航班起飞过程的风险识别与控制

Risk recognizing and control for flight takeoff

飞机起飞阶段是事故多发阶段,为了进行风险识别与控制,设计了定性判别方法和定量计算仿真算法,并以具体飞机坠毁事故为例分析了安全裕度。分别计算了飞机冲出跑道的速度、距离和逃生时间。中断起飞的速度与时间,是火灾发生后的判断关键,也构成了飞机起飞事故的裕度。结果表明,中断起飞的安全裕度比坠毁的大,且关于中断起飞的规定有矛盾之处;用于逃生的90s规则高于中断起飞的决断速度的限制规定。该分析方法为处理危急时刻的两难决策问题提供了理论指导。

The present paper is aimed to introduce a quantitative and qualitative simulation algorithm developed by its authors for observing and calculation of the velocity and the taking-off distance. It is wellknown that there have been exiting or hard-nuts or troubles in riskrecognition and control in the takeoff stage of the airliners, which in turn may lead to disastrous accidents. In hoping to work out an approach to more efficiently recognize the hazards on the high-speed running, we have done a lot of qualitative and quantitative testing and measurements so as to develop a method which is in a position to demonstrate the safety conditions and the likely-to-be-recognized errors beyond the control power of the pilots. In proceeding with our research, we have taken a specific event as one of our case studies. As a matter of fact in aviation practice, the safety margin is related with the time and the speed. As is known, the traditional time requirement for evacuation is 90 seconds, which means the extreme urgency and narrow escape possibility if anything disastrous would happen. The simulated results of ours reveal that the margin of aborted takeoff is higher than the machine crash-down, which may lead less harm to their passengers. Since there may exist exit-neglect for the real or highly probable accidents in the conventional regulation for the rejected takeoff when a high-speed running accident takes place, it is of great necessity for the pilot to promptly recognize the abnormal conditions. Detailed comparison made between the 90 seconds requirement for evacuation and the regulations for the aborted taking-off lead us to the discovery that the 90 second requirement for evacuation has the higher order than the V1 limitation, which implies first of all the realistic danger likely for the pilot and the passengers to be confronted with. On the other hand, the given quantitative and qualitative simulation algorithm can naturally be taken to serve as a guide for the flight training and decision-making in the urgent case with some dilemma.