ISO 21785:2020

This document defines the industry agreed model for load distribution on air cargo unit load devices (ULD) bases to apply the maximum allowable centre of gravity (C.G.) eccentricity.
Its purpose is to establish a common reference load distribution algorithm for:
a)   comparable and repeatable ULD testing methods, or equivalent numeric simulations;
b)   aircraft structure and cargo systems design assumptions, consistent with existing airframers practices; and
c)   definition of operators unit load devices utilization rules and cargo build-up training programs.
It applies to all types of unit load devices intended for use on board civil transport aircraft and airworthiness approved in accordance with the performance requirements and testing parameters of either ISO 21100 or, as applicable, ISO 8097.
It also applies to non-airworthiness approved (non-certified) containers as defined in ISO 4118, the utilisation of which is controlled by the provisions of the aircraft type's Weight and Balance Manual and other airframe manufacturer's documents.