The Interface of Flight Control in Connection with Basic Autopilot
The autopilots consist of either a single axis, a two-axis, or a three-axis system. A single-channel autopilot system will control the airplane in the roll axis only using the ailerons this is known as the primary axis and at its most basic provides lateral stability.
A two-channel autopilot controls the airplane about the roll and pitch axes using ailerons and elevators. The pitch axis is known as the secondary axis a three-channel autopilot that is standard on modern airliners’ controls. The airplane in all three axes rolls pitch and yaw axis is known as the third or tertiary axis and is controlled by the rudder.
Many multi-engine airliners have multiple 3-axis autopilots to allow a measure of redundancy and to provide the ability to carry out an auto land each autopilot has its own three inner loops and will inevitably be powered from different generators. If the servo motors are hydraulic. They will be powered by different hydraulic systems. An operator shall not conduct single-pilot operations in IFR conditions unless the airplane is equipped with an autopilot with at least altitude hold and heading mode.
This means that the aircraft must have at least a two axis or two-channel autopilot. Each autopilot has its own three inner loops and will inevitably be powered by different generators. If the servo motors are hydraulic. They will be powered by different hydraulic
Systems.
Each autopilot has its own three inner loops and will inevitably be powered by different generators. If the servo motors are hydraulic. They will be powered by different hydraulic systems.
The autopilot is coupled with the flight controls directly here the autopilot is mainly responsible for keeping the aircraft stable. If there are any disturbances the autopilot will deflect the control surfaces as required to bring the aircraft back to its original attitude. The autopilot will take corrective action and bring the aircraft back to its original flight profile by sending information to different flight control computers. After the autopilot is engaged the pilot can then select a pitch and roll guidance function as required.
The Interface of Hydraulic System in connection with Basic Autopilot (FLY-BY-WIRE)
When the rudder is moved so the ELAC 1 checks the received digital signal before sending it off to the flight control surfaces. From ELAC, the left turn digital signal then yet again runs through a wire or electric cable to one of the hydraulic actuators.
Just like in the power generated control, when the autopilot system sends electrical signals to the actuators to move the control column, the hydraulic system will give the power to control the surface.
Fly-by-wire aircraft have a full-time water trim system that operates in autopilot and manual control.
On the glare shield is the mode control panel which allows selections for the autopilot flight director and auto throttle.
To engage the autopilot the engage button for the selected autopilot is pressed. If the interlocks are made the autopilot will engage and the light in the button will illuminate to signify engagement. There will also be an indication of the flight mode enunciator.
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Principle of Auto Flight System and its control/ indicating in Cockpit
MULTIPURPOSE CONTROL AND DISPLAY UNIT (MCDU)
The MCDU is the primary entry/ display interface between the pilot and Flight Management and Guidance Computer.
FLIGHT CONTROL UNIT (FCU)
A flight control unit FCU is installed on the glare shield the FCU front face includes an AFS control panel between two AFS control panels. The AFS control panel allows and displays the autopilot and auto thrust engagement and the selection of guidance modes and flight parameters.
ELECTRONIC FLIGHT INSTRUMENT SYSTEM (EFIS) DISPLAYS
For EFIS displays, two primary flight displays PFDs and two navigation displays are located on the main instrument panel flight parameters are displayed on the PFD while the flight plan and navigation data are displayed on the MCDS.
The flight mode annunciator FM a is the top part of the PFD as the main guidance instrument each PFD displays. The autopilot flight director and auto thrust engagement status on the FMA, the autopilot flight director and auto thrust modes on the FMA, the landing category. The flight director symbols the various speeds and reference parameters.
SIDE STICKS
When the autopilot is engaged a solenoid operator detent locks both side sticks in the neutral position the autopilot is disengaged, and the side sticks become free. When the red push button on any side stick is pressed or when a force above a certain threshold is applied on any side stick.
THRUST LEVERS
Thrust levers allow the auto thrust function to be disengaged. Note that the thrust levers never move automatically. On the two flight control panels located on the overhead panel, there is a push-button two respectively disengage FAQ 1 and 2.
AUTOPILOT ENGAGEMENT
- Two AP (Auto Pilot) pushbutton switches located on FCU
- Provide short term control
AUTOPILOT DISENGAGEMENT
- Sidestick push button
- By force
- AP pushbutton on FCU