incurs high costs. This study conducted experiments under various conditions, including runway transverse slopes, distances from the centerline, mean texture depths, and rainfall intensities, and using high precision instruments to measure WFD on the runway. The WFD data collected through the experiment is used to establish a WFD prediction model using the fuzzy logic modeling method. This established model was further validated and analyzed using historical runway excursion occurrence of domestic registered aircraft that were attributed to wet and slippery runway conditions. The results of this study may serve as a reference for developing runway water accumulation reporting strategies and practical operational procedures at airports.