did not tell Southwest Airlines
, its largest 737 Max customer, that a standard safety feature designed to warn pilots about malfunctioning sensors had been deactivated on the jets.
The safety feature is an alert that lights up in the cockpit if a plane’s angle-of-attack sensors transmit faulty data about the pitch of the plane’s nose. This feature is known as an angle-of-attack disagree light and was included in previous versions of the 737.
Southwest did not know about the change until after the fatal crash of a Lion Air flight in Indonesia. The airline, in a statement to CNBC, said Boeing had indicated through its manual that the disagree lights were functional on the 737 Max.
Southwest said Boeing told the airline that the disagree lights were inoperable only after the Lion Air crash. The airline subsequently took action to turn the alerts on.