The HCU-6/E or 463L Master Pallet is a standardized pallet used for transporting military air cargo. It is the main air-cargo pallet of the United States Air Force, designed to be loaded and offloaded on today's military airlifters as well as many civilian Civil Reserve Air Fleet (CRAF) cargo aircraft.

A unit load device (ULD) is a container used to load luggage, freight, and mail on wide-body aircraft and specific narrow-body aircraft. It allows preloading of cargo, confidence the containerised load will fit in the aircraft and efficient planning of aircraft weight and balance and reduced labour and time in loading aircraft holds compared with 'bulk-loading' single items of cargo or luggage by hand. Each ULD has its own packing list or manifest so that its contents can be tracked. A loaded aircraft cargo pallet secured with a cargo net also forms a ULD, but its load must be gauged for size in addition to being weighed to ensure aircraft door and hold clearances.