One day after denying any risk with the aircraft, FAA and Boeing determined that all 737 MAX still in operation will be grounded temporarily. The measure, however, was only taken after the US government ordered the civil aviation agency to follow the same procedure as that adopted by several countries.
“The agency made this decision as a result of the data gathering process and new evidence collected at the site and analyzed today.” This fact, together with newly refined satellite data available to FAA this morning, led to this decision,“explained the FAA in statement released a moment ago.
At the same time, Boeing, while still claiming that the 737 MAX is safe, admitted that “after consultation with the US Federal Aviation Administration (FAA), the US National Transportation Safety Board (NTSB), and aviation authorities the world, Boeing has determined – out of an abundance of caution and in order to reassure the flying public of the aircraft ‘s safety – to recommend to the FAA the temporary suspension of operations of the entire fleet of 371 737 MAX aircraft.”
The order affects not only American Airlines and Southwest Airlines, which operate the 737 MAX 8 model, but also United Airlines, which uses the 14 jets MAX 9, version of more capacity.
The resistance of the FAA and Boeing to being more cautious was criticized by American congressmen who pressured Donald Trump to take action. The US president spoke on Wednesday with FAA Director Daniel Elwell, Transportation Secretary Elaine Chao and Boeing Chief Executive Denis Muilenburg when it was decided that the 737 MAX should be grounded.
MCAS, the villain?
The suspicion that something is wrong with the 737 MAX’s flight control software was reinforced after the Ethiopian crash on Sunday. While there are still details on what happened to the aircraft after takeoff, some similarities to the Lion Air crash in 2018 impress. In both cases, the planes crashed minutes after takeoff and apparently in a sharp dive.
After analyzing the investigation with the 737 MAX Indonesian, Boeing decided to modify the MCAS (Maneuvering Characteristics Augmentation System), an automatic system that helps the crew to lower the nose of the plane in case of high angle of attack. This software upgrade is scheduled to take place in the coming weeks, Boeing said, but it would be unrelated to the crash in Africa.
The MCAS was a solution to compensate for the tendency to lift the nose in some 737 MAX flight situations. To make the plane more economical, Boeing needed to change the position of the engines, which are larger than before. The solution was to move the engine to a higher position and to raise the landing gear by 8 inches, but the effect of this change was that there were instability in certain flight profiles. Reports from US pilots claim that the 737 MAX exhibited strange behavior after takeoff, with the autopilot on.
More than ever, we must understand what happened with the 737 MAX from Ethiopian Airlines.