Airport foldable and fragile pole application scope: The supporting structures for all aids to navigation equipment within the runway obstruction area.
Fragile and brittle items—objects that may fracture (break), bend, or yield under specified impact forces, thereby posing a lesser risk to aircraft as lighter-weight objects.
Crippliness
Visual and non-visual navigation facilities at airports (such as approach lighting towers, meteorological equipment, and radio navigation equipment, etc.) are generally located near runways, taxiways, and aprons. If an aircraft taking off or landing collides with them unexpectedly, it could pose a danger. All such equipment and their supports must be breakaway and installed as low as possible to ensure that a collision will not lead to aircraft control loss. Breakaway capability can be achieved through various design concepts, such as using lightweight, easily breakable and fragile materials, brittle and low-toughness components and fasteners, to ensure that breakaway objects shatter, bend, or yield upon impact.
Flexible and fragile poles (hereinafter referred to as "flexible poles") are support structures made in single-pole, tower-type, and other configurations, utilizing lightweight fragile materials and a design prone to bending.
Condition for bendability of aviation easily breakable and fragile rods
For aircraft parts that may not withstand a hard landing, the bendable rods must bend and break upon impact by an aircraft weighing 3,000 kg and traveling at 140 km/h. For aircraft parts that may not slide on the ground during a collision, the bendable rods must bend and break upon impact by an aircraft weighing 3,000 kg and traveling at 50 km/h. The force exerted by the bendable rod on the aircraft during impact should not exceed 45 KN; the energy transferred to the aircraft by the bendable rod should not exceed 55 KJ.