Which system is NOT part of the integrated avionics system?

• A. Radio navigation system
• B. Navigation display (NAV)
• C. Backup flight instrument (BFI)
• D. Primary flight display (PFD)

Answer: (C)

Integrated avionics brings navigation, flight data, and displays onto a single data network, so components like the radio navigation system and the navigation display work together to provide accurate guidance on-screen. The primary flight display also relies on that shared data to show attitude, airspeed, altitude, and other essential information. The backup flight instrument, on the other hand, is designed as an independent standby system with its own power and sensors, intended to remain reliable if the main avionics falter. Because it isn’t integrated into the main data bus and display suite, it isn’t considered part of the integrated avionics system.