Boeing said Sunday that it discovered after airlines had been flying its 737 Max plane for several months that a safety alert in the cockpit was not working as intended, yet it didn't disclose…
The feature was designed to warn pilots when a key sensor might be providing incorrect information about the pitch of the plane’s nose.
But within months of the plane’s debut in 2017, Boeing said, its engineers realized that the sensor warning light only worked when airlines also bought a separate, optional feature.
The sensors malfunctioned during an October flight in Indonesia and another in March in Ethiopia, causing software on the plane to push the nose down. Pilots were unable to regain control of either plane, and both crashed, killing 346 people.