本文件规定了额定载荷能力为22 250 N（5 000 lbf）的“货物限位器”空运货物约束附件的设计、性能和测试要求，这些附件将与符合ISO 16049-1（TSO/ETSO？C172）的空运货物约束带或符合ISO 20291-1的空运货物约束吊索一起使用，并具有相同的额定载荷。 根据本文件设计的货物止动装置适用于以下任一典型情况: a） 确保对货物进行约束/系紧，使其不会直接钩住系紧带或在不存在滑脱风险的情况下绕过系紧带； 一个常见的例子是具有窄横截面的长形货物，无论是否从托盘上伸出，单个或成捆，例如管道或横梁；参见ISO 16049-2:2020，7.4； b） 限制小于托盘网网眼的货物，或被确定为“穿孔”货物，如果在飞行过程中释放，会对飞机造成危险； c） 当装有货物的板条箱，即使其横截面足够大，可以用托盘网或约束带直接系紧，但包含或可以包含带有横截面的重型物品，例如机械、轴或类似物品时- 截面低于托盘网的网目尺寸； 注:已知此类“隐藏”物品在受到飞行加速度时会从强度不足的板条箱中挣脱出来，然后由于其尺寸较小而通过约束板条箱的网状物，并释放到货舱中。 d） 在难以或不允许直接连接系紧带或以有效方式将其绕过货物的情况下，协助系紧异形货物。

This document specifies the design, performance and testing requirements for "Cargo Stopper" air cargo restraint accessories with a 22 250 N (5 000 lbf) rated load capacity, to be used in conjunction with air cargo restraint straps meeting ISO 16049-1 (TSO/ETSO？C172), or air cargo restraint slings meeting ISO 20291-1, with the same rated load. Cargo stopper devices designed to this document are intended to be used in either of the following typical instances: a) to ensure restraint/tie-down of a piece of cargo that does not lend itself to either direct hooking of tie-down straps or passing a strap around without risk of slippage; a common example is long shaped cargo items with a narrow cross-section, whether or not overhanging from the pallet, individual or in bundles, e.g. pipes or beams; see ISO 16049-2:2020, 7.4; b) to restrain cargo smaller than the pallet net's mesh, or identified as "piercing" cargo, presenting a hazard to the aircraft in the event of it being released during flight; c) when a crate containing cargo, even though its cross-section is large enough to be directly tied-down with the pallet net or restraint straps, contains or can contain a heavy item, e.g. a piece of machinery, shaft, or similar, with a cross-section lower than the pallet net's mesh size; NOTE Such "hidden" items have been known to break free from insufficiently strong crates when subjected to in-flight accelerations, then pass due to their small size through the net mesh restraining the crate and be released into the cargo compartment. d) to assist in tying-down odd-shaped cargo pieces where it is difficult or not allowed to directly attach tie-down straps or pass them around the load in an effective manner.