Some of the most upsetting disasters (in the sense of how avoidable they should have been) have been caused by failures of the human-machine interface, particul

Some of the most upsetting disasters (in the sense of how avoidable they should have been) have been caused by failures of the human-machine interface, particularly with automation. For example https://en.wikipedia.org/wiki/Emirates_Flight_521 https://en.wikipedia.org/wiki/Emirates_Flight_521 - a go around was commanded by the pilots to abort a landing, but they weren't aware that the automated go around system - specifically the auto-throttles - would not engage if the wheels had touched the ground (if only briefly). Thus engine power remained at idle/landing speed, and the plane fell out of the sky. The pilots should have checked the throttles of course, but they would not necessarily have been aware that the wheels had touched down, may not have known/remembered that the automatic go around system would not function in that case, and they were concentrating on flying the plane in presumably unusual circumstances that led to the go around in the first place - they assumed the automation would function as it usually does. A better human-machine interface (e.g. with a warning that go around automation was disabled) would have prevented the crash. I think anyone designing human-machine interfaces, especially safety critical systems, should read up on these cases.