Automatic Direction Finding (ADF).

A basic guidance mode, providing lateral guidance to a radio station. Equipment that determines bearing to a radio station; Automatic flight control system (AFCS). An automated system for controlling the primary flight controls, often with built-in functions for guidance and flight director, and sometimes radio navigation; many flight control systems include basic instruments similar to a AHRS; many flight control systems accept flight director inputs so that its radio navigation, guidance, and flight director can be bypassed