Flight Director System Operations | Auto Flight Control Mode

Flight Control panel airbus image download
Airbus A320 Flight control panel

Flight Director Systems

The (EADI) Electronic Attitude and Direction Indicator and the (EHSI) ElectronicHorizontal Situation Indicator are the two major components of a (FDS) Flight Director System. A mode selector and a Flight Director Computer are used in conjunction with the EADI and EHSI. The FDS combines the electronic flight instrument output data and create an easily readable display of the aircraft's flight path. The system can automatically compute the appropriate flight control instructions to attain and maintain the desired path by comparing this information with the preprogrammed flight path.

The flight director system receives data from the following sources

• Attitude Gyro

• VOR/Localizer/Glide Slope Receiver

• Radar Altimeter

• Compass system

• Barometric Sensors.

The flight director computer uses these data to provide flight control command information that enables the aircraft to:

• Fly a selected heading

• Fly a predetermined pitch attitude

• Maintain altitude

• Intercept desired VOR track and maintain that track

• Fly an ILS Glide Slope/Localizer.

Flight Director Control Panel

The mode selector switch and control panel on the flight director control panel supply the input information utilised by the FDS. The aircraft's desired pitch angle for climb or descent is pre-set via the pitch command control. The computed attitude of the aircraft to maintain the pre-selected pitch angle is then displayed on the FDS command bars. Many modes are available to the pilot, including HDG (Heading), VOR/LOC (for localizer tracking), and the AUTO APP or G/S. (for automatic capture and tracking of ILS and glide path). 

Other Names

Flight Director Control Panel names may vary, but the functions are almost the same. Aircraft manufacturers choose different names to respect copyright and perent. Flight Guidance Controller, Mode Control Panel, are some other names. 

Image of Airbus A320 Flight control panel is given in Title for reference.

The ability to integrate navigation features into the attitude indicator is extremely beneficial. The flight director helps to this usefulness by instructing the pilot on how to manoeuvre the plane to follow a predetermined path. The flight director control panel's VOR function connects the computer to the omnirange receiver. If the desired course selected the flight director displays the necessary bank attitude to intercept and maintain it. Automatic allocations for wind drift and determination of the intercept angle are made.

The complexity and features of flight director systems vary. Many contain functions like altitude hold, altitude choose, pitch hold, and more. Flight director systems, on the other hand, are meant to help the most during the instrument approach phase of flight. The ILS localizer and glideslope signals are supplied to the computer via the receivers and displayed as command indications. Using the flight director system, the pilot may fly the plane along the best approach path to the runway.

During the manoeuvring and process turn phases of an approach, level flight can be maintained by using the altitude hold feature. When the glideslope is intercepted, altitude hold is automatically disengaged. The flight director's command signals are maintained in a centred or zero condition once incoming on the localizer. The command pitch indicator shows a downward signal when the glideslope is intercepted. Any deviation from the normal glideslope path results in a command indication of fly-up or fly-down. The only thing the pilot has to do is keep the aeroplane symbol in the command bar.

Also Read

Post a Comment