An off-duty pilot in the cockpit of a Boeing 737 Max 8 jet jumped in to help crew disable a malfunctioning flight-control system as it experienced difficulties in October, according to Bloomberg.
The next day, with a different crew, the same plane crashed into the sea off Jakarta, killing all 189 people on board.
Investigators said the jet experienced problems on its last four flights -- including, crucially, the flight that crashed,
Indonesian authorities confirmed that the plane's angle of attack (AOA) sensor was replaced after a flight from Manado, in North Sulawesi to Denpasar, Bali on October 28. The Boeing 737 Max 8 then made another flight to Jakarta that same day, and the pilots reported further problems.
The AOA sensors send information to the plane's computers about the angle of the plane's nose relative to the airflow over and under the wings to help determine whether the plane is about to stall.
Software installed on Boeing's 737 Max 8 planes, called the Maneuvering Characteristics Augmentation System (MCAS), automatically lowers the nose of the plane when it receives information from the AOA sensors that the aircraft is flying too slowly or steeply, and at risk of stalling.
A preliminary KNKT report said the crew of Air Lion Flight 610 struggled to override the plane's automatic systems in the minutes before it plunged into the ocean. The system pulled the plane's nose down more than two dozen times, the report said.
This has been happening for months. Years? And if the crew knows how to turn it off the outcome is good. If not...