If the PDU overheats, what happens?

• A. The circuit breaker will trip and can be reset after about 5 minutes
• B. Flaps deploy automatically
• C. Hydraulic pressure is lost
• D. Autopilot disengages

Answer: (A)

When the Power Distribution Unit (PDU) overheats, its protective thermal mechanism trips a circuit breaker to isolate the PDU and prevent damage. That breaker is resettable, but it must cool before you can reset it, typically after about five minutes. This is to ensure the unit isn’t hot enough to cause immediate re-overheating or damage once power is restored.

The other options don’t fit because flap deployment, hydraulic pressure loss, or autopilot disengagement aren’t direct consequences of the PDU overheating. Flaps, hydraulics, and the autopilot are controlled by separate systems, and overheating the PDU wouldn’t automatically trigger those actions.