Which data interface is a high-reliability avionics data bus used to transport navigation data like position, velocity, and attitude?

• A. NMEA 0183.
• B. NMEA 2000.
• C. ARINC 429/664.
• D. CANopen.

Answer: (C)

Navigation data in aircraft need to move with strict reliability and predictable timing. ARINC 429 and ARINC 664 are designed exactly for that role in aviation networks. ARINC 429 provides a structured, standardized way to send navigation-related data as 32-bit words over a dedicated bus, with provisions for redundancy and deterministic delivery so position, velocity, and attitude information arrives where it’s needed without ambiguity. ARINC 664 takes this forward with Avionics Full-Duplex Switched Ethernet, offering higher data rates and robust, fault-tolerant networking suitable for modern, avionics-wide data sharing.

The other interfaces are not typically used as the high-reliability nav data bus in aviation. NMEA 0183 and NMEA 2000 originated for marine use and are slower or not certified for certified aircraft networks. CANopen is a general-purpose fieldbus not specialized for aviation’s stringent reliability and real-time requirements.