Overview
ISO 4116:1986 defines requirements for ground and terminal handling equipment that directly affect the service life of aircraft unit load devices (ULDs). Its purpose is to prevent undue wear and damage to containers, pallets and galley modules by establishing design and operational criteria for conveyors, guides, stops and restraint hardware used on trucks, transporters, dollies, storage provisions and pallet build-up hoists.
This International Standard was prepared by ISO/TC 20 (Aircraft and space vehicles) and is intended to be applied to equipment manufactured or installed after its publication. It complements device manufacturer guidance, airline operator practices and applicable IATA specifications.
Key Topics
-
Conveyor systems (uni-directional and multi-directional)
- Minimum roller diameter: 50 mm (2 in) and minimum effective bearing length: 100 mm (4 in).
- Cumulative roller length on a common axis shall support at least 50% of the corresponding device dimension; staggered roller patterns are acceptable.
- Ball-transfer and castored-roller spacing and diameter requirements are specified to limit point loads and reduce wear (examples in the standard: ball diameter min 25 mm (1 in); ball pre-load suggested close to 310 N (70 lbf), not less than 150 N and not exceeding 450 N).
- Allowable height differences for rollers and unloaded ball transfers: maximum 3.2 mm in any 1.52 m x 1.52 m area, and 1.3 mm between adjacent units.
-
Flat-top systems and contact requirements
- Flat conveying or storage surfaces must provide a minimum percentage of contact area (20% for transient traversing conditions) and limit overhangs to specified maxima.
-
Stops, guides and restraints
- Guide rails and end stops typically extend at least 101.6 mm above the conveying surface; centre-to-centre distance for stops shall not exceed 635 mm and minimum width is 50.8 mm.
- Systems must provide fore, aft, lateral and vertical restraint; energy-absorbing stops are required where impact velocities exceed defined thresholds.
-
Operational procedures
- Transport speed categories and rules for door latching, net securing, stacking limitations and pre-movement restraint application are covered to reduce damage and risk during handling.
Applications
- Ground equipment manufacturers: design validation and specification of conveyors, dollies and pallet-handling devices.
- Airport and airline cargo operations: selection and maintenance of handling systems to extend ULD life and reduce lifecycle costs.
- Maintenance and safety teams: verifying restraint, stop and guide performance to improve personnel safety and prevent cargo damage.
Related Standards
- ISO 4116 references device manufacturer requirements, airline operator practices and IATA specifications for detailed sizing and installation matters.
- Prepared by ISO/TC 20 (Aircraft and space vehicles); users should consult the latest editions of referenced International Standards and industry guidance when applying ISO 4116:1986.
For design, procurement or audit activities, consult the full ISO 4116:1986 document and coordinate with ULD manufacturers and airline operations to ensure compatibility and compliance.
Open preview (PDF)Air cargo equipment — Ground equipment requirements for compatibility with aircraft unit load devices
