Air Cargo Pallet Dimensions & ULD Sizes: PMC, PAG, LD3

A unit load device (ULD) is either an aircraft pallet with its pallet net, or an aircraft container. Air cargo usually isn’t loaded into the hold box by box: it’s built onto these units first, and the aircraft loads the units. That’s why air cargo pallet dimensions are fixed standards.

ULDs count as removable aircraft parts. Civil aviation authorities regulate them at every stage, from design and testing to manufacture, operation and maintenance. The technical and operating standards sit in the IATA ULD Regulations (ULDR), which draw on IATA, ISO and SAE standards, and the IATA ULD Board maintains the specifications and handling rules. IATA puts the number of ULDs in service at about 1 million.

There are two families. Pallets are flat and can be built high around bulky cargo. Containers are closed and shaped to the hold, which protects the cargo but costs some space. This guide covers the air freight dimensions that matter for each: base sizes, weight limits, the height limits for the lower deck (the hold under the passenger cabin) and the main deck of a freighter (an all-cargo aircraft), how ULD rates work when a freight forwarder builds the unit, and how to read a ULD code.

Air cargo pallet dimensions#

An aircraft pallet is a flat plate with a seat track (a locking rail) around the edge. Cargo is stacked on the plate, wrapped, and secured with a rated pallet net. It’s usually aluminum. The pallet itself is aircraft equipment registered to an airline, and it goes back to the airline after the flight.

That makes an air pallet a very different thing from the wooden pallets used in warehouses and trucks. For those, see our guide to standard pallet sizes.

The airline pallet sizes you’ll see most often:

The maximum gross weights are nominal figures. Vietnam Airlines lists 6,800 kg for both the PMC and the PAG, while Thai Cargo lists 6,804 kg for the PMC and 6,033 kg for the PAG. Thai Cargo gives 13,608 kg for the PGA on freighters such as the 74F, and a UK forwarder quotes 11,340 kg and 33 m³ for a comparable 20 ft unit. What a pallet can actually carry depends on the aircraft type and the loading position under the airline’s weight and balance manual, so confirm the limit with the airline when you book.

Tare weight matters too. A PMC weighs about 120 kg with its net, and a PAG weighs 96–115 kg.

Air cargo containers: AKE (LD3) and others#

A container is a closed ULD. Most have a sloped side, called the contour, that follows the curve of the fuselage in the lower hold.

The standard belly container (for cargo carried in the lower hold of a passenger aircraft) is the AKE, often called the LD3. The two names refer to the same unit: LD3 comes from the ATA system (now Airlines for America), and AKE is the IATA ULD code. It’s a half-width container, so two sit side by side across the lower deck. The door is either canvas or solid. AirBridgeCargo lists its door opening as 58 × 61 in (147 × 155 cm); American Airlines Cargo gives 58 × 56 in.

A few notes on the table:

• AKE. The base is 61.5 × 60.4 in and the height 64 in. Across the sloped side it measures 79 in (200.7 cm). Vietnam Airlines and AirBridgeCargo list 4.5 m³; Thai Cargo lists 4.3 m³ and American Airlines Cargo 4.32 m³ (3,500 lbs / 1,587 kg max gross). It fits the lower deck of most widebody aircraft (twin-aisle jets): Vietnam Airlines names the B777, B787, A350 and A330, American Airlines Cargo the 787 and 777, and Thai Cargo the 747, 777, A330 and A340, among others.
• AKH. Same base as the AKE but only 45 in (114.3 cm) high, for the lower hold of narrowbody (single-aisle) A320-family aircraft. Vietnam Airlines lists 3.6 m³ and 1,587 kg, cut to 1,134 kg on the A321; other sources give 3.7 m³.
• AAP. 125 × 88 × 64 in, so it’s a container built on a PAG base. Airlines don’t all use “LD” names the same way: American Airlines Cargo’s “LD9” is a 125 × 96 in unit rated at 5,034 kg.
• AMA. A box-shaped main deck container on a PMC (P6P) base, for freighters. The 243.8 cm height is read from AirBridgeCargo’s drawing; we haven’t found a published volume.

The contour costs space. The outer box around an AKE is 200.7 × 153.4 × 162.6 cm, which works out to about 5.0 m³ (2.007 × 1.534 × 1.626 m). The internal volume airlines publish is only 4.3–4.5 m³.

Height limits by aircraft deck#

Two ULDs with the same base can be built to very different heights. The limit comes from where the unit is loaded, not from the pallet itself.

• Lower deck. In the belly of a passenger aircraft, pallets are built to a 64 in (162.6 cm) contour. AirBridgeCargo and Vietnam Airlines both give 11.5 m³ of usable volume for a PMC built this way; Vietnam Airlines gives 10.5 m³ for a PAG. Forwarders usually tell shippers to keep cargo to about 160 cm including the pallet base.
• Freighter main deck. The standard main deck contour is 96 in (243.8 cm), which gives a PMC 17.0 m³.
• Higher main deck positions. Some freighter positions take a 118 in (299.7 cm) contour, or 21.2 m³ on a PMC. Which positions allow this depends on the aircraft; the center section of a 747F is a commonly cited example, but check with the airline.

The line that matters is the lower deck. Cargo taller than about 163 cm won’t fit a passenger aircraft’s lower-deck ULD, however light it is. That leaves freighters only, which usually means fewer flights to choose from and can mean a higher rate. If your cargo is close to this height, measuring it accurately before booking is worth the effort.

Who builds the ULD: BUP and ULD rates#

The airline doesn’t always build its own ULDs. Under IATA’s bulk unitization program (BUP), the airline hands out empty ULDs, the cargo is built up (loaded and netted onto the ULD) outside the airline, usually in a freight forwarder’s warehouse, and the finished unit is delivered to the airline ready to fly. The industry calls this a “shipper-built ULD,” but in practice the builder is usually the forwarder, not the cargo owner. IATA publishes quality and standards guidance for BUP builds.

A unit built at the forwarder’s warehouse gets handled fewer times on the way. According to one Japanese forwarder, that shortens lead time, reduces damage and improves security.

The airline then charges a rate per ULD instead of a per-kilogram rate on each shipment. Korean Air’s tariff calls this the Bulk Unitization Charge (BUC):

• Each ULD type has a minimum charge.
• The minimum charge covers weight up to a pivot weight, the most the ULD can carry at that minimum.
• Weight above the pivot weight is billed as an over-pivot charge.

The weight that counts is the cargo, not the ULD. For an airline-owned ULD, it’s the actual gross weight minus the ULD’s tare weight. For a shipper-owned ULD, the deduction is the tare allowance or the actual tare, whichever is lower. Dangerous goods, live animals, human remains and valuables are excluded from BUC rates.

This is where a consolidator (the forwarder that combines several shippers’ cargo) makes its margin. The forwarder pays the airline per ULD, but bills each shipper on chargeable weight: the actual weight or the volumetric weight, whichever is greater. Volumetric weight (dimensional weight in US usage) is length × width × height in cm ÷ 6,000. You can work out that figure with our chargeable weight calculator. The gap between what the forwarder pays per ULD and what it bills per shipment is its consolidation margin, which gives forwarders a reason to fill each ULD right up to its contour and height limit.

Planning a load onto a ULD#

A first check is whether your cargo fits the base and height at all. For a PMC in the lower deck, you’re working with a 243.8 × 317.5 cm base, a 162.6 cm contour and 11.5 m³ of usable volume. On a container, remember the contour takes some of the space inside the outer box.

Box sizes that divide the base cleanly waste less. The long side of a PMC or PAG is 125 in, or 317.5 cm, and 25 in (63.5 cm) boxes fit along it exactly five times. Any empty strip left around the edge is space you pay for under a per-ULD rate. For more on laying out boxes, see how many boxes fit on a pallet.

The ideal build runs out of usable volume at the same moment it reaches the pivot weight. To find the density that does this, divide the target weight by the usable volume. Load lighter than that and the ULD fills up before it reaches the weight limit; load heavier and you hit the weight first with space left over.

Light cargo fills a ULD long before it gets heavy. Air freight’s volumetric rule works out to 166.67 kg per cubic meter, the density at which volumetric and actual weight are equal. Fill the 11.5 m³ of a lower-deck PMC with light goods and the shipments on it are charged on about 1,917 kg of volumetric weight in total (11.5 × 166.67), however little the cargo actually weighs.

To get the total volume and weight of your cargo, use the CBM calculator. It gives total cubic meters, total kilograms and air volumetric weight, which you can then compare with the usable volume and the weight limit of the ULD you’re aiming for.

How to read a ULD ID code#

Every ULD carries a ULD ID code of 10 characters:

• a 3-letter type code
• a serial number, usually 5 digits (4 on older units)
• a 2-character owner code assigned by IATA

For example, PMC 45231 KE is a PMC pallet with serial number 45231 and owner code KE.

The three type letters each mean something:

• First letter: category. A is a certified container, P a certified pallet, D a non-certified container and R a certified thermal (temperature-controlled) container. IATA defines 17 categories in all.
• Second letter: base size. The same 15 letters apply to containers and pallets. M is 96 × 125 in (PMC), A is 88 × 125 in (PAG), K is 61.5 × 60.4 in (AKE, AKH), L is 60.4 × 125 in (PLA) and G is 96 × 238.5 in (PGA).
• Third letter. On a container, it gives the IATA contour, which matches the shape of a particular hold. Loading a container with the wrong contour puts the aircraft at risk. On a pallet, it gives the certification type.

So in PMC, P says pallet and M says 96 × 125 in. In AKE, A says container and K says the 61.5 × 60.4 in base. Once you know PMC, PAG, PLA, AKE and AKH, you can read the codes that come up most often on air waybills.