Airport foldable and fragile pole application scope: The supporting structures of all auxiliary navigation equipment in the runway obstruction limiting surface.
Fragile and brittle items — may break (shatter), bend, or yield under specified impact forces, thereby becoming a relatively lightweight object that poses minimal harm to aircraft.
Crip proneness
Visual and non-visual navigation facilities at airports (such as approach light towers, meteorological equipment, radio navigation equipment, etc.) are typically located near runways, taxiways, and aprons. If an aircraft in takeoff or landing ground operations were to collide with them unexpectedly, it could pose a danger. 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 brittle materials, components, and connectors with low toughness, to ensure that the collapsible objects break, bend, or yield upon impact.
Flexible and fragile pole structures (hereinafter referred to as "flexible poles") are support structures made in single-pole, tower-like, and other configurations, utilizing lightweight, fragile materials and flexible structures.
Condition for bendability of aviation easily breakable and fragile rods
For aircraft that may not take off or land safely and could collide with a flexible rod, the rod must bend and break upon impact from an aircraft weighing 3,000 kg and traveling at 140 km/h. For aircraft that may not glide on the ground and could collide with a flexible rod, the rod must bend and break upon impact from an aircraft weighing 3,000 kg and traveling at 50 km/h. The force exerted by the flexible rod on the aircraft during impact should not exceed 45 kN; the energy transferred to the aircraft by the flexible rod should not exceed 55 kJ.