The MCAS system works by automatically adjusting the aircraft's trim, which is the angle at which the aircraft's wings are set. When the aircraft is in danger of entering a stall, the MCAS system will automatically lower the aircraft's nose, forcing it to fly at a higher speed and preventing the stall from occurring.
The MCAS system is activated by a sensor that detects when the aircraft is in danger of entering a stall. The sensor measures the angle of attack, which is the angle between the aircraft's wings and the oncoming air. When the angle of attack exceeds a certain threshold, the MCAS system will activate.
The MCAS system is a controversial system, and has been implicated in two fatal crashes of Boeing 737 MAX aircraft. In the Ethiopian Airlines Flight 302 crash, the MCAS system is believed to have malfunctioned, causing the aircraft to enter a stall and crash. In the Lion Air Flight 610 crash, the MCAS system is also believed to have malfunctioned, causing the aircraft to enter a stall and crash.
Following these crashes, Boeing has made changes to the MCAS system to make it less aggressive and to provide pilots with more control over the system. The MCAS system is now required to be disabled if the aircraft's angle of attack exceeds a certain threshold. Pilots can also manually override the MCAS system by pulling back on the control yoke.
The MCAS system is a complex system, and it is still under investigation by aviation authorities around the world. It remains to be seen whether the changes made by Boeing will be sufficient to prevent future accidents.
