Airport foldable and fragile pole application scope: Support structures for all auxiliary navigation equipment within the runway obstacle restriction area.
Fragile and brittle items—objects that may break (shatter), bend, or yield under specified impact forces, thereby posing a lesser hazard to aircraft as lightweight objects.
Fragility
Visual and non-visual navigation facilities at airports, such as approach lighting towers, meteorological equipment, and radio navigation equipment, are typically located near runways, taxiways, and aprons. Failure to avoid collisions with these facilities during takeoff or landing can pose a hazard. All such equipment and their supports must be collapsible and installed as low as possible to prevent collisions from causing aircraft control loss. Collapsibility can be achieved through various design concepts, such as using lightweight, easily collapsible, and brittle materials, components with low toughness, and joints, ensuring that collapsible objects shatter, bend, or yield upon impact.
Flexible and fragile pole structures (hereinafter referred to as "flexible poles") are support structures made in single-pole and tower configurations, utilizing lightweight, fragile materials and a design prone to bending.
Condition for bendability of aviation easily broken and fragile rods
For aircraft that may not be capable of flying or gliding to a landing, the breakaway rods must be breakable and shatterable upon impact by an aircraft weighing 3,000 kg and traveling at 140 km/h. For aircraft that may not be capable of ground sliding, the breakaway rods must also be breakable and shatterable upon impact by an aircraft weighing 3,000 kg and traveling at 50 km/h. The force exerted by the breakaway rod on the aircraft during impact must not exceed 45 KN; the energy transferred to the aircraft by the breakaway rod must not exceed 55 KJ.