"Purpose The purpose of this SAE Aerospace Standard (AS) is to standardize the basic design@ performance@ and testing requirements for ""Cargo Stoppers"" cargo tie-down accessories to be used in conjunction with approved restraint straps meeting AS5385C (TSO C-172) requirements. The lack of an agreed industry standard resulted in uncertainties about their operational capabilities@ so that it was deemed advisable to specify the applicable design@ minimum performance and testing requirements@ since Cargo Stoppers are used as part of cargo tie-down arrangements that must meet regulatory airworthiness requirements. Field of Application The Cargo Stopper devices specified by this Aerospace Standard (AS) are intended to be used in either of the operational circumstances defined in 1.2.2@ 1.2.3 and 1.2.4 hereafter. A Cargo Stopper device should be used to ensure restraint/tie-down of a piece of cargo that does not lend itself to either direct hooking of restraint straps or passing a strap around without risk of slippage. A common example is long cargo items with a narrow cross-section@ whether or not overhanging from the pallet@ individual or in bundles@ e.g.@ pipes or beams. See 6.4 in ARP5595. A Cargo Stopper device shall be used to restrain cargo identified as ""piercing""@ presenting a hazard to the aircraft in the event of it being released during flight. A Cargo Stopper device shall also be used whenever 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.@ 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. In addition@ a Cargo Stopper device may also be used to assist in tying-down odd shaped cargo pieces where it is difficult or not allowed to directly attach restraint straps or pass them around the load in an effective manner."