Aircraft Wires and Cables Installation

Aircraft wires inspection.fittings, and proper clamping. Inspect for distortion,
Inspection of wiring and cable integrity should beadequate drain points which are free of dirt, grease,
done by inspecting interconnecting wiring, aircraftor other obstructions, and freedom from abrasion or
cables installation, and conduit between various piecesdamage due to moving objects such as aircraft
of electronic equipment to determine that they docontrol cables or shifting cargo.
not rub against the airframe or each other underPLASTIC WIRE SLEEVING. Inspect plastic wire
vibration conditions encountered in flight. Inspectsleeving for damage due to abrasion, solvents, or
open wiring and cabling for fraying, damage orhydraulic fluids.
distortion resulting from heavy objects being placedELECTRICAL TAPE. The chemical base of most
on them, being stepped on, or being used asplastic electrical tape is polyvinylchloride (PVC). This
handholds.tape is not flame resistant unless it is specially
PROTECT FROM FLUIDS. Separate aircraft wires orprocessed to make it so. Some manufacturers are
cables from flammable fluids lines or those whichproducing flame-resistant PVC tape and have
carry fluids which have a deteriorating effect on wireobtained Fire Underwriter's Laboratory (UL) approval
insulation. Wiring or cables should be routed abovewhich is shown on the wrapping of the container.
such lines and securely clamped to the aircraftUnless the tape shows such approval, it should not
structure. An arcing fault between an electric cablebe used until its flame resistance properties have
and a fluid line may puncture the line and result in abeen determined. A simple test can be made by
fire.applying a flame to a sample of unknown tape and
Aircraft wiring replacement.comparing its burning qualities to a sample of
WIRE AND CABLE CLAMPS. Inspect aircraft wire andflame-resistant tape.
cable clamps for proper tightness. Where cables passHigh temperature fire resistant cable
through structure or bulkheads, inspect for properFlame resistant or not, PVC will decompose at
clamping or grommets. Inspect for sufficient slacktemperatures above 221* F. (105° C.) with rapid loss
between the last clamp and the electronic equipmentof insulating qualities. It is not recommended for use
to prevent strain at the cable terminals and minimizein compartments where temperatures normally
adverse effects on shock mounted equipment.approach 221° F. (105° C.) nor in designated fire
CONDUIT. Conduit is manufactured in metallic andzones unless precautions are taken to prevent short
nonmetallic materials and in both rigid and flexiblecircuits to the airframe, shielded wires in bundles, or
forms. Primarily its purpose is for mechanicalany other electrical ground, in the event of
protection of the cable within. Inspect conduit fordecomposition. Of course, high temperature fire
proper end fittings, absence of abrasion at the endresistant cable should be used wherever possible.