Control Cable Inspection; Cable Damage; External Wear Patterns Of Cable; Internal Cable Wear - Piper PA-44-180 SEMINOLE Maintenance Manual

CONTROL CABLE INSPECTION

Aircraft control cable systems are subject to a variety of environmental conditions and forms of deteriora-
tion that, with time, may be easy to recognize as wire/strand breakage or the not-so-readily visible types of
wear, corrosion, and/or distortion. The following data may help in detecting the presence of these conditions:

CABLE DAMAGE

Critical areas for wire breakage are sections of the cable which pass through fairleads and around pulleys.
To inspect each section which passes over a pulley or through a fairlead, remove cable from aircraft to the
extent necessary to expose that particular section. Examine cables for broken wires by passing a cloth along
length of cable. This will clean the cable for a visual inspection, and detect broken wires, if the cloth snags on
cable. When snags are found, closely examine cable to determine full extent of damage.
The absence of snags is not positive evidence that broken wires do not exist. Figure 2A shows a cable
with broken wires that were not detected by wiping, but were found during a visual inspection. The damage
became readily apparent (Figure 27-2B) when the cable was removed and bent using the techniques depicted
in Figure 27-2C.
EXTERNAL WEAR PATTERNS
Wear will normally extend along cable equal to the distance cable moves at that location. Wear may occur
on one side of the cable only or on its entire circumference. Replace flexible and non-flexible cables when
individual wires in each strand appear to blend together (outer wires worn 40-50 percent) as depicted in
Figure 27-3.

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 27-4, is not easily detected unless the strands of the cable are separated. Wear of this type is a result of
PIPER AIRCRAFT
PA - 4 4 - 1 8 0 / 1 8 0 T
AIRPLANE MAINTENANCE MANUAL
Figure 27-2. Control Cable Inspection Technique
1K5
27-00-00
Page 27-3
Added: June 20, 1995