航機起降與跑道接觸長度計算模式之建立與應用

Application of aircraft contacting ground runway length computing model

張彥文(Yen-Wen Chang)

指導教授 ： 周家蓓

國立臺灣大學/工學院/土木工程學研究所/碩士(2010年)

https://doi.org/10.6342/NTU.2010.01132

摘要

由於航機的運行環境及載客性質，一旦發生事故所產生的損失往往極為巨大，因此飛航安全一向以來均是交通運輸安全的重要議題。就國際記錄，歷年發生的航空事故有很大的比例發生於航機起飛與降落階段，而影響最直接相關的跑道環境因子便是跑道長度。航機在機場進行起飛和降落作業時，跑道長度與安全區域是否足夠、表面條件是否良好，皆對起降時事故的發生有很大的影響。對機場而言，提供足夠的跑道長度和安全區域面積，並維持其鋪面有足夠的安全性能是維護航機起降安全的必要工作，但對於各機場而言，卻難以對跑道環境改善之手段進行其對實際衝出跑道之風險降低程度進行量化。因此本研究之目標為建立一能有效計算航機起降與地面接觸距離之計算模式，以供機場能藉此量化各種因素對航機起降安全之影響，進而提升飛航安全。
為使本研究所建立之航機起降與地面接觸距離計算模式能夠具有較高之準確性且能考量於現實中各種不同之環境因素，本研究除針對各種有關航機起降煞停距離計算及各種影響航機起降之環境因素之文獻進行蒐集外，亦針對與機場跑道抗滑值相關之文獻進行蒐集，以期能提供將抗滑值之改善運用於計算模式中進行風險評估。此外，為使本研究所建立之計算模式能符合實際情況並了解航機起降之行為模式，本研究除與資深機師進行訪談外，更進入機場塔台上進行航機起降之實際拍攝，並配合航機資料進行計算模式之驗證與修正。
由本研究進行之航機起降觀測中，可得知機場藉由著陸區標範圍及標線之設計使航機降落之落地點分佈較為集中，而航機起飛離地點則無此種引導及限制，故具較大之不確定性。且發現部分航機之降落超過著陸區範圍，具有較大之風險。並發現航機於距跑道端越遠之滑行道滑出時，其減速趨勢越緩，亦即航機於越充裕之距離進行煞停，其所採用之煞停強度便會越小。
應用本研究所建立之計算模式進行航機起降之風險分析之結果可發現，反推力之使用與否和跑道道面狀況之良劣對航機取消起飛及正常降落情境下衝出跑道之風險具有決定性之影響，且發現跑道煞停摩擦係數由0.4降至0.1時，將使航機正常降落之煞停距離增加為1.8倍，且增加之比例於濕跑道上更為明顯。
於現有機場跑道長度並不充裕之情形下對於降低航機起降風險之改善措施，本研究建議應可由航機較重時之設備與操作管理、抗滑值之提升以及航機起降行為限制部分著手。對於大雨造成跑道濕滑等易發生衝出跑道事故之高風險環境下，應有效針對具有高風險重量之航機進行操作管制。且各機場平時應依照規範進行抗滑值之養護，並建議將抗滑值維持於較高之水準而非僅達規範標準。應對航機於濕滑跑道等高風險環境下設立一限制其減低推力之門檻，以使其能於發生引擎損壞、反推力失效等意外下仍舊能安全於跑道內完成煞停；除此之外，應於著陸區範圍之限制外，另行對機師違反限制之情形進行規範，以降低航機降落因落地點過遠而發生衝出跑道之風險。
本研究建立計算模式之參數模型僅限定為波音747-400機型，未來若需針對不同機場之航機起降距離進行計算，可依各不同機場之設計機型調整計算模式之參數，以使其結果符合實際情形。除此之外，若能進行更為大量之航機起降觀測，將可更為完善本研究所建立之計算模式。

關鍵字

跑道安全 ； 煞停距離 ； 起飛 ； 降落

並列摘要

Due to the aircraft's operating environment and the characters, the aviation safety has become an important issue of transportation security. There is a large proportion of flight accidents occurred during landing and takeoff. In the landing or takeoff phase of flight accidents, the most direct factor related to aviation safety is the runway length and the runway surface. For the airports, it is necessary to maintain adequate security of pavement performance and provide adequate runway length and safety areas, but it is difficult to evaluate the actual quantified degree for the runway improvement.
This research proposed an effective computing model for the airplane contacting ground distance in takeoff and landing phase. By using this model, we can quantify the effects causing from various factors which related to aviation safety. In order to establish the computing model with higher accuracy and reflecting reality, this research collected the literatures about airplane stopping distance and the environmental impact factors for taking off and landing. Furthermore, we also refer the literatures about skid resistance to provide the skid number for risk analysis, which is one of the computing model’s various functions.
This research not only conducted interview with experienced pilot, but also access to the airport for airplane takeoff and landing filming. All these works above assist the verification and correction of the computing model.
By the observation in this research, we figured out that the landing points are more concentrated than those of takeoff. This phenomenon attributes to the limitation and guidance restricted by the marking of landing area. Furthermore, we found that some of the airplane land over the landing area, and this situation made larger risks for overrun. Another finding is that the airplane deceleration depends on the target taxiway, so the smaller intensity of braking happened when the available stopping distance is larger.
By applying this computing model, we discovered that both the reverse thrust usage and the runway pavement condition effects the risk of airplane takeoff and landing. Also, we did the risk analysis to find that the airplane braking coefficient’s impact on stopping distance is more significant in the wet runway, and the ratio is 1.8 that the braking coefficient decreases from 0.4 to 0.1.
For those airports whose runway length is not abundant, the suggested improvements are controlling the takeoff weight, increasing the skid number, and restricting the airplane takeoff and landing behavior. We should control the process of landing and takeoff carefully in high-weight airplanes in the wet and slippery runway to make sure the aviation safety, and the skid resistance of runway should be kept in a high level to avoid the risk of overrun. In addition, we should take more limitations on pilots when landing to decrease the opportunity of landing over the landing area to decrease the airplane overrun risk.
However, the computing model in this research is constructed by Boeing 747-400, and there are many airports which are not using Boeing 747-400 as their critical design airplane. As a result, we should gather up more airplanes’ parameters and more experiments in reality to simulate different conditions to increase the safety of airplanes and airports.

並列關鍵字

Runway safety ； Airplane Runway length ； Takeoff ； Landing

參考文獻

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