What is Aircraft ULD in Air Transport?

What is Aircraft ULD in Air Transport?

If you’re shipping air freight, your main concern is getting the freight where it needs to be, and fast. When you ship cargo by air, you’re most likely using a ULD (Unit Load Device), but what is it? An aircraft ULD is a piece of equipment used to group and restrain cargo, mail, and baggage for air shipment. It can be either an aircraft container or a combination of an aircraft pallet and an aircraft pallet net.

In this article we’ll answer some basic questions about what goes on behind the scenes as air cargo moves from your dock to your customer.

What is a ULD?

Building Airline ULDA unit loading device (ULD) is the air freight equivalent of the ocean container. It allows for the safe, fast, efficient transit of freight on passenger and cargo aircraft. A steamship line can put upwards of 20,000 stacked containers on one vessel. With airplanes, it’s a different story. Loading spaces are small and irregularly shaped. That’s why there are many different ULDs, in different sizes and shapes, to make the best use of the available space.

There are two basic types of ULD: a closed metal container that houses freight inside and a metal pallet onto which cargo can be loaded. Cargo on pallets is covered with a net and secured under the ULD. Whether you’re moving pallets of merchandise or cars or expensive equipment, ULDs are secured to the body of the aircraft to keep the freight from shifting, even during the most turbulent flights.

Air cargo can be tendered to the carrier either loose or already containerized. Once loose freight is checked in, it is loaded by the carrier into a ULD.

Why Airlines Need ULDs？

Fast global shipping means air freight. Every 24 hours, more than 140,000 tons of cargo are transported, equivalent to 657 million packages worth $17.8 billion. To transport this much air cargo, a large number of aircraft ULDs are needed to safely deliver the cargo from one destination to another. Many multinational companies utilize air freight and unit load equipment to move perishable items such as fruits and vegetables, seafood, flowers, time and temperature sensitive healthcare products such as vaccines and other pharmaceuticals, not to mention air mail services provided by postal operators around the world for letters and express parcels, and many more items that need to be delivered quickly and safely.

What types of ULD equipment do airlines have?

1. Air Freight Containers

Containers are closed equipment used to carry cargo or luggage. Containers come in different sizes and shapes depending on the type of aircraft and airline requirements. Common container types include:

● LD3 (or ULD Type A): A common wide-body aircraft container, typically measuring 1.53m x 1.57m x 1.63m (length x width x height). This container is mainly used on aircraft such as Boeing 747 and Airbus A330.

● LD6 (or ULD Type D): A larger container, measuring 2.13m x 1.58m x 1.53m. Usually used on Boeing 767 or similar aircraft.

● LD7 (or ULD Type G): Used on larger aircraft such as Airbus A380. The dimensions are 2.47m x 1.58m x 1.53m.

● LD9 (or ULD Type P): For large aircraft or wide-body aircraft, the dimensions are 2.51m x 1.58m x 1.53m.

2. Aircraft Pallets

Pallets are open ULD devices, and the cargo is placed directly on the pallet, usually fixed by straps, grids or other fixings. Common pallet types include:

● P1P (or Type 1): The standard size is 2.44m x 2.44m, suitable for large aircraft such as Boeing 747 and Airbus A300.

● P2P (or Type 2): A smaller pallet with a size of 2.44m x 1.88m. This pallet is usually used in smaller aircraft or cabin areas.

● AAY (or Type A): The size is 2.19m x 2.44m, suitable for multiple models, especially some models of Airbus and Boeing.

When would you use a container or a pallet?

Airline Containers have the following advantages:

● Make loading and unloading faster and easier

● Protect against any kind of weather – do not require the extra wrapping that you’d want for the palleted cargo

● Protect better against damage ­– no need for corner guards or other special protective packaging

● Prevent unauthorized access to the cargo

When to 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

ULD pallets, sometimes referred to in the industry as “cookie sheets,” are cheaper to use than containers. Other advantages:

● Accept oversized cargo that won’t fit in a container

● Take up less room than containers since they are flat and can be stored efficiently and returned by plane

● Have more options for how to build the pallet (size and shape) depending on where on the plane the airline ULD pallet is being loaded

When to use a airline 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 pallets

- Stackable: efficient and easy to store and return

As a shipper, the choice of ULD is typically made for you, by the airline or your freight forwarder. It’s a little different if you’re shipping temperature-sensitive cargo. You’ll want a specialized, temperature-controlled airline ULD.

What factors should you consider when choosing an ULD?

Aircraft Containers are ideal for high-value or sensitive cargo, while pallets are suitable for oversized or bulk items. AirlineContainers offer better protection for long-distance shipments, while pallets may be more cost-effective for shorter distances.

Temperature-sensitive cargo may require specialized containers or ULDs with temperature-controlled features.

How to Load / Unload of Aircraft Containers

1.Always check the unit before starting loading. Any damage found must be below the required damage limits otherwise the ULD is not airworthy.

2.Cargo or bags should be stacked in an interlocking fashion as far as possible.

3.Avoid placing heavy cargo in the outboard section of the container (overhanging section) as this can cause the container to rock or tilt to the outside, causing loading difficulties.

4.Ensure that cargo/ baggage in the door side does not extend to the point that the door is not flat when closed.

5.Inspect the loaded ULD to ensure it is within the designated contour. It may appear that a container is within its contour by the nature of its structure, however there are extremely small clearances between the container and the cargo hold liner in many aircraft and even a small distortion in the container structure (as may occur due to certain types of damage, or from loading heavy cargo in the overhanging section of the container) can result in the container touching the hold walls, causing considerable damage and grounding the aircraft (hold liners are fire containment devices and if punctured the aircraft cannot take off). Care must be taken that all ULD are within their designated contour before they are loaded to the aircraft.

6.Consult airline guidance for any heavy items which may require spreader boards to spread the weight on the base and may require additional tie down using cargo straps.

7.When closing the door, do not use hammers or other excessive force to operate latches etc as these will almost certainly not be openable on arrival at destination.

8.Never use knives to cut open a container door

How to Load/unload of Aircraft Pallets/nets

1.Before loading begins, perform a pre-loading inspection to determine if the pallet and nets are serviceable. Particular attention should be paid to cargo nets used to secure cargo to the pallet. Cargo nets are subject to severe wear and tear and are often unusable. It is important to determine if the nets are serviceable before loading the pallet.

2.Load cargo in an interlocking manner whenever possible. Ensure that the cargo is within the specified profile. Overhang cargo (for lower deck cargo) must be constructed in such a way that the overhang will not collapse in flight.

After all cargo is loaded, the net should be used as follows:

● Place the net over the load and attach the net accessories to the seat rails evenly spaced along both sides

● Use the "reefing hooks" on each side to retract excess net (found in non-full profile loads)

● Close and gently tighten the net using corner ropes (lashing wires) or other suitable corner closure devices.

Note: While it is generally accepted in the industry that nets need to be as tight as possible, this is incorrect. Neither manufacturers, aviation safety agencies nor IATA have made such a requirement. The correct approach is for the net to be tight but not too tight. The purpose of the net is to limit forces during flight, and it performs this function perfectly when installed without tension.

1. Over-tightening the net can not only damage the cargo, but can also pull up the pallet edge rails, making it difficult or impossible to lock the pallet to the aircraft.

2. Freight often needs to travel considerable distances by road to the nearest airport, so it has become common practice to use cargo nets as "fixtures" to secure cargo during road transport. The design of the cargo net (diamond mesh) is not suitable for this purpose.

3. Never use a knife to cut the net. This will damage an expensive airline asset and render the net unusable.

How to Identify ULDs by Code

Each aircraft unit load device (ULD) is identified by its ULD code. This code is a unique combination of letters and numbers that begins with a three-letter prefix that identifies the type of ULD. This prefix is followed by a unique 4- or 5-digit serial number to distinguish it from other devices of the same type. The last two or three characters indicate the owner of the ULD.

How do airline ULDs and ULD manufacturers affect your ability to ensure reliable air freight capacity?

Passenger airlines often overbook and then have to ask some passengers to get off the plane and take a later flight. The same is true for air cargo! Especially in the current market where cargo capacity is limited. If you work with a freight forwarder that has a Bulk Service Agreement (BSA) with the airline, your cargo is less likely to be unloaded. Large freight forwarders essentially pre-purchase cargo space from airlines before they have customers. These BSAs correspond to a certain amount of cargo (metric tons) on a specific route at a specific time. Most of the committed tonnage is usually achieved through fully assembled ULDs. So if your cargo is transported by a freight forwarder who assembles the ULDs and gives them to the airline, the space is fixed. On the other hand, if the cargo is given to the airline in bulk, the airline assembles the ULDs, mixing your cargo with that of other freight forwarders. In this case, the airline is not obligated to transport this cargo on a specific flight as part of any existing BSA. So if the carrier accepts more cargo than it can carry, it can unload your cargo.

Cheerong Aircraft Container & Aircraft Pallet

Airfreight Containers (ULD) is a type of pallet or container used to store bulk cargo for transport by air. If you have any questions or would like to know more about our Airfreight Containers (ULDs) and airfreight pallets? Please contact us or click on this page https://www.aircheerong.com/aircraft-container to learn more.