航機延誤擴散之預測--SIMMOD模擬模式之應用分析

Abstract

機場發生起降方向轉變或因天氣因素而關閉，使得航機必須延後起降或停止起降時，相關單位若能確實預估後續航機之延誤狀況，對其運作與設備及人員調度上之需要，是很有幫助的。本研究首先以SIMMOD模擬模式構建松山機場與小港機場之空邊與空域系統，並以嚴謹之統計方法進行模式之校估與驗證，使模式能夠表現實際運作狀況。之後，以此模式進行起降方向轉變下，機場運作及航機起降延誤之分析。在起降方向轉變下，因為系統運作過渡的需要，使得在起降方向轉變後最初十五分鐘的時段內，航機只能起降二至三架次，其餘預定在此時段起降之航機，必須延後至之後的時段起降，造成航機起降延誤的擴散。另外，在調整不同的進場航機隔離標準後發現，管制員若能視離到場航機需求量之不同，適時調整進場航機間之隔離，不但能使首架離場航機的延誤時間減少21%，且能有效地降低航機延誤擴散所需收斂的時間。

配合航管作業之實際情況，本研究根據模擬結果，分別推導在起降方向轉變以及機場關閉情境下，個別離進場航機預估延誤時間之延誤模式。延誤分為兩種：包括因來機延誤或地面作業時間不足而產生之後推延誤，以及因為天候異常狀況而產生的離（進）場等候延誤。首架離（進）場航機之等候延誤時間，與在起降方向轉變下，系統運作過渡所需時間，以及在機場關閉情境下，機場關閉時間的長短有關。後續離（進）場航機延誤時間之收斂情況，則與機場容量與班表累積流量之差值有關。在不同的航機流量與影響時間下，比較SIMMOD模式在五種不同的情境下輸出之數值與本研究所推導延誤模式計算之數值，得兩者之誤差平均僅為0.235分鐘，顯示本研究所推估之延誤模式，能有效地預估在天候異常情況下，航機所預期之延誤時間。

It’s important for airport operators, airlines crew and air traffic controllers（ATC） to predict the flight delays in abnormal weather conditions. In this research, a SIMMOD-based multi-airport simulation model system, including both Taipei and Kaohsiung airports as well as the airspace in between, is developed, calibrated and validated using the ATC data and observed operational data. It is applied for analyzing the performance of airport operations and the flight delays due to runway direction change. The result demonstrates that because of the required transitional operations from one network configuration to the other, only two or three flights could be allowed to use the runway in the first 15 minutes after the runway direction change. As a consequence, the following flights would somehow be delayed. In addition, the simulation shows that if ATC could separate the arrivals effectively, the first departure flight could reduce delay by 21%, and the total propagation time could be shortened.

On the basis of the outputs of the simulation, a mathematical delay model is derived. To estimate the expected delays of each flight, for both runway direction change and airport closing, two kinds of delays：push-back delays due to inbound-flight delays or insufficient scheduled ground time, and departure（arrival）delays due to abnormal weather conditions are considered in the model. The departure（arrival）delays of the first flight is subject to the duration of operation transition or airport closing, and the constringency of the delays of the succeeding flights is subject to the difference between the airport capacity and accumulated scheduled flights. Compared to the outputs of the SIMMOD model, the delays derived from the mathematical formulas are rather accurate. The average error is 0.235 minute in five different scenarios. This suggests that the formulas can be used to forecast flight delays, and with this information, better decisions can be made in advance.