Overview
ISO 1966:1973 - "Crimped joints for aircraft electrical cables" defines design requirements, inspection and test methods for crimped terminations and splices used in aircraft wiring. It covers both insulated and non‑insulated terminations for general‑purpose aircraft cables with conductors of copper, copper alloy, aluminium or aluminium alloy, and for locations where stabilized conductor temperatures do not exceed 105 °C, 190 °C or 260 °C. The manufacturer must declare the cable type intended for each termination.
Key topics and technical requirements
- Scope and declarations: Termination type, material, protective treatment, dimensional limits, recommended tools/dies and crimp settings must be declared by the manufacturer.
- Design features: Joints should form a conductor crimp and an insulation grip in one operation where applicable; size‑12 (and smaller) cables require insulation grip unless equivalent support is provided.
- Materials and finishes: Protective treatments must avoid excessive electrochemical potential differences; conducting surfaces should not exceed 0.25 V potential difference to prevent corrosion/electrochemical issues.
- Tools and dies: Crimping tools must locate and control crimp position, not release until crimp is formed, mark the die/tool size, and be traceable (manufacturer name and serial number). Dies must be interchangeable or clearly identified.
- Marking: Completed crimp joints should carry an identification code (embossed or indented) indicating die/tool size where practicable.
- Environmental and performance tests: Defined type and production tests include:
- Inspection (form, dimensions, conductor insertion, absence of fractures)
- Voltage drop (measured under specified currents/conditions)
- Climatic exposure and load/temperature cycling
- Tensile tests (destructive pulls to verify mechanical strength)
- Insulation grip tests and fluid resistance (immersion in aviation fuels, oils, hydraulic and de‑icing fluids)
- Test conditions and sampling: Type tests use multiple specimens (e.g., sixteen specimens per sequence) and standardized environmental conditions (typical reference: 20 ± 5 °C, 930–1070 mbar, RH ≤ 80%).
Applications
ISO 1966 is directly applicable to design, manufacture and qualification of crimped terminals, pin/socket contacts and cable splices used in:
- Aircraft wiring harnesses and electronic equipment
- Aerospace component manufacturers and connector suppliers
- Quality assurance and test laboratories performing crimp qualification
- Maintenance and repair organizations verifying replacement terminations
Who should use this standard
- Aerospace electrical/mechanical engineers
- Harness and connector manufacturers
- Quality & certification engineers (airworthiness and procurement)
- Maintenance, repair and overhaul (MRO) technicians
Related standards
ISO 1966 is intended to be used alongside appropriate national and international standards for aircraft cables, connectors and crimping equipment, and with cable‑specific specifications that define conductor temperature classes and dimensional limits.
Keywords: ISO 1966, crimped joints, aircraft electrical cables, crimping, terminal ends, insulation grip, voltage drop test, tensile test, tools and dies, aerospace wiring.
