ISO 2020-2:1997

Overview

ISO 2020-2:1997 is the International Standard Part 2 - Technical specification for preformed flexible steel wire rope for aircraft controls. Used together with ISO 2020-1 (Dimensions and loads), this part defines the inspections, test methods, acceptance and qualification conditions that manufacturers, suppliers and testing laboratories must follow to ensure wire rope is fit for aircraft control applications.

Key topics and technical requirements

• Scope of testing and inspection: Specifies mandatory workmanship inspection during reel winding, calibration of instruments and lot-based acceptance and qualification testing.
• Materials and traceability: Requires conformity certificates or chemical analysis for semi‑finished products; manufacture must follow best practices for aircraft wire rope.
• Dimensional control: Diameter measurement method - three points at least 1 m apart with two orthogonal readings each; average must lie within specified limits in ISO 2020-1.
• Workmanship limits: Finished rope must be uniform, free from kinks, loose wires/strands; maximum of one broken wire permitted per 300 mm length.
• Joints and end treatment: Tucked joints allowed for wires ≤0.2 mm; brazing or electric welding required for larger wires; minimum spacing for joints in the same strand.
• Lubrication and surface condition: Lubricant requirements (coating each wire, corrosion inhibition, service temperature resistance) and permissible flattening from manufacture.
• Mechanical tests:
  • Actual breaking load testing per ISO 3108.
  • Elongation procedure for 7x7 and 7x19 constructions, progressive loading steps and measurement points.
  • Endurance (fatigue) test: apparatus and pulleys specified; total cable travel in one direction = 343 mm; post-test breaking load minimums defined.
• Re-test and reporting: Defines retest procedure when failures occur and requirement for a complete test report and certificate of conformity with each lot.
• Quality management: Manufacturer must operate under a certified quality system (ISO 9001 or ISO 9002) and present certification to airworthiness authorities on request.
• Delivery, packing, marking: Limits on consignment sizes, minimum/allowed rope lengths, reel packing and mandatory reel labeling (designation, manufacturer, order and manufacture numbers, date, inspection note).

Applications and users

This standard is essential for:

• Aerospace component manufacturers and suppliers producing aircraft control cables
• Procurement and quality assurance teams verifying supplier conformity
• Test laboratories performing mechanical and endurance tests
• Airworthiness authorities and certification bodies reviewing material acceptance
• Design engineers specifying control cable components for rotorcraft and fixed‑wing aircraft

Related standards

• ISO 2020-1:1997 - Dimensions and loads (companion document)
• ISO 2408:1985 - Steel wire ropes for general purposes
• ISO 3108 - Breaking load test method (referenced)
• ISO 9001 / ISO 9002 - Quality management system requirements

Keywords: ISO 2020-2, preformed flexible steel wire rope, aircraft controls, endurance test, breaking load, wire rope inspection, aerospace standards, quality assurance.