The data on the black box of the doomed Ethiopian flight Airlines suggest that the crash was caused by a defective sensor that erroneously activated the Boeing 737 Max automated system, a series of similar events suspected of an Indonesian disaster involving the same plane last year
Data from a blade-like device called the angle-of-attack sensor incorrectly activated the computer-controlled system, according to three people who were aware of the contents of the black box in Ethiopia. It is believed that the system, known as MCAS, has pushed the nose of the plane, which has led to the irretrievable nose dive, which killed all 1
The black box, also called a flight data recorder, contains information about dozens of systems on board the aircraft. The black boxes of the two aircraft, the latest generation of Boeing of 737, survived the catastrophe, allowing investigators to begin to collect the causes of the disasters together. Both investigations are ongoing and no final decisions have been made.
The new connections between the two crashes contribute to the pressure on Boeing, which is subject to control over the design and certification of the aircraft. Boeing plays a major role in the approval of the 737 Max, as regulators delegate considerable responsibility and oversight to the manufacturer.
Airplane design and certification is the subject of many government inquiries. The Ministry of Justice is investigating the development of the aircraft and the General Inspector of the Transport Department is examining the certification process. The Inspector General has issued a summons to at least one former Boeing engineer for documents related to 737 Max, according to a person familiar with the investigation.
The MCAS was originally designed to be activated on the basis of data from a single angle of an attack sensor that measures the level of the nose of the jet to the moving air. Air safety experts, as well as former Boeing employees and the supplier who produced the sensor, have expressed concern that the system has this single point of failure, a rare occurrence in aviation.
Such sensors are very reliable and have been used on passenger planes for years, but as each component of the plane, they can fail, engineers said. Since the sensor is wrong, it is surprising that Boeing has allowed himself to activate a system that automatically pushes the plane to the ground, said a former engineer who helped build sensors at Rosemount Aerospace, a subsidiary of industrial giant United Technologies.
In silent recognition that the original design is inadequate, Boeing introduced a software update this week that will make the system rely on both sensors instead of just one. If the two sensors disagree with a certain amount, MCAS will not commit.
Boeing said he could not comment on the black box's findings until the investigators issued their official report on international aviation agreements. The United Technologies spokeswoman did not respond immediately to the requests for comments.
Sensors, which are actually wind turbines on the engine nose, have not worked in the past for various reasons, including blows to birds, according to former engineers. in Boeing and Rosemount. They have also been broken down by road arteries that are attached to the plane to allow passengers to board and leave the plane. The sensors have built-in heaters to prevent freezing at such high altitudes, but sometimes they do not work fast enough or can fail, said the Rosemount engineer. the information from the case, saw that a sensor produces a reading that is at least 20 degrees different from the other when the plane is out and starts climbing. With bad data, MCAS was activated, mistakenly pushed the airplane's nose.
The pilots of the Indonesian flight have repeatedly tried to overcome the system. But in about 12 minutes they lost their battle and the plane crashed. But the same bouncy trajectory of the plane seen in the Indonesian flight when the pilots tried to save the plane was evident in the publicly available flight data for the Ethiopian aircraft. before the plane crashes. The pilot went back to having problems controlling the plane, but did not give details of what systems are causing problems.