An acceptable installation distance above the fuel line for aircraft wiring is?

An acceptable installation distance above the fuel line for aircraft wiring is?

• A. 2 inches
• B. 6 inches
• C. 4 inches
• D. 8 inches

Answer: (B)

Keeping wiring separated from fuel lines is essential to reduce the risk of ignition from any leaked fuel vapor and to protect insulation from potential fuel exposure. The standard minimum vertical clearance above a fuel line is six inches. This distance provides a safe margin so that gasoline vapors, which can accumulate in lower areas, are unlikely to reach or wick into wiring or its insulation, even if a leak occurs. If the wiring were too close, a small fuel leak could bring vapors into contact with electrical components or arcing, increasing the chance of ignition. If six inches cannot be maintained, alternate routing or shielding is required to preserve a safe separation.

Keeping wiring separated from fuel lines is essential to reduce the risk of ignition from any leaked fuel vapor and to protect insulation from potential fuel exposure. The standard minimum vertical clearance above a fuel line is six inches. This distance provides a safe margin so that gasoline vapors, which can accumulate in lower areas, are unlikely to reach or wick into wiring or its insulation, even if a leak occurs. If the wiring were too close, a small fuel leak could bring vapors into contact with electrical components or arcing, increasing the chance of ignition. If six inches cannot be maintained, alternate routing or shielding is required to preserve a safe separation.