Large aircrafts such as the Boeing 747 employ quick-loading containers known as Unit Load Devices (ULDs), much like containerized cargo ships. The ULDs are located in front section of the aircraft.
A unit load device, or ULD, is a pallet or container used to load luggage, freight, and mail on wide-body aircraft and specific narrow-body aircraft. It allows a large quantity of cargo to be bundled into a single unit. Since this leads to fewer units to load, it saves ground crews time and effort and helps prevent delayed flights. Each ULD has its own packing list (or manifest) so that its contents can be tracked.
ULDs come in two forms – Pallets and Containers.
ULD pallets are rugged sheets of aluminium with rims designed to lock onto cargo net lugs. ULD containers, also known as cans and pods, are closed containers made of aluminium or combination of aluminium (frame) and Lexan (walls), which, depending on the nature of the goods to be transported, may have built-in refrigeration units. Examples of common ULDs and their specifics are listed below.
| Unit Load Containers | Inter- changeability | Usable Volume | Max. Net weight capacity | IATA code | IATA rate class | Other Information |
238.5 x 96 inch 20-ft pallet  | 74F main deck / selected truck routes | 33 m3 / 1080 cu. ft | 10,910 kg/ 24,052 lbs | PGA | 1/15 | Height may be 298 cm (117″) for single pieces only, due to lashing equipment. |
196 x 96 inch 16-ft pallet  | 74F main deck / selected truck routes | 27 m3 / 953 cu. Ft | 7,045 – 10,980 kg/ 15,531 – 24,206 lbs | PZA | 1P | Height may be 294 cm (116″) for single pieces only, due to lashing equipment. This pallet can also be built in the same way as the 20- foot pallet. |
96 x 125 inch 10-ft container  | 74F main deck / selected truck routes | 16.7 m3 / 590 cu. ft | 4,565 – 6,549 kg/ 10,066 – 14,438 lbs | AQA AMA | 2/20 | Door opening is 291 x 231 cm or 114 x 91 “ |
96 x 125 inch pallet  | 74F main deck / selected truck routes 74F / D1F lower deck/ 743 / 767 / 777 / M 11 / 330 / 340 / truck | 11,4 m3 / 403 cu. ft | 4,516 – 6,694 kg/ 9,958 – 14,760 lbs | P6P PQP PMC PMP | 2/2Q | Max. height: 160 cm / 63″ |
96 x 125 inch LD-9 container  | 74F / D1F / 743 / 767 / 777 / M 11 / 330 / 340 / truck | 11.0 m3 / 388 cu. ft | 6,564 kg/ 14,586 lbs | AMP | 5 | – |
88 x 125 inch (LD-7) pallet  | 74F / D1F / 743 / 767 / 777 / M 11 / 330 / 340 / truck | 10.5 m3 / 370 cu. ft | 4,516 – 6,694 kg/ 9,958 – 14,760 lbs | PAP PAJ PAP P1P | 5 | – |
Weights depend on the structural weight limitations of the different pallet /container positions in the aircraft. Container sizes may vary depending on Carrier equipment.
