Which of the following is a common indicator of a generator (alternator) failure in flight?

• A. Voltage regulation loss
• B. Engine RPM drop
• C. Cabin pressurization issue
• D. Decreasing fuel flow

Answer: (A)

When a generator fails, a primary symptom is loss of voltage regulation. The generator’s regulator keeps the output voltage within a specific range to match the aircraft’s electrical system. If that regulator stops working properly, the generator can no longer hold voltage steady, causing abnormal voltages on the electrical buses and often triggering a fault warning. This is a direct, diagnostic sign of generator health impacting the system’s ability to receive consistent power.

Other options point to issues outside the electrical generating unit: engine RPM drop signals engine power loss, cabin pressurization relates to the environmental control and air system, and decreasing fuel flow is an engine/fuel system symptom.