How is an AGM failure typically identified during operation?

An AGM (Attitude and Heading Reference System) failure is typically identified during operation by observing red Xs on both display units. This visual indicator signals a critical malfunction within the system that affects the aircraft's attitude and navigation references. When the AGM is working correctly, it provides essential data to the flight instruments – any failure would result in a clear indication that something is wrong, often represented by these red Xs, prompting immediate attention from the flight crew. This method of identification is crucial for maintaining situational awareness and ensuring the safety of the operation, as it alerts pilots to a reliance on backup systems and reinforces the need to adhere to emergency procedures in such situations.

The other possible indicators, while related to various aircraft systems, do not specifically correlate with AGM failure. A loss of altitude, display flickering, or engine vibrations could be attributed to different issues or malfunctions, making red Xs a definitive sign tied directly to AGM problems.