Plain English Meaning

The brain of the Flight Management System. It takes in position data from sensors and the route the pilot has entered, then works out where the aircraft is, where it should go next, and how to get there.

Full Definition

The central processing unit of a Flight Management System that integrates inputs from navigation sensors (GPS, VOR/DME, IRS), air data, and the pilot-loaded flight plan to compute the aircraft's position, route, performance data, and guidance commands sent to the autopilot, flight director, and cockpit displays.