This document discusses two plane crashes involving Lion Air Flight 610 and Ethiopian Airlines Flight 302, both of which involved Boeing 737 Max planes. It suggests that the crashes may have been caused by issues with the Manoeuvring Characteristics Augmentation System (MCAS), which was designed to automatically point the plane's nose down in certain conditions. However, MCAS relied on a single sensor and was not properly tested. The document argues that complex systems can reach a 'critical state' where small changes can lead to catastrophic failures, and that organizations like Boeing may undermine safety by not properly considering interactions within complex systems.