Final answer:
An IDG FAULT light indicates a malfunction in an aircraft's Integrated Drive Generator (IDG) system, which could include overheating, oil pressure issues, or control unit failures, and requires immediate attention.
Step-by-step explanation:
An IDG FAULT light typically indicates a problem with the Integrated Drive Generator (IDG) system on an aircraft. This system is responsible for converting engine power into electrical power. When this light illuminate, it alerts the pilot or maintenance crew that there has been a malfunction within the generator or its control systems, such as an overheat, a differential in oil pressure, or a failure in the generator control unit.
It is essential for the flight crew to address an IDG fault promptly. Depending on the aircraft's redundancy systems and the nature of the issue, this might involve procedures such as disconnecting the IDG and relying on an Auxiliary Power Unit (APU) or a backup generator for electrical power until the issue can be resolved. Therefore, it is critical for maintaining the aircraft's electrical systems' reliability and safety in flight.