Final answer:
An amber FAULT light in the APU BLEED pb indicates a malfunction within the APU bleed air system, which could involve issues with air pressure, temperature, or the control box, and would require further troubleshooting per the aircraft's manual.
Step-by-step explanation:
When you see an amber FAULT light in the APU BLEED pushbutton (pb), it indicates a malfunction in the Auxiliary Power Unit (APU) bleed air system. The APU is a device on aircraft used primarily during ground operations to provide electrical power and pneumatic pressure for various systems when the main engines are not running. The APU bleed air is essential for environmental control systems and engine starting. The amber FAULT light signals to the pilot or maintenance crew that there is an issue with the bleed air pressure or temperature, or with the electronic control box.
Typically, when an APU BLEED FAULT is indicated, the crew must refer to the aircraft's operating manual for proper troubleshooting procedures. They must ensure the safety and readiness of the aircraft before the next operation. The warning may require immediate attention to prevent further complications or system failures.