Plain English Meaning
A specific brand and model of flight computer, made by Universal Avionics, that handles navigation and route planning for the aircraft. The pilot enters the flight plan, and the box figures out where the airplane is and where it's going next.
Full Definition
A flight management system (FMS) manufactured by Universal Avionics, designated the UNS-1, that integrates navigation, flight planning, and performance data into a single panel-mounted unit. It accepts inputs from multiple navigation sources (GPS, VOR/DME, inertial reference, etc.) and computes a continuous best- , allowing the pilot to fly programmed , , and through the or .