贝尔505直升机总距杆疲劳安全适航指令研究

Research on Fatigue Safety Airworthiness Directives of Bell 505 Helicopter's Collective Stick

针对近期加拿大民航当局就贝尔505直升机总距杆断裂发出了多份紧急适航指令的事件,在深入分析该机型飞行操纵系统、液压系统和旋翼系统的设计特征的基础上,总结了其地面操纵行程检查中总距操纵力的特点,同时分析了该系列紧急适航指令颁布的发展变化历程和总距杆疲劳断裂原因,给出了疲劳安全适航指令颁布和直升机飞行操纵系统操纵线系及操纵装置疲劳安全设计的相关建议,指出需要注意地面使用维护和检查过程中产生的非飞行疲劳载荷因素。上述研究成果可用于紧急适航指令的颁布和适航审定安全风险的识别处理。

For the recent incident that Canadian civil aviation authority issued multiple emergency airworthiness directives against the break of Bell 505 helicopter's collective stick,this paper analyzes the design features of the flight control system,hydraulic system and rotor system of the aircraft,and summarizes the characteristics of the collective pitch control force in the ground full control movement inspection.At the same time,the development history of this series of emergency airworthiness directives and the reasons for the fatigue fracture of the collective stick are analyzed.The relevant suggestions for the issuance of the fatigue safety airworthiness directives and the fatigue safety design of the control route lines and inceptors of the helicopter flight control system are given.It is necessary to pay attention to the none flight fatigue load factors produced in the process of ground maintenance and inspection.The review results of the above-mentioned emergency airworthiness directive events can be used in the promulgation of emergency airworthiness directive and to identify and deal with the safety risks in airworthiness certifications.