Piper Comanche PA-24 Service Manual page 255

C. Internal Cable Wear
As wear is taking place on the exterior surface of a cable, the same condition is taking place
internally, particularly in the sections of the cable which pass over pulleys and quadrants. This
condition, shown in Figure 5-4, is not easily detected unless the strands of the cable are separated.
Wear of this type is a result of the relative motion between inner wire surfaces. Under certain
conditions the rate of this type wear can be greater than that occurring on the surface.
D. Corrosion
Carefully examine any cable for corrosion that has a broken wire in a section not in contact with
wear producing airframe components such as pulleys, fairleads, etc. It may be necessary to remove
and bend the cable to properly inspect it for internal strand corrosion as this condition is usually not
evident on the outer surface of the cable. Replace cable segments if internal strand rust or corrosion
is found.
Areas especially conducive to cable corrosion are battery compartments, lavatories, wheel wells,
etc., where concentrations of corrosive fumes, vapors, and liquids can accumulate.
NOTE: Check all exposed sections of cable for corrosion after a cleaning and/or metal-brightening
operation has been accomplished in that area.
04/01/09
PIPER COMANCHE SERVICE MANUAL
Figure 5-3. External Cable Wear Patterns
1F19
V - SURFACE CONTROLS