I. Background of Revision
Driven by growing domestic demands for logistics efficiency and quality, air logistics has achieved rapid development. The total cargo and mail throughput of China's civil aviation industry has risen sharply over the past decade, accompanied by expanding airport scale and quantity as well as larger cargo aircraft fleets. The boom of e-commerce in recent years has further boosted demand for air logistics. As standardized loading units widely adopted in air logistics, aircraft pallets play a vital role in lifting air cargo handling efficiency, enhancing cargo transportation safety and ensuring stable aircraft operation.
Since its release, the former national standard Technical Specifications and Test Methods for Air Cargo Pallets (GB/T 18227-2000) has positively regulated the production and testing of aircraft pallets in China. Nevertheless, industrial evolution has generated new technical requirements covering pallet models, maximum operational gross mass, ultimate load capacity, testing items and frame cross-section dimensions, rendering the old standard unable to meet current industrial application scenarios. Meanwhile, updated editions of relevant standards such as Technical Requirements for Air Cargo Unit Load Devices (GB/T 15140) have been issued, alongside newly released national standards including Air Cargo and Ground Equipment – Terminology (GB/T 23418) and international standard ISO 21100 Air cargo unit load devices-Performance requirements and test parameters. To satisfy practical demands for the design, production and application of aircraft pallets and maintain the applicability and advancement of standard technical provisions, the Ministry of Transport organized relevant institutions to revise Technical Specifications and Test Methods for Air Cargo Pallets.
II. Positioning and Functions of the Standard
This standard specifies the marking, dimensions, operational gross mass, general requirements and technical requirements of aircraft pallets, and describes corresponding test methods. It applies to the design, production and use of aircraft pallets with size codes A, B, G, K, L, M, N, Q, R and S, and excludes aircraft pallets equipped with fire shields.
The revision of this standard is based on actual technical specifications of aircraft pallets manufactured and applied domestically, meeting demands for designing, producing and inspecting aircraft pallets compatible with existing aircraft dimension systems. Upon issuance and implementation, this standard will: first, standardize and guide the domestic standardized production of aircraft pallets and align relevant products with international standards; second, exert great significance in guaranteeing the production quality of aircraft pallets. Domestic aircraft pallets complying with this standard can withstand extreme operating conditions in air transport with high strength, rigidity and hardness, safeguarding the safety of cargo and aircraft during transit and supporting high-quality development of air logistics.
III. Major Revisions
Compared with GB/T 18227-2000, major revisions are summarized as follows:
(1) Standard Title and Scope
In compliance with standard compilation specifications, the standard title is revised from Technical Specifications and Test Methods for Air Cargo Pallets to Technical Requirements and Test Methods for Aircraft Pallets. Based on revised and newly added technical contents, combined with domestic application status and development prospects of aircraft pallets, the scope is updated to cover the design, production and use of aircraft pallets with size codes A, B, G, K, L, M, N, Q, R and S, excluding pallets fitted with fire shields.
(2) Markings
With the development of the aircraft pallet industry and in line with general ULD marking criteria set out in ISO 21100 and IATA ULDR, marking codes and compositions stipulated in the old standard have been adjusted. Specific revisions include: integrating the former chapters "Symbols" and "Marks" into a unified chapter "Markings" with additional composition requirements; renaming "Marks" to "Identification Marks" and updating relevant content; adding requirements for CTSO marking.
(3) Dimensions and Operational Gross Mass
Due to the expanded scope of applicable aircraft pallets, dimensional and operational mass requirements specified in the old edition are no longer applicable. In accordance with China's civil aviation regulations and technical standards, as well as the latest provisions of ISO 21100 and IATA ULDR, dimensional and operational gross mass requirements are formulated for aircraft pallets with size codes A, B, G, K, L, M, N, Q, R and S. Thickness dimensional requirements for aircraft pallets are newly added based on practical industrial applications.
(4) General Requirements
To facilitate understanding and implementation for standard users, the logical structure of the old standard is rearranged. Provisions covering materials, design, assembly, surface and bottom surfaces extracted from the original "Technical Specifications" are refined. Following civil aviation regulatory requirements and technical standards, together with the latest rules of ISO 21100 and IATA ULDR, new clauses are added concerning pallet materials, design, assembly, surface flatness and edge flatness.
(5) Technical Requirements
In accordance with China's civil aviation regulations and technical standards, citing technical clauses on pallets specified in ISO 21100 and combined with practical industrial applications, revisions are made as below: adjusting strength requirements for restraint rails on frames; revising deformation requirements for upper restraint surfaces on bottom panels to "deformation limits" and adding deformation limits under no-load condition; merging original technical clauses on ultimate load and structural strength; deleting technical contents including panel core rigidity, straddle carrier operation, limit load and compatibility of pallets with cargo nets.
(6) Test Methods
Corresponding test methods are formulated to match updated technical requirements, complying with China's civil aviation regulations and technical standards, the latest provisions of ISO 21100 and IATA ULDR, and practical industrial operation. A test for minimum frame rigidity is newly added in accordance with current industrial calculation methods for testing. As restraint rails need to satisfy both double rear lock and single rear lock applications, the strength test for restraint rails adopts the stricter double rear lock criteria. The technical indicators of the newly added ultimate load test exceed those of the former static strength test and straddle carrier test, hence the static strength test and straddle carrier test are removed.
(7) Appendices
Informative Appendix Aircraft Cargo Hold Floor System This appendix is deleted as straddle carrier operation requirements are removed, rendering this appendix irrelevant for reference.
Normative Appendix Cross-section Dimensions of Aircraft Pallet Frames Illustrations of pallet frame cross-section dimensions are revised to conform to updated provisions of IATA ULDR.
Deletion of Normative Appendix Center-of-gravity Range and Restraint Conditions for Pallets Used with Cargo Nets The expanded scope of applicable aircraft pallets makes the original center-of-gravity and restraint provisions limited in adaptability. ISO 21100 cited in the ultimate load clauses of this standard fully covers center-of-gravity ranges and restraint conditions, so this appendix is deleted.
Deletion of Normative Appendix Schematic Diagram of Pallet Marking Positions Only general principles rather than mandatory specifications are provided for pallet marking positions per updated IATA ULDR rules and the expanded pallet coverage, so this appendix is removed.
Deletion of Informative Appendix Schematic Diagrams of Test Methods and Equipment for Pallet Service Requirements Revisions are made to schematic diagrams for restraint rail strength tests to align with civil aviation regulations, ISO 21100, IATA ULDR and industrial practice; relevant diagrams are moved to the main text. The straddle carrier test is cancelled, and textual descriptions for the steel roller test are sufficiently clear for implementation without diagrams, leading to the deletion of this appendix.
IV. Notes on Implementation
For the implementation of this standard, users shall apply it together with the latest valid editions of the following standards:
Air Cargo and Ground Equipment – Terminology (GB/T 23418)
Technical Requirements and Test Methods for Air Cargo Pallet Nets (GB/T 18228)
International Standard ISO 21100 Air cargo unit load devices-Performance requirements and test parameters
IATA ULD Technical Manual (IATA ULDR)
