There has been a lot of speculation that the MCAS system, which was cited as a contributing factor to the Lion Air crash, was also a potential factor in the crash of Ethiopian 302. At this point in time, however, we really don’t know what caused ET302 to go down, and need to wait for BEA and the multi-national investigation team to determine the cause for the accident.
Until we know the answer, it is inappropriate to place the 737MAX back into service, particularly if it turns out that something other than MCAS contributed to the crash. We simply don’t know the answers as yet, and unfortunately, investigation and reconstruction of the circumstances of the crash will be neither fast or and easy task. These things take time.