Unit Load Device,

When you ship goods by air you are most likely using a ULD (Unit Load Device), but what is that? An aircraft ULD is a device for grouping and restraining cargo, mail and baggage for air transport. It is either an aircraft container or a combination of an aircraft pallet and an aircraft pallet net. Aircraft ULD is designed to be directly restrained by the aircraft Cargo Loading System (CLS). And because the aircraft CLS directly interfaces with the aircraft ULD, the unit load device becomes part of the aircraft’s structure during flight and is therefore regulated, as any other aircraft component, in order to ensure flight safety under all foreseeable circumstances. The design, testing, manufacturing, operations as well as maintenance and repair of the unit load device are all subject to the safety and airworthiness requirements from the civil aviation authorities.

ULD container build-up is considered aircraft pre-loading, therefore, one of the main purposes of using aircraft ULD is to allow consignments to be unitized and grouped at the cargo warehouse hence eliminate greatly the manual loading and unloading of aircraft. The use of unit load devices also effectively protects the contents loaded from loss and damage. The design of the aircraft ULD contours maximizes the use of aircraft contours. The use of unit load devices facilitates fast and easy transfer of the ULD and the contents loaded from one aircraft to another and even from one mode of transport to another.

However, the most important purpose of unit load devices is to secure the loads throughout the flight from take-off to landing and especially during turbulence, which is similar to the purpose of the passenger seat belt. If the loads were not secured and restrained during flight, not only would they damage the aircraft but also the load shifting might impact the aircraft weight and balance and hence cause the loss of control of the aircraft.