Panasonic CY-111VB | Cylindrical Photoelectric Sensor CY-100 SERIES
Patent: Methods and systems for jet engine overthrust protection
"A method for sensing and reacting to jet engine fan speed in excess of a fan speed computed from an aircraft throttle input is disclosed. Engine fan speeds are detected by adding test conditions to a main central processing unit (CPU) and adding test conditions to an independent overspeed module to provide additional protection from main CPU computational errors. Interpretation of sensor data relating to engine speed may initiate a modeling routine for sensor data. Comparison of measured/computed sensor data to desired conditions using logic and data tables is a used. If an anomaly is detected, engine fuel cutback devices are engaged."