How is a fuel leak typically detected and addressed on a narrowbody?

• A. Visual signs or fuel odor, fuel quantity anomalies, and inspection/repair of affected lines or seals; isolate source and perform repairs.
• B. Only rely on a fuel quantity gauge.
• C. Ignore minor leaks and continue to destination.
• D. Replace the fuel lines during flight.

Answer: (A)

Fuel leaks are identified by a combination of observable signs and system indicators, then managed by stopping the leak at its source and performing the necessary repair.

In practice, you’d look for visual signs such as dampness or pooling around fuel lines, fittings, or wing areas, and you’d notice the odor of fuel in or around the airplane. Fuel quantity indicators may also show an unexplained drop that can’t be explained by normal consumption. When a leak is suspected, the proper response is to isolate the source by securing the relevant fuel path and shutting off the affected line or valve to stop the flow, then arrange for inspection and repair of the leaking line or seal. This keeps fuel from continuing to escape and reduces fire risk while maintenance addresses the exact failed component.

Relying solely on a fuel quantity gauge isn’t reliable for detecting all leaks, and attempting to ignore leaks or replace lines during flight isn’t feasible or safe. After maintenance fixes, a careful post-repair leak check is performed before restoring normal operation.