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What is a ULD (unit load device)?

June 14, 2026 — Lê Văn Thăng

What a ULD is: the air-cargo container and aircraft pallet. The IATA ID code (e.g. AKE), flight-safety role, types and how it differs from a normal pallet.

Reviewed and updated by ICD - Week 24/2026

A ULD (Unit Load Device) is an air-cargo loading device - an aircraft container or a combination of aircraft pallet and net - used to group and restrain cargo, mail and baggage. A ULD fits the aircraft’s cargo loading system (CLS) and hold contour precisely; in flight it becomes part of the aircraft structure, so it must meet strict safety standards like any aircraft component.

The role of a ULD

A ULD turns many loose packages into one standardised unit load, speeding aircraft loading/unloading, using hold space and restraining cargo in flight. This is the unit-load concept applied to aviation. A ULD with the wrong contour or damage can compromise flight safety and damage the aircraft - the industry spends about USD 400 million a year on ULD repair and loss.

ULD identification code (IATA)

Each ULD has a 9-10 character IATA code: the first 3 letters are the Type Code, the next 4-5 are the serial number, and the last 2 are the owner (airline) code. For example AKE: A = certified container, K = base dimensions 1,534×1,562 mm, E = contour. The first character gives the category (A = certified container, P = certified pallet); the third is critical because the contour must match the aircraft hold.

Types of ULD

Type Characteristics
Aircraft container (e.g. AKE/LD3) Enclosed container, hold-contour shaped, most common
Aircraft pallet + net Aluminium pallet + restraint net, for bulky cargo
Special-purpose ULD Temperature-controlled, fire-resistant, horse stalls (HMA/HMJ)…

Note: codes LD3, LD7 (old ATA system) and AKE (IATA system) often describe the same device - the IATA system is now more widely used.

ULD vs a normal pallet

Criterion Aircraft ULD Normal pallet (road/sea)
Standard IATA, airworthiness certified ISO/regional, no flight certification
Shape Matches aircraft hold contour Flat, standard rectangle
Material Aluminium, light composite Wood, plastic

The ULD is an aviation-specific concept; in road and sea transport the standard load unit is the pallet and bin/crate - ICD supplies wooden pallets, plastic pallets and plastic crates for ground unit loads.

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Frequently asked questions

What is a ULD?

An air-cargo loading device (Unit Load Device) - an aircraft container or aircraft pallet with net - used to group and restrain cargo, mail and baggage.

What does the code AKE mean?

An IATA ULD Type Code: A = certified container, K = base dimensions 1,534×1,562 mm, E = the contour matching the aircraft hold.

Are LD3 and AKE different?

They usually describe the same device: LD3 in the old ATA code system, AKE in the current IATA system - IATA is now more widely used.

How does a ULD differ from a normal pallet?

A ULD is IATA-certified, shaped to the aircraft hold contour, in aluminium/composite; a normal pallet is flat, ISO-based, for road and sea.

Why must a ULD meet flight-safety standards?

Because in flight the ULD becomes part of the aircraft structure; a wrong contour or damage can compromise flight safety and damage the aircraft.

What types of ULD are there?

Aircraft containers (e.g. AKE), aircraft pallets with restraint nets, and special-purpose ULDs (temperature-controlled, fire-resistant, livestock…).

Contact ICD Vietnam

ICD Vietnam Industrial Manufacturing Co., Ltd - pallets, plastic crates, stretch film, forklifts and packaging solutions.

Hotline: 0983 797 186 / 090 345 9186
Email: sales@icdvietnam.com.vn | Zalo: Chat on Zalo


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