On March 10, 2019, flight 302 Ethiopian Airlines connecting Addis Ababa crashes six minutes after takeoff. The 157 occupants of the aircraft, a Boeing 737 Max 8, were killed instantly, making it the deadliest accident in the history of Ethiopian Airlines as well as the deadliest one in Ethiopia.
This is the second accident involving the Boeing 737 Max, the first is the crash of the Lion Air 610 flight in October 2018 occurred under similar conditions thirteen minutes after take-off, resulting in three days later the suspension of flight the Boeing 737 Max in 2019.
ECAA is responsible for investigating the accident, in association with the US NTSB, due to the nationality of the builder, Boeing. The day after the accident, the two flight recorders were recovered. As Ethiopia does not have the equipment to read black boxes, both flight recorders (FDR and CVR) were sent to France. They arrive on March 14th at the BEA, which successfully extracts the data with the participation of ECAA and NTSB.
The similarities with the crash of the Lion Air 610 flight cast doubt on the computer system stabilization introduced on the 737 MAX, the MCAS (Maneuvering Characteristics Augmentation System), supposed to avoid stall but which, when it gives erroneous information, can act wrongly on the horizontal stabilizer and sting the plane. In fact, the cylinder that controls this stabilizer has been found in position to stitch. On 17 March, after analysis of the black boxes, the Ethiopian Minister of Transport confirms the similarities between the two accidents.
The first elements of the survey were published Thursday, April 4 and they clarify some points. « The report dismisses any human error in the crash of the plane, the pilots have followed the emergency procedures put in place by Boeing and validated by US civil aviation, but fail to regain control of the aircraft ».
The pilots had a short window to react before going into an irrecoverable nosedive. Tests of the 737 Max have shown that once faulty data triggered the system, pilots had little time to save the aircraft. The system, according to the investigators findings, appears to have forced the nose of the plane down several times in less than three minutes.
After two successive crashes of the same airplane model “Boeing 737 MAX”, and after the planes were suspended from flying, Boeing presented a new version of its flight system Wednesday, implicated in two accidents, in order to fly again 737 MAX grounded since mid-March. In fact, Boeing has modified its anti-stall system known as the Maneuvering Characteristics Augmentation System (MCAS). The manufacturer has installed this program on its 737 MAX devices to prevent the aircraft from pitching and falling (stall) for lack of lift.
In addition to this, To have a flight certification on 737, pilots must follow 21 days or more of courses and simulator flights under the supervision of an instructor. The Boeing 737 MAX will also be equipped with a signal light to warn of any malfunction of MCAS. Until now it was a paid option; it will be free now. This signal will be triggered in case of erroneous information transmitted by one or two incidence probes.
To conclude, even with this mechanical imperfection Boeing will always be the best aircraft manufacturer in the world.