If the standby attitude gyro off flag appears after the battery bus fails, how long will the indicator operate?

When the standby attitude gyro off flag appears after a failure of the battery bus, it indicates that the gyro is no longer receiving its electrical power supply, which is vital for its function. However, the standby attitude gyro is designed to operate on internal power for a limited duration after such a failure. This internal power typically allows the gyro to function for a predefined timeframe before it runs out.

The correct answer reflects the standard operational limitation of the standby attitude gyro, which is 9 minutes in this scenario. During this 9-minute window, the gyro can still provide essential attitude information to the pilot, which is critical for maintaining control of the aircraft in the event of a primary instrument failure. After this period, the gyro will no longer function, and pilots must rely on any remaining backup systems or alternative instruments available to navigate and maintain safe flight operations. Understanding this limitation is crucial for pilots to ensure they can act promptly in emergencies.