Plain English Meaning

A small box of electronic sensors that figures out which way the aircraft is pointing — nose up or down, banked left or right, and what direction it is heading — and sends that information to the cockpit displays.

Full Definition

An electronic system of solid-state sensors — typically three-axis accelerometers, gyroscopes, and magnetometers — that continuously measures the aircraft's orientation in space and feeds that data to electronic flight displays. It provides pitch, roll, yaw, and magnetic heading information, replacing the spinning mechanical gyroscopes used in traditional attitude indicators and .