• The Lion Air crash ... which started the 737 MAX controversy

    From Aviation HQ@2:292/854 to All on Fri Oct 25 16:51:35 2019
    The accident of the Boeing 737 MAX of Lion Air in October 2018 was caused by a combination of a technical defect and design errors. This is apparent from a briefing given by Indonesian investigators to the families of the victims, in anticipation of the presentation of the final report.

    As previously reported, unreliable data from an angle-of-attack sensor triggered the new and unknown Maneuvering Characteristics Augmentation System (MCAS).

    The sensor that was linked to the MCAS was recently repaired but not properly calibrated. The fact that the MCAS was linked to only one angle-of-attack sensor made the system vulnerable in the event of technical failure, as was the case uring the ill-fated Lion Air flight.

    The researchers also found that the design and certification of the 737 MAX did not properly assume how the MCAS functions and how pilots would react when the system was activated. A lack of training for 737 MAX pilots made it extra difficult to solve the problems.

    Due to the malfunctioning angle-of-attack sensor, the MCAS mistakenly thought that the aircraft ascended too steeply and ended up in a stall. This was "corrected" by pushing down the nose of the aircraft. Repeated attempts by the pilots to push the nose up again ultimately yielded nothing, causing the aircraft to crash into the Java Sea. All 189 passengers were killed.

    According to Reuters, slides that researchers showed to relatives also showed that there was not enough documentation available about how systems would behave in a scenario such as occurred on flight JT610. The pilots were also distracted by "shortcomings" in manual operation of the aircraft and communication.

    In March this year, a Boeing 737 MAX 8 from Ethiopian Airlines crashed under similar circumstances as flight JT610. Shortly thereafter, a worldwide flight ban was introduced for the 737 MAX. Boeing has developed a series of design adjustments that are still awaiting certification. It is not yet known when the 737 MAX fleet will be able to fly again.

    Due to the problems with the 737 MAX, aircraft manufacturer Boeing is under a magnifying glass. The company has set aside billions of dollars for damages to relatives and customers. It has also been found that the American aviation authority FAA mismanaged the certification of the 737 MAX.

    --- D'Bridge 3.99
    * Origin: AVIATION ECHO HQ (2:292/854)