What is the role of a standby attitude indicator and when is it used?

• A. It provides attitude reference during EFIS/AHRS failure; used as a backup instrument.
• B. It is the primary attitude source during normal operations.
• C. It only displays heading information.
• D. It measures airspeed.

Answer: (A)

Standby attitude indicator provides an independent attitude reference that stays available if the main attitude source (EFIS/AHRS) fails or becomes unreliable. It uses its own gyro and often an independent power source, so it isn’t affected by the loss of the primary system. It shows the aircraft’s pitch and bank relative to the horizon, giving you a reliable reference to maintain control in IFR or during electrical failures. It’s used specifically as a backup when the primary attitude information is unavailable, not as the normal primary attitude source during standard operations. It does not display heading and it does not measure airspeed, so you’d still rely on separate instruments for those parameters.