Purpose:

This SAE Aerospace Recommended Practice (ARP) specifies guidelines for calculating and performing shoring (load spreading) required on board civil transport aircraft whenever a piece of cargo to be carried exceeds the aircraft's maximum allowable limits in area load, running load, or both. It provides both the engineering methods needed to properly design a shoring arrangement, and the main practical dos and donts known from experience to ensure its effectiveness in protecting the aircraft's structure against overload.

This document aims at providing recognized industry standard methods to achieve the best attainable level of aircraft structural protection when designing and performing a shoring arrangement, taking into account the general requirements expressed in the aircraft manufacturers Weight and Balance Manuals, the requirements to be met as a result of the air cargo pallets airworthiness certification requisites, as well as the various potential areas of concern identified based on experience.

This document, therefore, provides recommended practical means of compliance with flight safety objectives, intended to be available as a common base for carriers as well as their airport handling agents when establishing their own in-house procedures, publications and staff training programs.

This document, however, is primarily intended for use by qualified structural engineers to be responsible for calculating and implementing cargo shoring arrangements where the size and weight of the piece of cargo require. It is not intended as a guide for more common simpler shoring requirements, identified thereafter: ARP5486, Air Cargo Pallets - Utilization Guidelines, Section 5 addresses such relatively simple cases.

This document shall not, under any circumstance, supersede the requirements of applicable airworthiness regulations (see FAR Part 25) or the aircraft manufacturer's Weight and Balance Manual.

In addition, any aircraft manufacturers specific cargo shoring instructions shall be strictly complied with. Since in several instances they contain proprietary data, such data should be used only by authorized companies and persons with proper understanding thereof.

Field of Application:

This Aerospace Recommended Practice applies to shoring (load spreading) of individual pieces of cargo to be carried on board civil transport aircraft:

a. onto one or several airworthiness certified air cargo pallets meeting the requirements of TSO C90, themselves restrained into aircraft lower, main or upper deck cargo systems, or

b. nonunitized pieces of cargo, or pieces of cargo placed onto one or several unrestrained ("floating") pallet(s) into lower, main or upper deck containerized cargo compartments of an aircraft, or

c. individual pieces of cargo loaded in noncontainerized (bulk loaded) baggage or cargo compartments.

Its field of application includes the pallets and shoring stands prepared within ground premises, whether at a shipper's facilities or an airport cargo warehouse, including those intended to be loaded into the aircraft in a "floating" (not fully system restrained) position requiring tie-down onto the aircraft's structure instead of the pallet's tracks.

Its provisions also entirely apply in the event of "pre-embarked" pallets, i.e., pallets loaded empty into the aircraft to be used as a floor on which cargo is later brought and palletized inside the cargo compartment. In such a case, it pertains to the operator to implement the shoring scheme at aircraft loading.

Cargo shoring instructions shall be established by the aircraft operator, under control of his reporting Authority. The shoring instructions shall ensure compliance with the general airworthiness requirements and the applicable aircraft Weight and Balance Manual, and should incorporate the requirements of the present document, or equivalent industry standard (see 2.2). They should further define load or load concentration limits over which design and/or approval of the shoring scheme by designated load engineering structural engineers (see 7.2) is mandatory prior to implementation.

Actual cargo shoring in accordance with these instructions shall be performed and checked exclusively by an operator approved loadmaster constituting a competent, suitably trained (see 7.3), personnel as defined in ISO 9002, clause 4.18, or equivalent pertinent industry training and proficiency standards.

This document is not intended to be used for cargo shoring aboard military transport aircraft, and does not take into account any specific criteria for military aircraft. Nothing, however, precludes it being used for guidelines in this case, it pertaining to the military operator to identify and implement any additional applicable criteria.