FAA Aviation Mechanic Airframe (AMA)Airframe InspectionHard
A technician inspecting a 7x19 control cable near a pulley finds several broken wires. According to general cable inspection criteria in AC 43.13-1B, what is the primary factor used to determine if the cable must be rejected due to broken wires?
- AThe total number of broken wires anywhere along the entire cable length
- BThe number of broken wires within one cable lay length and their location relative to fittings
- CThe color of the broken wire strands compared to surrounding wires
- DWhether any broken wires are visible to the naked eye at all
Show answer & explanationAnswer & explanation
Correct answer: B. The number of broken wires within one cable lay length and their location relative to fittings
AC 43.13-1B provides rejection criteria based on the number of broken wires found within one cable lay length, with lower allowable limits near end fittings and fairleads where fatigue concentrates, rather than simply totaling all broken wires over the full cable length. This localized concentration is a stronger fatigue indicator than a scattered total.
Why the other options are wrong
- A. Rejection criteria are based on concentration within a lay length, not a simple total over the whole cable.
- C. Wire color has no bearing on cable rejection criteria; this is a corrosion/wear assessment, not a color inspection.
- D. A single visible broken wire does not automatically mandate rejection depending on location and count.
Control Cable Broken Wire Rejection Criteria
AC 43.13-1B specifies cable rejection based on the number of broken wires counted within one cable lay length, with stricter limits near terminals, fittings, and pulleys where fatigue concentrates.
- Criteria vary by cable construction (e.g., 7x7 vs 7x19)
- Broken wires near end fittings are more critical than in free sections
- Cable should also be checked for corrosion, wear, and kinking
Memory trick: Count breaks 'per lay,' not the whole way