All electronics can fail, and those failures can be unpredictable. A bad batch of capacitors can pop during the slightest surge of current. Age can also contrib

All electronics can fail, and those failures can be unpredictable. A bad batch of capacitors can pop during the slightest surge of current. Age can also contribute. Car ECUs used to be built to be as simple as possible (which also cuts down on manufacturing costs) - this had the nice side effect of making them extremely reliable. And if they fail, it's an inconvenience, but rarely life-or-death. Autopilot systems, however, are only as good as the people who program them. A helicopter, as mentioned elsewhere, is dynamically unstable and requires so many tiny inputs to maintain steady flight, let alone hovering. Just like in Teslas that 'nope' out of their Autopilot systems back to the driver milliseconds before a crash, a pilot has precious little time to retake control should the electronics fail. Car ECU keeping your car moving in one dimension (forwards) - fairly safe to let a computer take over, minimal danger if it fails. Autonomous technology keeping your car moving in two dimensions (forwards AND steering) - very complex, very little time to retake control in a failure scenario, very dangerous. Autopilot keeping your helicopter moving in three dimensions - I think you get the idea by now :)