Heavy Air Freight

There is no single official line, but most shippers treat anything beyond parcel network limits as heavy air freight. Parcel services generally cap individual pieces at around 150 pounds, so heavier boxes, palletized loads, crates and machinery move as air freight instead. Within air freight, the real limits come from the aircraft: how much weight a piece puts on the floor, whether it fits through the cargo door, and whether it fits a passenger aircraft hold or needs a freighter. A shipment can be heavy because of one large piece or because of many pallets together.

It depends on the aircraft. Passenger aircraft holds take only modest piece heights. Main-deck freighters take larger pallets and crates through wide side doors. Freighters with nose doors can load long pieces straight into the fuselage, and outsize aircraft with very large nose doors and internal cranes carry single items that nothing else can, such as large industrial equipment. The usable size also depends on the airport's loading equipment. Shippers should share every piece's dimensions and weight so the aircraft and airports can be checked before booking.

On a freighter, the main deck is the large upper cargo floor where passengers would sit on a passenger aircraft. It takes full-size pallets and large crates through a wide side door or, on some aircraft, a nose door. The lower deck, often called the belly, sits under the main deck and takes smaller pallets, containers and loose freight through smaller doors. On passenger aircraft, all cargo rides in the lower deck. Heavy and tall pieces usually need main-deck space on a freighter.

A nose door is a cargo door at the front of a freighter that swings up to open the whole front of the fuselage. Long items such as pipe, blades or large containers can then be pushed straight in along the aircraft's length on rollers, instead of being turned through a side door. Only some freighters have nose doors, which makes them valuable for long or awkward heavy freight. The size of the nose door and the length of the cargo floor set the limits for what can be loaded this way.

Belly cargo flies in the lower holds of passenger aircraft, beneath the passengers. It benefits from the large number of passenger flights but is limited in piece size and height, and it must be screened before loading. Freighter cargo flies on aircraft dedicated to freight, with main-deck space for large pallets and pieces. Freighters fly fewer routes than passenger aircraft, but they handle heavier and larger freight. Heavy shipments often need a freighter, while smaller pallets can ride in the belly of a passenger flight.

Chargeable weight is the weight used to bill an air shipment: the greater of actual weight and dimensional weight. Dimensional weight is the length, width and height in inches multiplied together and divided by a set factor, commonly 166 for US domestic freight. Light, bulky freight is charged by its dimensions, because it fills space. Dense, heavy freight such as machinery is usually charged by its actual weight. For heavy shipments, an accurate scale weight matters most, because carriers reweigh freight and adjust the charge if the declared weight was wrong.

Out-of-gauge cargo is freight that is too large in one or more dimensions to fit standard pallets, containers or doors. In air freight, it means a piece that exceeds the normal pallet outline or the door size of common aircraft. Out-of-gauge pieces need special planning: a freighter with a larger door or a nose door, extra loading equipment, and sometimes an outsize aircraft. Measuring the piece precisely, including any protrusions, lets the right aircraft be chosen before the freight reaches the airport.

A ULD, or unit load device, is a standard aircraft pallet or container used to group freight so it can be loaded and secured quickly. Pallets are flat platforms where freight is stacked and held with nets and straps. Containers are enclosed boxes shaped to fit the curve of the aircraft. Each aircraft type accepts specific ULD sizes in specific positions. Heavy pieces are built onto ULDs at the airport, and their weight must be spread so it stays within the aircraft's floor and position limits.

An air waybill is the shipping document and contract of carriage for air freight. It lists the shipper, consignee, airports, pieces, weight and dimensions, and it is not a document of title. A bill of lading is the equivalent document for truck and ocean freight. An ocean bill of lading can be a document of title, which means it can be used to transfer ownership of the goods. Heavy freight that moves partly by truck and partly by air may carry a bill of lading for the road legs and an air waybill for the flight.

Carrier liability for air freight is limited and often calculated by weight, so it may cover only a fraction of the value of expensive machinery or equipment. Many shippers buy separate cargo insurance for heavy, high-value shipments to cover the full value against loss or damage. The right coverage depends on the value of the goods, the route and any existing policies the shipper already holds. Accurate crating, labeling and handling instructions also help prevent claims, since heavy pieces are most at risk during loading and transfers.

Some dangerous goods are forbidden on all aircraft. Others can fly only on cargo aircraft, not passenger planes, and many more can fly when they are properly classified, packed, marked, labeled and declared. Heavy equipment can raise questions of its own, such as fuel left in engines, batteries, compressed gas cylinders and hydraulic fluids, which may need to be drained, removed or declared. In the United States, the hazardous materials regulations apply, and most airlines also follow IATA rules. The airline or operator decides whether to accept a shipment, so declare everything up front.