Ethiopian Airlines crash: What is the MCAS system on the Boeing 737 Max 8?
https://phys.org/news/2019-03-ethiopian-airlines-mcas-boeing-max.html
Both the Lion Air jet, which crashed in October, killing 189 people, and the Ethiopian Airlines aircraft, which went down on Sunday, leaving 157 people dead, were fitted with the system.
Both planes experienced similarly erratic steep climbs and descents and fluctuating airspeeds before crashing shortly after takeoff.