Which feature supports ADS data integrity by using multiple ADIRUs?

• A. Redundant ADIRUs provide cross-checks and data validation.
• B. Single ADIRU with manual backup.
• C. GPS-based data replaces ADIRU.
• D. Cabin pressure sensor substitutes for ADS.

Answer: (A)

Redundancy with multiple ADIRUs is what keeps ADS data reliable in flight. Each ADIRU provides the air data (airspeed, altitude, vertical speed) and inertial data (attitude). When several units operate, their outputs are continuously cross-checked against one another. If one unit starts drifting or failing, the system detects the mismatch, flags the fault, and can rely on the remaining correct units to determine the final values. This cross-checking and data validation preserve accurate flight data even in the presence of a fault, which is essential for automatic flight control and guidance.

The other approaches don’t provide the same automatic protection. A single ADIRU with a manual backup leaves potential data integrity gaps and introduces delays or human error in fault handling. GPS-based data can’t fully replace the ADIRU for critical air data and attitude information, and it isn’t as robust or independent as a dedicated, redundant ADIRU set. A cabin pressure sensor is unrelated to the air data and inertial information needed for ADS.