Flight Management Systems

The Flight Management System (FMS) is the heart of navigation, enabling flight preparation, calculating and delivering flyable trajectories to the crew, setting flight parameters and ensuring aircraft guidance as the flight plan progresses.

The FMS was developed to relieve pilots of navigational tasks and to help them manage the aircraft’s optimum trajectory, in accordance with international regulations. Developed in the 1960s, the first FMS were installed on board Airbus 310 and Boeing 757 commercial aircraft in the 1980s. 

At Thales, the first FMS was developed for the A320 and was known as FMS300. Other systems have been developed for the regional and helicopter markets. These systems, known as FMS200, are well known on aircraft such as the ATR-600 or the UH60V Black Hawk helicopter.

7,000+ aircraft have been equipped with Thales FMS, cumulating over 100 million flight hours.

FMS200 users benefit from Thales’s 40 years of FMS expertise. Thales now supplies equipment for more than 500 aircraft per year. Pilots around the world trust our FMS products  for a full-featured FMS that provides accurate navigation calculations and and precise trajectory control.

Thales FMS users benefit from a dramatic reduction in pilot workload and time spent on FMS operations. The intuitive interface makes it easy to perform basic tasks such as creating new waypoints along the route which may include unique descent altitude constraints. More complex tasks such as creating a custom 3-dimensional arrival to any airport or location are equally easy.

• What you see is what you fly: Navigation Display interface including scrolling mode and trajectory display.

• Temporary and multiple secondary Flight Plans for “what-if” scenarios.

• Undo function to discard flight plan modifications.

• Reduced pilot workload during all phases of flight (take-off, climb, cruise, descent and approach) is realized when the FMS is fully coupled (LNAV & VNAV) to the autopilot

The FMS interface is designed to be easy to use and intuitive, with easy and fast initialization. A limited number of pages allows quick access to all information and inputs. This reduces training time and allows the pilot to quickly become familiar with the capabilities of the FMS.

Aircraft in flight need to cooperate closely with air traffic surveillance and control systems. Each flight involves surface manouvers, take-off, climb, cruise, descent and approach, landing and then taxiing phases at the destination airport.

All these operations are increasingly automated and, under the control of the pilot who retains ultimate authority, conducted by a flight management system. The mission management, guidance and positioning tasks performed by the FMS are an essential aid to flying the aircraft.

The FMS ingests all data from the aircraft’s avionics system, as well as data input directly by the pilot or communicated to the aircraft by the airline, in particular flight plan data, navigation data (VOR, ILS, DME, etc.), external data (temperature, pressure, etc.) and aircraft characteristics (weight, centre of gravity, etc.). The FMS then sends commands to the autopilot and information for display to the crew.

Commercial airliners fly most of the time under IFR (Instrument Flight Rules). All aircraft flying in this navigation mode must register a flight plan before departing. The flight plan contains a set of information supplied to air traffic authorities about the flight, the type of aircraft and its equipment, and the number of passengers on board.

Based on this flight plan, the authorities can provide information and control services to the aircraft, as well as alerting services if necessary. If changes are made to the flight plan on the ground or in flight, the aircraft must inform the air traffic control services with which it is in contact or local services in the flight region.

A key function of the FMS is to help the pilot prepare the flight plan. For this it relies on its navigation database (NDB) in ARINC 424 standard format, loaded and updated regularly into its memory via a data loader.

The NDB contains all the information needed to prepare a flight plan: waypoints, airways, ground navigation aids (DME, VOR, etc.), airports, runways, standard instrument departures (SID), standard terminal arrival routes (STAR) and holding patterns.

The NDB can also contain a list of preset flight plans. The flight plan of course depends on the type of aircraft, but it is always prepared through the FMS using similar procedures. Particular parameters such as the cruise altitude and quantity of fuel on board can then be entered in the FMS.

This operation can be fully automated if the pilot selects a standard airline flight plan already in the FMS memory. But most airlines employ professional flight dispatchers to do this job and send the flight plan directly to the aircraft’s FMS via an ACARS, wireline or wireless datalink from the airline dispatch centre. The pilot can of course modify the flight plan once in flight and then communicate changes to airlines and air traffic authorities over a range of available datalinks

The FMS incorporates a model of the aircraft (indicating weight distribution, propulsion system, aerodynamic characteristics and so forth), allowing it to precisely calculate lateral and vertical trajectory to follow the flight plan. Management of vertical trajectory is particularly important from a cost viewpoint. As the aircraft burns fuel it gets lighter, so the FMS constantly makes adjustments to achieve the most economical speed and altitude (ECON mode). The FMS can also receive weather updates via datalink to modify the flight plan and optimise flying conditions accordingly.

Another important factor calculated by the FMS is the top of descent point (TOD), which depends on the required time of arrival (RTA), flight plan (constraints during the arrival procedure), winds and aircraft model. From the TOD, the FMS determines a 4D trajectory – in the three spatial dimensions plus time – and generates commands to adhere to. The ideal trajectory is one that minimises fuel consumption, pollution and noise.

To establish, manage and optimise the flight plan in terms of flight time and fuel consumption, the FMS relies on two databases: the navigation database (NDB) and the aircraft performance database. To generate the onboard database, Thales adapts this format using tools developed in strict compliance with a process called RTCA DO-200/EUROCAE ED-60, which guarantees the origin and integrity of data loaded into the database. The NDB must be regularly updated to stay compatible with changes to infrastructures and air operations. All NDBs are updated across an airline fleet according to a 28-day AIRAC (Aeronautical Information Regulation and Control) cycle defined by the ICAO.

For Navigation Database from major providers or aircraft performance database from OEMs, Thales masters the process to generate such kind of data.

The Pureflyt FMS is the most innovative and powerful Flight Management System built by Thales, soonly available on the market (2026). It was selected by Airbus in 2022 and will be adapted to fit with Airbus specificities onboard the A320 and A330.

This next generation flight management systems (FMS) will bring at the entry-into-service new features for greener and more economical flights like Continuous Descent Approach, Flight Criteria management, more tools for what-if scenarios and a cyber-secured bi-way connectivity to the open world.

Furthermore this state-of-the-art hardware has been designed and specified to support the whole functional roadmap for the coming decades. This new platform available in linefit and retrofit on the existing and future aircraft will ensure functional and operational continuity.