Airport foldable and fragile pole application scope: The supporting structures of all aids to navigation equipment within the runway obstruction area limits.
Fragile and brittle items — objects that will break (shatter), bend, or yield under specified impact forces, thereby becoming less harmful lightweight objects to aircraft.
Fragility
Various visual and non-visual navigation facilities at airports (such as approach light towers, meteorological equipment, radio navigation equipment, etc.) are generally located near runways, taxiways, and aprons. If aircraft operating on the ground during takeoff or landing collide with them unintentionally, it could pose a hazard. All such equipment and their supports must be collapsible and installed as low as possible to ensure that collisions do not lead to aircraft control loss. Collapsibility can be achieved through various design concepts, such as using lightweight, easily collapsible, and fragile materials, brittle and low-toughness components and fasteners, etc., to ensure that collapsible objects break, bend, or yield upon impact.
Flexible and fragile poles (hereinafter referred to as "flexible poles") are support structures made in single-pole, tower, and other configurations, utilizing lightweight, fragile materials and a design that is prone to bending.
Condition for bendability of aviation easily breakable and fragile rods
For aircraft with potential for non-lift and non-landing, the breakable rod must be susceptible to breakage upon impact from an aircraft weighing 3,000 kg and traveling at 140 km/h. For aircraft with potential for non-ground sliding, the breakable rod must also break upon impact from an aircraft weighing 3,000 kg and traveling at 50 km/h. The force exerted by the breakable rod on the aircraft during impact should not exceed 45 KN; the energy transferred to the aircraft by the breakable rod should not exceed 55 KJ.