U.S. Sen. Tammy Duckworth (D-IL) sent a letter to Acting Federal Aviation Administration (FAA) Administrator Daniel Elwell this week urging the FAA to publish a set of standardized best practices.
The practices would ensure airlines and flight crews comply with federal safety standards and regulations.
The letter is in response to multiple incidents involving faulty or malfunctioning angle of attack (AOA) sensors on airplanes. Erroneous data from AOA sensors contributed to the crashes of two Boeing 737 MAX series jets and also lead to the grounding of all Cirrus SF50 Vision Jets.
“A recent FAA emergency airworthiness directive (AD) issued on April 18, 2019, demonstrates the dangers of malfunctioning AOA sensors,” Duckworth wrote in the letter. “This AD was necessitated by a manufacturing flaw in the torqueing of set screws that secure the potentiometer shaft to the AOA vane shaft and the failure to apply thread locker to secure the set screws. It noted that the AOA sensor flaw could result in unintended automatic flight control activations; difficulty controlling the aircraft; excessive nose-down attitude and possible impact with terrain.”
Duckworth urged the FAA to issue best practices for the manufacture, operation, testing and maintenance of AOA sensors, particularly the AOA wind vane component that is located on the aircraft’s exterior.