Which shielding coverage percentage is recommended for shielding used on aircraft cables?

Which shielding coverage percentage is recommended for shielding used on aircraft cables?

• A. 70%
• B. 95%
• C. 100%
• D. 85%

Answer: (D)

Shielding coverage tells you how much of the cable’s circumference is wrapped by shielding material. For aircraft cables, an 85% shielding coverage is the recommended minimum because it provides a solid barrier against common EMI without making the braid stiff or costly. Gaps in shielding at lower percentages (like 70%) can allow EMI to couple into the conductors, while higher coverage (95% or 100%) offers more shielding but isn’t usually needed and can reduce flexibility and increase cost. In practice, about 85% gives a reliable balance of effective shielding with good mechanical properties.

Shielding coverage tells you how much of the cable’s circumference is wrapped by shielding material. For aircraft cables, an 85% shielding coverage is the recommended minimum because it provides a solid barrier against common EMI without making the braid stiff or costly. Gaps in shielding at lower percentages (like 70%) can allow EMI to couple into the conductors, while higher coverage (95% or 100%) offers more shielding but isn’t usually needed and can reduce flexibility and increase cost. In practice, about 85% gives a reliable balance of effective shielding with good mechanical properties.