BS ISO 21785:2020 pdf free.Air cargo unit load devices一 Load distribution model.
BS ISO 21785 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. When designing aircraft cargo compartments structure and systems, it is recommended the load distribution assumptions defined in 4.1.3 be used to take into account maximum allowable ULD C.G. deviation limits. However, airframe manufacturers may use for this purpose alternate assumptions, providing aircraft structure and systems compatibility with the reference load distribution model is demonstrated. When developing detailed unit load devices utilization rules, operators shall use the reference load distribution model as the assumption describing the most critical C.G. eccentricity case. They shall in addition apply any requirements set forth by the aircraft type’s Weight and Balance Manual, and may also apply the requirements of Clause 5. During ULD build-up, all steps should be taken, insofar as feasible due to the nature, shape and density of cargo to be loaded, to provide a loaded ULD C.G. location as close as possible to its geometric centre. When the nature or shape of cargo makes this impossible in practice, the objective should be to limit C.G. offset to one direction only, either longitudinal or lateral, not exceeding the maximum allowable offset in that direction. Only as a last resort, when dictated without alternative by the nature or shape of cargo, should both longitudinal and lateral maximum C.G. offsets be simultaneously used.  BS ISO 21785 pdf download.