Flight Management System

The Flight Management System (FMS) is an integrated avionics computer that automates navigation, performance optimization, and flight planning tasks. It is the central 'brain' of a modern aircraft's avionics suite.

Core FMS functions include:

• Navigation: Multi-sensor position computation (GPS, DME/DME, VOR/DME, IRS)
• Flight planning: Route entry, waypoint management, SID/STAR selection
• Performance: Optimum altitude, speed schedule, fuel predictions, cost index computation
• Guidance: Lateral (LNAV) and vertical (VNAV) autopilot commands
• Predictions: ETA, fuel at destination, top of descent, step climb points

Pilots interact with the FMS via the MCDU (Multifunction Control Display Unit) or touchscreen displays on newer aircraft.