ISO DIS 21894

Description / Abstract: This International Standard 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 International Standard 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 7.4 in ISO 16049-2, Cargo Restraint Straps – Utilization Guidelines.

(b) to restrain cargo smaller than the pallet net’s mesh, or identified as “piercing”, 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 may contain a heavy item, e.g. 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.

Cargo Stopper devices are used as part of cargo restraint arrangements that must meet the regulatory airworthiness requirements. Accordingly, their design and performance must be substantiated as specified in this International Standard in order to meet regulatory requirements and obtain TSO-C202 approval.