Control Cables: Swaging, Inspection, and Maintenance

This set of vocabulary flashcards covers the materials, tools, testing procedures, and maintenance standards for aircraft control cable systems, including swaging techniques, inspection criteria for fatigue, and various flexible cable types.

Swaging

A process that creates a permanent connection between a control cable and an end fitting by applying pressure.

Hand-woven splice

An obsolete method of terminating cables that provides approximately $75\%$ of the cable strength, replaced by swaging except in vintage aircraft restoration.

Stainless steel cable

A control cable material that is more expensive and has slightly lower tensile strength than carbon steel, but is preferred in harsh environments due to its longer service life and corrosion resistance.

Cold roll forging

The technical term for the swaging process when using Kearney® swaging roll-dies to squeeze a terminal onto a cable.

Go/No-go gauge

A tool used to check the outside diameter of the terminal shank to ensure it corresponds to the cable size and has been reduced to the correct dimension after swaging.

Over-swaging

The act of performing more than four passes in a swager, which causes work hardening or embrittlement and may lead to terminal cracking.

Cable Proof Test

A procedure where a completed cable is loaded to $60\%$ of its breaking strength for at least three minutes to verify the integrity of the installations.

Nicopress®

A patented process using a copper sleeve mechanically compressed into a cable to produce $100\%$ of the cable strength.

Witness Mark

A band of paint applied to the cable and Nicopress® sleeve used to identify if the cable has slipped within the fitting.

Critical fatigue area

Sections of a cable—including working lengths over pulleys, sections that are flexed or rubbed, and any point within $12\,\text{inches}$ ($30.5\,\text{cm}$) of a swaged fitting—where a single broken wire strand requires replacement.

Kinking

Cable damage caused by an unnatural twist (often from improper unreeling) that disturbs the relative adjustment between strands and necessitates replacement.

Blending together

An external wear pattern occurring when individual wires in each strand are worn by $40\%$ to $50\%$, causing them to appear merged.

Fairlead

A tube or guide made of soft plastic or fiber (such as Nylon® or Tufnell®) used to protect cables from rubbing against the aircraft structure; it must never be used to change cable direction.

Pressure seals

Grease-filled components used where control cables pass through a pressure bulkhead to prevent air leakage.

Turnbuckle

A device used to adjust cable tension, featuring a groove to identify the left-hand thread and locked by wirelocking, lock nuts, or spring wire clips.

Tensiometer

An instrument with $98\%$ accuracy that determines cable tension by measuring the force needed to offset the cable between two anvils.

Bowden Cable

A flexible control system that transmits mechanical force via an inner cable moving inside a conduit, typically operating only in the pull direction.

Teleflex Cable

A flexible control system capable of transmitting both push and pull forces without a return spring, often using a cable helix that engages with pinion teeth.