Autopilot could make pilots rusty, DOT says

After recent incidents including the crash of Asiana Airlines flight 214 in 2013, the U.S. Department of Transportation released an audit report, saying overuse of flight automation could be hazardous. The report suggests that while advancements in automation have improved flight safety, "pilots who typically fly with automation can make errors when confronted with an unexpected event or transitioning to manual flying."

And flying with automation is incredibly common; The Federal Aviation Administration estimates that automation is used 90% of the time in flights.