It is on the Airbus, one of the control laws, see link above. It's still FBW though, so one might argue that "mechanical backup" is really what you want. As fo

It is on the Airbus, one of the control laws, see link above. It's still FBW though, so one might argue that "mechanical backup" is really what you want. As for "modern", the A320 had control laws in 1984 and the 777 in 1994.