During its investigation of the Atlantic Southeast Airlines flight 529 accident,
64 the Safety Board determined that the EMB-120’s two flight control position sensors had malfunctioned, preventing the required data from being accurately recorded, and that the lack of data hindered the investigation. The Board’s report on the accident noted that tests could be conducted to ensure timely identification and repair of potentiometer
malfunctions, including FDR parameter readouts. The report also noted that malfunctions
that occur between readouts are typically not detected.