What's a ULD?
A Unit Load Device (ULD) is used to transport cargo by aeroplane. ULDs can convey any type of cargo, from passenger suitcases and perishable goods to horses and Formula-1 cars. ULDs are divided into two main categories: aircraft containers and aircraft pallet/net combinations.
Crucial role in air cargo transportation
ULDs are crucial in transporting air cargo safely, quickly and cost-effectively. They enable individual pieces of cargo, luggage or mail to be assembled into a single unit, which can then be loaded on and off an aircraft with speed.
To prevent the ULDs moving around during flight and potentially damaging the aircraft, the plane has loading and restraint systems. These interface directly with a ULD, effectively locking the ULD into place so it becomes part of the aircraft.
The benefits of ULDs
The most important purpose of a ULD is to secure cargo during flight. The safety of the plane and its passengers comes first every time. But ULDs also:
- eliminate the need for manual loading and unloading
- protect cargo contents so that goods arrived undamaged
- maximise the use of the aircraft’s cargo space
- allow the fast, easy transfer of cargo between planes
The global introduction of standardised containers has improved cargo handling enormously, lowering operational costs. That, in turn, helps lower freight charges and boosts trade flows.
Regulating ULDs to ensure flight safety
Just like any other aircraft component, ULDs are regulated to ensure flight safety under all likely and extreme circumstances. These rules are defined by the International Civil Aviation Organization (ICAO) and put into national legislation by each Civil Aviation Authority (CAA). The CAA assesses and certifies ULDs for their continued airworthiness.
Both pallets and containers allow a large quantity of cargo to be bundled into a single unit, which can be used on wide-body aircraft and certain narrow-body aircraft.
Cargo on pallets are secured by a net, which is attached to the pallet’s rim. Containers, also known as cans and pods, are typically lightweight structures comprising a base, a frame with side and roof panels, and a fabric or solid door. There are many different types of containers. Some are collapsible, some are insulated, others are ventilated or refrigerated and so on.
Why use a container?
- Makes loading and unloading cargo easier
- Makes loading onto and unloading off an aircraft easier
- Gives better protection against all kinds of weather
- Gives better protection against damage to the cargo
- Gives better protection against damage to the aircraft by the cargo
- Prevents unauthorised access to the cargo
Why use a pallet/net?
- Cheaper to use than containers
- Accepts cargo that is difficult to fit into containers (e.g. oversized cargo)
- Accepts some ‘Special Load’ cargo that can only be loaded on open pallets
- They are stackable and therefore efficient and easy to store empty and return by plane