Seems to me that redundancy in mission critical systems where failure means loss of several hundred lives is a basic engineering principle. MCAS apparently rel

Seems to me that redundancy in mission critical systems where failure means loss of several hundred lives is a basic engineering principle. MCAS apparently relied on a single AOA sensor's input. The system had no way to validate the data or handle a mismatch, and the only recourse was to light up an (optional) disagreement indicator - but still relied on just the one sensor to apply control forces.