automatic pilot

Từ điển Việt Anh Việt 4in1 - English Vietnamese 4 in 1 Dictionary

ˌautomatic ˈpilot BrE AmE noun [uncountable and countable]
1. a machine that flies a plane by itself without the need for a pilot
2. on automatic pilot doing something without thinking about it, especially because you have done it many times before:
Moving on automatic pilot, she tidied the room.