What is the Boeing 737 Max Manoeuvring Characteristics Augmentation System?

Boeing quietly added a new system “to compensate for some unique aircraft handling characteristics during it’s (sic) Part 25 certification” and help pilots bring the nose down in the event the jet’s angle of attack drifted too high when flying manually, putting the aircraft at risk of stalling, according to a series of questions and answers provided to pilots at Southwest Airlines, the largest 737 Max operator reviewed by The Air Current. The Maneuvering Characteristics Augmentation System (MCAS) was designed to address this, according to Boeing engineers and pilots briefed on the system, now at the center of the inquiry into the crash of Lion Air 610, a brand new Boeing 737 Max 8. The system can be deactivated if pilots trim the aircraft manually to override the MCAS’s attempt to automatically pitch the jet’s nose down.

Source: theaircurrent.com