ISO 9788:2017

Overview

ISO 9788:2017 - Air cargo - Double stud tie-down fittings - Design and testing requirements - specifies the geometry, materials, performance and test procedures for double stud tie-down fitting assemblies used in air cargo restraint systems. The standard applies to fittings with a minimum breaking strength of 22 250 N (5 000 lbf) when installed in rails or tracks conforming to ISO 7166. It provides one means of compliance with civil aviation airworthiness requirements for cargo restraint hardware.

Key topics and technical requirements

• Geometry & interchangeability
  • Defines body and plunger configuration (maximum envelope dimensions and critical interchangeability dimensions). Figures show permitted shapes and plunger clearance requirements.
  • Ring shapes are illustrated (oblong preferred to minimize interference in confined pallet/ramp spaces).
• Materials
  • Body: forged steel, or malleable cast iron grade P70‑02, or equivalent tensile strength material.
  • Plunger: malleable cast iron grade B35‑10 or equivalent shear strength material.
  • Other components: any suitable material meeting strength and geometry requirements.
• Surface treatment
  • Non‑corrosion resistant materials shall have protection at least equivalent to 12 µm zinc chromate; zinc chromate’s toxicity is noted and alternative treatments are recommended.
• Load and strength
  • Minimum breaking strength: 22 250 N (5 000 lbf) in any direction.
  • For cast components, a casting factor (1 to 2) may be applied according to airworthiness authority and inspection regimes.
• Testing and certification
  • Mechanical load tests in multiple directions (P1–P4) installed in ISO 7166-compliant rail/track.
  • Sampling and inspection per ISO 2859‑1 and ISO 3951; mechanical tests per ISO 5922 and ISO 6892.
  • Requirements for retesting, deformation limits, designation, identification and quality control are specified.

Applications and who uses ISO 9788:2017

• Manufacturers of tie-down fittings, pallet hardware and pallet nets who need to design and certify parts to a recognized aviation standard.
• Aircraft equipment designers and integrators ensuring interchangeability with aircraft floor rails and unit load device tracks.
• Certification authorities, test labs and quality control teams performing strength and sampling inspections for airworthiness compliance.
• Operators and ground handling organizations selecting compatible restraint components (used with restraint straps per ISO 16049‑1 or slings per ISO 20291‑1).
• Applicability includes loose fittings for pallets/rails and permanently attached components of pallet nets (ISO 4115 / ISO 4170).

Related standards (for compliance context)

• ISO 7166 - aircraft rail and stud configuration
• ISO 16049‑1 - restraint straps design and testing
• ISO 20291‑1 - cargo restraint slings
• ISO 4115, ISO 4170 - pallet nets
• ISO 2859‑1, ISO 3951, ISO 5922, ISO 6892 - sampling and mechanical testing

ISO 9788:2017 helps ensure safe, interoperable double stud tie-down fittings for air cargo operations by combining clear design geometry, material guidance and rigorous testing protocols.