Flight Management System
Overview
A Flight Management System (FMS) is a fundamental component of a modern aircraft's avionics. An FMS is a specialized computer system that automates a wide variety of in-flight tasks, reducing the workload on the flight crew to the bare minimum. It collates navigation and performance data to calculate the aircraft's optimal flight path, speed and altitude, and can control the aircraft's autopilot to follow this flight path.
History and Development
The development of the FMS began in the 1970s, with the aim of reducing pilot workload during flight. The first FMS was introduced by Collins Aerospace, then known as Collins Radio Company, in 1973. The system was initially designed for the Airbus A300, the world's first twin-engined widebody airliner. The FMS has since evolved and improved, with modern systems offering a wide range of features including flight planning, navigation, performance computations, and aircraft guidance.
Components
A typical FMS consists of three main components: the Flight Management Computer (FMC), the Control Display Unit (CDU), and the Data Acquisition Unit (DAU).
Flight Management Computer
The FMC is the brain of the FMS. It is a specialized computer that processes the data input by the pilots through the CDU, and from the DAU. The FMC performs complex calculations to provide the most efficient flight path and to predict the aircraft's performance throughout the flight.
Control Display Unit
The CDU is the interface between the pilots and the FMS. It consists of a screen and a keyboard, and allows the pilots to input data into the FMS, such as the flight plan, and to monitor the information provided by the FMC.
Data Acquisition Unit
The DAU collects data from various aircraft systems and sensors, such as the air data computer, the inertial reference system, and the GPS. The DAU then sends this data to the FMC for processing.
Functionality
The FMS provides a wide range of functionalities to assist the pilots during flight. These include flight planning, navigation, performance computations, and aircraft guidance.
Flight Planning
The FMS allows the pilots to input a flight plan, which includes the departure and destination airports, the route to be followed, and any waypoints along the route. The FMS then calculates the optimal flight path, taking into consideration factors such as wind speed and direction, aircraft weight, and fuel consumption.
The FMS provides the pilots with precise navigation information. It uses data from the aircraft's sensors and from external sources, such as GPS, to determine the aircraft's position and to guide it along the flight path.
Performance Computations
The FMS calculates the aircraft's performance throughout the flight. It takes into account factors such as aircraft weight, fuel consumption, and environmental conditions to predict the aircraft's speed, altitude, and fuel burn at each point along the flight path.
Aircraft Guidance
The FMS can control the aircraft's autopilot to follow the flight path calculated by the FMC. It can also control the auto-throttle to maintain the optimal speed.
Future Developments
The FMS is continually evolving, with new features and capabilities being added regularly. Future developments are likely to focus on improving the system's efficiency and reducing pilot workload even further. This could include more advanced flight planning and navigation features, improved integration with other aircraft systems, and even the ability to control more aspects of the aircraft's flight.