Minutes after takeoff, the pilots of an Ethiopian Airlines 737 Max were caught in a bad situation.
A key sensor had been wrecked, possibly by hitting a foreign object, according to four aviation experts and two U.S. officials who were briefed on the flight data.
As soon as the pilots retracted the flaps and slats, according to flight data, the sensor began to feed faulty information into the Maneuvering Characteristics Augmentation System (MCAS), designed to prevent stalls.