In the event of an attitude and heading reference system failure, what becomes your primary pitch instrument?

In the event of an attitude and heading reference system (AHRS) failure, the primary pitch instrument you would rely on is the PFD altimeter. This is because the altimeter provides crucial information about your vertical performance, which is critical for maintaining controlled flight and ensuring safe altitude levels.

The altimeter measures the aircraft's altitude relative to sea level, and during an AHRS failure, pilots must rely on this data to manage their ascending and descending actions effectively. By maintaining awareness of altitude changes, pilots can ensure they are avoiding terrain and other obstacles, as well as staying compliant with air traffic control instructions.

While other instruments such as the vertical speed indicator or airspeed indicator can provide additional context regarding the aircraft's vertical movement and performance, they do not serve as the primary indicator for managing pitch. The vertical speed indicator may indicate how quickly you are climbing or descending, but it does not give a direct altitude reading like the altimeter does. Therefore, when faced with an AHRS failure, pilots must look to the altimeter for essential pitch information to safely navigate and maintain altitude.