What is FD on Airbus A320? (Flight Director)

The Airbus A320 is a popular aircraft used by many airlines around the world. It is known for its advanced technology and safety features, one of which is the Flight Director (FD) system. The Flight Director is a guidance system that assists pilots in flying the aircraft. In this article, we will explore what the Flight Director is, how it works, and its significance in the operation of the Airbus A320.

Understanding the Flight Director System

The Flight Director system on the Airbus A320 provides the pilots with guidance and commands to help them navigate the aircraft. It uses information from various onboard systems, such as the Inertial Reference System (IRS), Flight Management System (FMS), and Autopilot, to calculate and display flight information. The Flight Director displays this information on the Primary Flight Display (PFD) and the Navigation Display (ND).

The Flight Director system primarily consists of two components: the FD Bars and the FD Command Bar. The FD Bars are visual indicators that appear on the PFD and provide pitch and roll guidance to the pilots. They are represented as two lines that intersect in the center of the display. The FD Command Bar, on the other hand, provides lateral and vertical guidance. It is displayed as a small cross or bar with an arrow.

By following the guidance provided by the Flight Director system, pilots can maintain the desired flight path, altitude, and speed. The Flight Director takes into account factors such as weather conditions, aircraft weight, and the selected flight mode to provide accurate and precise guidance. It helps pilots during various phases of flight, including takeoff, climb, cruise, descent, and landing.

The Functionality of the Flight Director System

The Flight Director system on the Airbus A320 has several key functions that contribute to the safe and efficient operation of the aircraft. Let’s take a closer look at some of these functions:

1. Command Guidance

The Flight Director system provides pilots with command guidance, indicating the desired pitch and roll angles to be followed. This guidance assists the pilots in maintaining the correct attitude and heading during different phases of flight. The FD Bars on the PFD display the pitch and roll commands, helping the pilots to align the aircraft correctly with the flight path.

For example, during takeoff, the Flight Director system provides commands to the pilots on how to maintain the correct pitch angle for climb and how to roll wings level once airborne. The pilots can then follow these commands to achieve the desired flight profile.

2. Navigation Guidance

The Flight Director system also offers pilots navigation guidance, helping them to follow the selected flight path accurately. The FD Command Bar on the PFD provides lateral and vertical guidance to the pilots, indicating the correct track and altitude for the aircraft.

During a flight, the Flight Director system considers the inputs from the FMS and other navigational aids to calculate the most efficient and direct route. It then provides the necessary guidance to the pilots, who can follow the FD Command Bar to stay on the intended flight path and reach the desired waypoints.

3. Flight Mode and Automation Integration

The Flight Director system is intricately connected with other aircraft systems, such as the Autopilot and the Flight Management System (FMS). It integrates with these systems to provide accurate and coordinated guidance to the pilots.

During autopilot engagement, the Flight Director system can couple with the autopilot to follow the FD commands automatically. This integration allows for precise flying and reduces the workload on the pilots. Additionally, the Flight Director system takes into account the selected flight mode and adjusts its guidance accordingly.

For instance, during a managed climb or descent, the Flight Director system will provide guidance based on the selected altitude and speed constraints. It will ensure that the aircraft follows the programmed profile accurately.

The Significance of the Flight Director System

The Flight Director system plays a crucial role in enhancing flight safety and efficiency on the Airbus A320. It provides pilots with precise and intuitive guidance, allowing them to fly the aircraft accurately. By following the commands and guidance provided by the Flight Director, pilots can maintain the desired trajectory, altitude, and speed throughout the flight.

The Flight Director system also helps pilots in monitoring the aircraft’s performance and deviations from the desired flight profile. In the event of any deviations, the system provides immediate visual cues, allowing the pilots to take corrective actions promptly. This helps in the early detection and correction of any potential flight path deviations.

Furthermore, the integration of the Flight Director system with other systems, such as the Autopilot and FMS, enhances the overall automation and efficiency of the aircraft. It reduces pilot workload, especially during critical phases of flight, and allows them to focus on other essential tasks such as communication, monitoring, and decision-making.

In conclusion, the Flight Director system on the Airbus A320 is a vital component that provides pilots with accurate guidance and commands to fly the aircraft. Its command and navigation guidance functions, along with its integration with other aircraft systems, contribute to the safe and efficient operation of the aircraft. With the Flight Director system, pilots can confidently navigate the skies, ensuring a smooth and enjoyable flight experience for passengers.


1. Airbus. “A320 Aircraft Family.” https://www.airbus.com/aircraft/commercial-aircraft/a320-family.html

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