Which Emergency Procedure is invoked when SFI attitude differs from the PFD attitude, or a Red X appears on SFI attitude, altitude, or heading?

Which Emergency Procedure is invoked when SFI attitude differs from the PFD attitude, or a Red X appears on SFI attitude, altitude, or heading?

• A. LPCAP Failure
• B. SFI Failure
• C. ICU Failure
• D. Hydraulic Indicating System Failure

Answer: (B)

When the standby flight instrument data conflict with the primary flight display, or a red X appears on the standby attitude, altitude, or heading, the data from the standby unit cannot be trusted. That fault mode is described by invoking the standby flight instrument failure procedure. The reason this is the best choice is that the SFI is the backup reference for attitude, altitude, and heading; a mismatch or invalid indication means the standby instrument is unreliable, so you switch to the procedure that handles that failure and rely on the other valid references (primarily the PFD and other flight instruments) to maintain safe flight. The other options relate to different systems entirely (LPCAP, ICU, hydraulics) and do not address a fault or invalid indication on the standby flight instrument.

When the standby flight instrument data conflict with the primary flight display, or a red X appears on the standby attitude, altitude, or heading, the data from the standby unit cannot be trusted. That fault mode is described by invoking the standby flight instrument failure procedure. The reason this is the best choice is that the SFI is the backup reference for attitude, altitude, and heading; a mismatch or invalid indication means the standby instrument is unreliable, so you switch to the procedure that handles that failure and rely on the other valid references (primarily the PFD and other flight instruments) to maintain safe flight. The other options relate to different systems entirely (LPCAP, ICU, hydraulics) and do not address a fault or invalid indication on the standby flight instrument.