I suspect what You call mean by "... composite fairlead designed to be installed around the lightening hole as protection for the cable..." is actually composite 'catapillar grommet' M22529/2-X. This edging material is strictly intended for steady state contact and/or incidental tapping contact to prevent damage to the edges of pass-thru parts. Rubbing across or along it will dislodge the edging and/or will wear Your cable/edging until the structure and/or the cable is damaged.
A true failead is a different animal [see below].
Your acft FCS was probably designed to meet MIL-F-9490D "FLIGHT CONTROL SYSTSMS - DESIGN, INSTALLATION AND TEST OF PILOTED AIRCRAFT, GENERAL SPECIFICATION FOR" [superseded by the current DoD spec for flight control system design SAE AS94900].
For a copy of MIL-F-9490D, go to... https://assist.daps.dla.mil/quicksearch/
220.127.116.11.1 Control element routing. Within the restrictions and requirements contained elsewhere in this specification,al1 portions of signal transmission subsystems,including cables, push-pull rods, torque tubes, and electrical wiring shall be routed through the airplane in the most direct manner over
the shortest practical distances between points being connected. Protection from use as steps or handholds shall be provided.
18.104.22.168.2 System separation,protection, and clearance. Where redundant cable, pushrod, or electrical wiring are provided, they shall be separated as required to meet the invulnerability requirementsof 3.1.9. Advantage shall be taken Of the shielding afforded by heavy structural members, existing armor plate, or
other equipment for the protection of important components of the control systems. Clearance between f1ight control system components and structure or other components shal1 be provided as necessary to insure that no probable combination of temperature effects, air loads, structural deflections, vibrations, buildup
of manufacturing tolerances, or wear, can cause binding or jamming of any portion of the control system. In locally congested areas only, the following minimum clearances may be used after all adverse effects are accounted for:
a. l/8-inch between static elements except those within an LRU where closer clearances can be maintained or where contact cannot be detrimental.
b. l/8-inch between elements which move in relation.to each other and which are connected to or are guided by the same structural or equipment element(s) except those within an LRU where closer clearances can be maintained or where contact cannot be detrimental.
c. l/4-inch between elements which move in relation to each other and which are connected to or are guided by different str~ctural or equipment elements.
d. 1/2-inch between elements and aircraft structure and equipment to which the elements are not attached.
22.214.171.124.3 Fouling prevention. All elements of the flight control system shall be designed and suitably protected to resist jamming by foreign objects.
126.96.36.199.4.12 Fairleads and rubbing strips. Fairleads shal1 not cause any angular change greater than 3 degrees in the direction of the cable underall conditions including those due to structural deflections in flight. Fairleads shall be split to permit easy removal unless the size of the hole is sufficient to permit the cable with swage terminals to be threaded through.
This spec has lots of other good info You should be aware of.
OBVIOUSLY rubbing contact between a cable [wire-rope] and a sof element not intended for rubbing by a wire-rope is a set-up for damage.
Along with the inspection comments provided by the "other guys", suggest You check the pulley axis-bolts and bracket holes for wear/elongation/distortion.... and ensure that the pulley-cable alignment is within -9490 spec allowables, as follows...
188.8.131.52.4.6 Cable and pulley alignment. Fixed-mounted pulleys shal1 be aligned with their cables within 2 degrees as specified in AFSC Design Handbook DH 2-1, I DN 3B1, Subnote 1.1.3(1), Cable Pull. Where a control cable has an angular motion with respect to the plane of the pulleys, the maximum misalignment resulting from this motion must not exceed 2 degrees, and the cable shall not
contact the pulley (or quadrant) flange for the total cable travel.
Regards, Wil Taylor
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