Definition
An integrated airborne computer system that automates a wide range of in-flight tasks, including navigation, performance calculations, and flight planning. A Flight Management System (FMS) uses a navigation database combined with inputs from sensors such as GPS, inertial reference units, and radio navigation aids to compute and follow a programmed flight route, manage vertical and lateral guidance, and provide steering commands to the autopilot or flight director.
Plain English
The aircraft's main onboard computer for flight planning and navigation. The pilot enters the route and altitudes, and the system works out where to fly, how to get there, and feeds that information to the autopilot.
Context Anchor
Pilots encounter Flight Management Systems when entering a route before flight, checking navigation during flight, or using cockpit guidance for instrument procedures.
Derivation
The name describes the function: a system that manages the flight. 'Manage' comes from the Latin manus, meaning 'hand' — originally suggesting handling or directing something. Here, the system handles the routine workload of navigation and performance so the crew can focus on monitoring and decision-making.
Why Pilots Care
Reduces pilot workload during complex flights and improves accuracy and fuel efficiency.
Analogy
A Flight Management System is somewhat like a car navigation system combined with a trip calculator, but built for aircraft and tied into cockpit instruments and aircraft data.
Intuition Check
Flight Management Systems do not replace the pilot. They organize and provide guidance information; the pilot still checks the route, confirms the entries, and makes sure the aircraft is doing the correct thing.
Example Sentence 1
Before pushback, the crew programmed the departure, route, and arrival into the Flight Management System.
Example Sentence 2
During the flight, the Flight Management Systems automatically adjusted the aircraft's speed to meet the arrival time.