Overview
ISO/TR 21891:2017 compiles, in a single technical report, the international and national standards considered suitable for use on aircraft for insulation and mechanical/environmental protection sleeves and heat‑shrink moulded shapes. It covers a broad range of sleeve types - heat‑shrink, extruded (non‑heat‑shrink) and textile - and identifies applicable standards, usage notes and known limitations for aerospace electrical applications. The report references IEC/ISO definitions, test methods and compatibility requirements to support selection and specification of sleeve and moulded shape materials for aircraft harnesses and equipment.
Key Topics
- Scope and definitions: Uses terms from IEC 60684‑1 (Flexible insulating sleeving - definitions and general requirements).
- Standards list: Consolidated table of relevant standards (IEC 60684 series, IEC 62329 series, EN 6049/4674 series, and related national specifications such as BS, VG, MIL and AMS references).
- Material categories: Heat‑shrink polyolefin and elastomeric moulded shapes; extruded polychloroprene, silicone, fluorosilicone and PTFE sleeving; braided textile (PET, E‑glass, ETFE/ECTFE) and aramid-based wraparound/self‑wrapping sleeves.
- Performance attributes: Flame retardancy/limited fire hazard, smoke/gas/toxicity minimization, chemical and hydraulic fluid resistance, high‑temperature capability (examples in the report include sleeving rated up to ~130 °C, 155 °C and 350 °C), mechanical abrasion protection, strain relief and environmental sealing (dual‑wall with meltable liner).
- Special functions: EMI shielding (self‑wrapping with nickel‑plated copper braid), fire protection sleeves, marker sleeves and system compatibility considerations.
- Test methods & system compatibility: References to IEC 60684‑2 and IEC 62329‑2 for methods of test and performance verification; SAE AS 5258 for system compatibility in some cases.
Applications
ISO/TR 21891:2017 is intended to guide selection, procurement and specification of sleeving and moulded shapes used in:
- Aircraft wiring harness design and assembly
- Electrical/electronic equipment protection (avionics, sensors, power distribution)
- Maintenance, repair and overhaul (MRO) activities for replacement components
- Certification and qualification testing, and supplier conformity assessment
- EMI mitigation and fire/smoke risk reduction in cabin and systems areas
Typical users: aerospace electrical engineers, harness designers, procurement/specification authors, qualification/test laboratories, MRO technicians and certification authorities.
Related Standards
- IEC 60684 series (flexible insulating sleeving: definitions, types, test methods)
- IEC 62329 series (heat‑shrinkable moulded shapes: definitions, tests, dimensional/material requirements)
- EN 6049 / EN 4674 series (textile and self‑wrapping protective sleeves)
- National and industry specs referenced in the report (BS, MIL, AMS, VG, SAE)
Keywords: aerospace electrical requirements, sleeves, heat shrink, moulded shapes, aircraft use, insulation sleeves, EMI shielding, flame retardant, fluid resistant.
