FAA Powerplant Written Practice Test

When installing electrical wiring parallel to a fuel line, where should the wiring be positioned?

1. Above the fuel line

2. Below the fuel line

3. Alongside the fuel line

4. Directly beside the fuel line

The correct answer is: Above the fuel line

Positioning electrical wiring above the fuel line is recommended to minimize the risk of accidental damage and to avoid potential ignition sources in the event of a fuel leak. By running the wiring above, gravity assists in keeping the wiring away from the fuel line, which can reduce the likelihood of electrical faults occurring due to contact with fuel or in the presence of fuel vapors. When electrical wiring is placed below or directly alongside a fuel line, it increases the risk of exposure to leaks or spills. In the event of a fuel leak, having the wiring positioned above ensures that any liquid that may escape from the fuel line does not pool on the wiring, which could create a hazardous situation by promoting a short circuit or electrical fire. Following this standard practice enhances safety in aircraft electrical systems, ensuring that both fuel and electrical components can operate without interference or risk to one another.