在机场，各种视觉和非视觉辅助设备位于跑道、滑行道和停机坪附近，如果在着陆、起飞或地面操纵过程中发生意外碰撞，它们可能会对飞机造成危险。所有此类设备及其支架应易碎，安装位置应尽可能低，以确保撞击不会导致飞机失控。本手册提供了机场和直升机场脆弱结构的设计、测试和安装指南。许多材料与视觉和非视觉材料的脆弱性规范密切相关- 附件14第1卷和第2卷中包含的视觉教具。

At airports, various visual and non-visual aids are located near runways, taxiways and aprons where they may present a hazard to aircraft in the event of accidental impact during landing, take-off or ground manoeuvring. All such equipment and their supports shall be frangible and mounted as low as possible to ensure that impact will not result in loss of control of the aircraft. This manual provides guidance on the design, testing and installation of frangible structures at airports and heliports. Much of the material is closely associated with the specifications on frangibility of visual and non-visual aids contained in Annex 14, Volume 1 and 2.