Airport foldable and fragile pole application scope: Support structures for all aids to 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 less harm to aircraft as lighter-weight objects.
Fragility
Various visual and non-visual navigation facilities at airports (such as approach lighting towers, meteorological equipment, radio navigation equipment, etc.) are typically located near runways, taxiways, and aprons. If an aircraft taking off or landing collides with them unexpectedly, it poses a danger. All such equipment and their supports must be breakaway and installed as low as possible to ensure that a collision does not lead to aircraft control loss. Breakaway capability can be achieved through various design concepts, such as using lightweight, breakable, and brittle materials, components, and fasteners with low toughness, 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-like, and other configurations, utilizing lightweight, fragile materials and fragile structures.
Condition for bendability of aviation easily breakable and fragile rods
Collapsible rods must easily bend and break upon impact by an aircraft weighing 3,000 kg and traveling at 140 km/h for aircraft that may not take off or land. For aircraft that may not glide on the ground, the rods must also bend and break upon impact by an aircraft weighing 3,000 kg and traveling at 50 km/h. The force exerted by the collapsible rod on the aircraft during impact should not exceed 45 KN; the energy transferred to the aircraft by the rod should not be more than 55 KJ.