维修机械师在维护飞机时，往往要冒着坠落的危险坐到飞机的机身顶部或悬吊在机翼前缘上。由于飞机设计气动外形上的需要，使许多零部件维护起来很困难。同时由于飞机及机库的外形及尺寸各种各样，所以有时很难找到适合各种不同情况下所需的防止维修人员从飞机上坠落下来的防护 Maintenance mechanics often take the risk of falling to the top of the airplane’s fuselage or hang on the wing’s leading edge while maintaining it. Due to the aerodynamic shape requirements of aircraft design, many parts are difficult to maintain. At the same time, due to the various shapes and sizes of aircraft and hangars, it is sometimes difficult to find a suitable protection for maintenance personnel from falling down in the aircraft in various situations