Air cargo containers, which are also called Unit Load Devices, air containers, airplane cargo containers, air freight containers or ULDs, come in two main forms: rigid, enclosed containers and pallet/net combinations.
Pallets, due to their low profile, flat structure and relative strength, are used to either carry cargo (in which case the cargo must be secured to the pallet using a net and tension straps) or support a container. However, not all containers use pallets as a base because they can add weight and reduce volume.
These days, most air freight containers are constructed using sheet aluminium or polycarbonate with profile frames. They also come in standardized dimensions to make it possible to load them into the hold of an aircraft. Even so, exact dimensions and weight limitations vary by manufacturer, and customisation can be an option.
Whichever form they come in, the purpose of air freight containers is the same: to enable the transportation of cargo by air safely, quickly and cost-effectively. What’s more, there’s almost no limit to the type of cargo they can carry, from express mail and delicate technical equipment to pharmaceuticals and horses.
Air freight pallets are not your standard wooden warehouse pallets. They must meet stringent safety standards and be capable of being secured by the aircraft’s Cargo Loading System.