Air freight has its own vocabulary, and most confusion comes from a handful of concepts that are rarely explained well. If you understand these eight, you will read quotes more confidently, ask sharper questions and spot problems before they cost you money.
01Belly cargo and freighters
Most air cargo does not fly on dedicated freight aircraft. It travels in the lower deck, or belly, of passenger jets, underneath the cabin. On long-haul routes out of Australia, a single widebody passenger aircraft can carry many tonnes of freight alongside baggage.
Freighters carry cargo on the main deck as well, which allows larger and heavier pieces and some dangerous goods that cannot travel on passenger flights. Integrated express carriers and airlines such as Qantas Freight operate freighter networks, while forwarders buy space on both types. When a route loses passenger flights, cargo capacity disappears with them, which is why international border closures in 2020 hit Australian exporters so hard.
02Chargeable weight
Airlines sell space as well as lift, so they charge on whichever is greater: the actual weight or the volumetric weight. For standard air cargo, volumetric weight is length × width × height in centimetres divided by 6,000, which treats one cubic metre as 167 kilograms. Express carriers often divide by 5,000.
This single rule explains most surprises on air freight invoices. Oversized cartons, loose void fill and poorly stacked pallets all add volume you pay for, even though the goods themselves are light.
03The air waybill
The air waybill, or AWB, is the contract of carriage between the shipper and the airline and the key reference for tracking. It is not a document of title, so unlike an ocean bill of lading, it cannot be traded to transfer ownership of the goods.
Each master AWB has an eleven-digit number, and the first three digits identify the airline. When a forwarder consolidates several customers' cargo, each customer receives a house air waybill under the master. Electronic air waybills have now largely replaced paper on major routes.
04ULDs and build-up
Cargo on widebody aircraft is loaded into unit load devices, known as ULDs. These are aluminium containers and pallets shaped to fit the curve of the fuselage. Ground handlers build cargo up onto ULDs before the flight and break it down on arrival.
Shape matters. Cargo that is too tall, too heavy for its footprint or awkwardly shaped may not fit certain aircraft or may need a freighter. Stackable, well-wrapped cartons build up efficiently, which helps cargo make its planned flight.
05Security screening
All air cargo must be secure before it is loaded. In Australia, this is managed under the aviation security framework through regulated air cargo agents, who screen cargo or receive it from known consignors whose premises and processes have been approved.
For shippers, the practical effect is that cargo from an approved secure supply chain can move faster, while unknown cargo needs screening by x-ray, explosive trace detection or other methods before acceptance. Screening fees usually appear on origin charges.
06Customs and biosecurity
Every international shipment entering Australia is reported to the Australian Border Force before arrival. Goods valued above AUD 1,000 need a full import declaration, with duty, GST and charges paid before release, while lower-value goods usually move through a simplified self-assessed process.
Biosecurity runs alongside customs and applies to every consignment. Timber packaging, food, plant material and used equipment are the usual triggers for inspection. On the export side, an Export Declaration is required for goods over AUD 2,000 or goods that need a permit.
07Incoterms
Incoterms are the internationally recognised rules that divide costs and risk between buyer and seller. For air freight, FCA, CPT, DAP and DDP are the most useful. FOB and CIF were designed for sea freight and are best avoided for air shipments, even though they still appear on many quotes.
Choosing the right term decides who books the freight, who pays each charge and when risk passes. Many disputes about unexpected invoices trace back to an Incoterm neither party fully understood.
08Dangerous goods
A surprising number of everyday products are dangerous goods for air transport: lithium batteries, perfume, aerosols, paint, adhesives and dry ice among them. The IATA Dangerous Goods Regulations, updated every year, set how each must be classified, packed, labelled and declared.
In Australia, the Civil Aviation Safety Authority regulates dangerous goods by air, and only trained people may prepare and sign declarations. Undeclared dangerous goods remain one of the most serious risks in air cargo, and the penalties reflect that.