Drew Griffin at CNN has published a new investigative report that has revealed that one day after the Ethiopian minister of transportation made a preliminary report on the crash of Ethiopian Airlines flight 302 public, four existing and four ex-employees of Boeing made contact with the US Federal Aviation Authority’s anonymous safety hotline. These calls were made for reporting additional problems with the aircraft.
As per the CNN report, the four safety reports were pertinent to the MCAS autopilot system, and a component sensor that is affixed on the exterior of the plane and is used for measuring the angle of attack of the aircraft. The MCAS autopilot system is already being suspected for the two crashes of a Boeing 737 MAX 8 within a time span of five months, and killing 346 persons in total.
The FAA has given confirmation to the CNN that it did receive such reports on the anonymous safety hotline and that the calls could be the reason why another line of investigation is opened up into Boeing’s 737 MAX 8 aircraft. It should be noted that the Boeing 737 MAX 8 aircraft has been grounded ever since the Ethiopian Airlines flight 302.
According to one whistleblower, damage to the electrical wiring connected to the sensor responsible for the angle of attack by providing the data to the MCAS system, from a foreign object was observed. MCAS system uses this data to prevent the plane from stalling. This won’t be the first time that Boeing has failed to prevent components of its planes getting damaged from foreign objects during the fabrication process.
Why this new report matters? Because according to the preliminary report of the Ethiopian Airlines crash investigation, the MCAS system had bad data and that led to the system believing that it was in danger of stalling out. The corrective response that forces the rise of the tail also forces the nose of the plane down. For the Ethiopian Airlines flight 302, the pilots kept on attempting to win the war against the MCAS system but eventually ended up crashing.
Documents have also shown that the Boeing safety inspectors didn’t completely comprehend or misrepresented the strength of the new MCAS system while preparing the safety review for the plane prior to certification. They did not classify the failure of this system as a catastrophic failure as well. It is the highest possible classification indicating that such a failure will lead to the deaths of everyone onboard. Instead, they classified it as a severe failure, a lower classification that doesn’t imply that the system must feature an additional sensor to feed the data into the system.
The Boeing 737 MAX 8 aircraft already features two angle of attack-sensors, but the system was designed to pick up readings from only one of the sensors. We will have to wait for a full investigation report to come out in order to learn what really happened and how it can be prevented in the future.