Flight controls

1.

FLIGHT CONTROLS
MENU
System presentation
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2.

We will begin
this module by
explaining
the
basic concept of
the “Fly By Wire“
system.
FLIGHT CONTROLS
MENU
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3.

This
has
the
advantage of saving
weight
on
the
aircraft,
However,
there
are, even greater
advantages as the
video
clip
will
demonstrate.
In conventional
aircraft,
the
movement of the
control column is
transferred
along
cables and pulleys,
until it reaches the
control surface to
be moved.
In
the
A320
family however, the
cables and pulleys
have been replaced
by electrical wires.
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MENU
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4.

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5.

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MENU
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6.

FLIGHT CONTROL
COMPUTERS
The electrical signals created by sidestick
movement travel through flight control computers
before being passed to the surface hydraulic
actuators, also named servo controls.
These computers analyze the signal to check that
it is a safe command and ensure the optimum flight
control surface deflection for the demand.
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MENU
System presentation
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7.

FLIGHT CONTROL
COMPUTERS
This has advantages over conventional
systems. It :
• makes the aircraft extremely stable,
• enhances safety,
• reduces the workload of the pilot.
Let’s now look at the flight control
surfaces themselves.
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MENU
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8.

L
AIL
R
AIL
FLIGHT CONTROLS
MENU
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9.

R
AIL
L
AIL
L
ELEV
R
ELEV
FLIGHT CONTROLS
MENU
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10.

R
AIL
L
AIL
PITCH TRIM
L
ELEV
R
ELEV
FLIGHT CONTROLS
MENU
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11.

R
AIL
L
AIL
PITCH TRIM
L
ELEV
RUD
R
ELEV
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MENU
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12.

SPD BRK
L
AIL
R
AIL
PITCH TRIM
L
ELEV
RUD
R
ELEV
The flight control system incorporates:
Ailerons,
Elevators,
A Trimmable Horizontal Stabilizer (THS) for pitch trim,
A rudder,
Ground spoilers/Speed brakes.
FLIGHT CONTROLS
MENU
System presentation
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13.

SPD BRK
L
AIL
R
AIL
PITCH TRIM
L
ELEV
RUD
R
ELEV
Now let’s introduce the ECAM F/CTL page.
You can see that all the flight control surfaces
we have talked about are displayed. We will now
see them in more detail.
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MENU
System presentation
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14.

The movements of both ailerons and both
elevators are symbolized by a green index moving
in front of a white scale.
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MENU
System presentation
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15.

The green rudder symbol is used as an index to display
the movements of the rudder on a white scale.
The rudder trim is indicated by a small blue line below
the scale.
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MENU
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16.

Note that the rudder and the pedal
deflections are limited as a function of speed
via a rudder travel limiter.
High speed position
The high speed position is indicated by
small white ticks on the rudder scale.
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MENU
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17.

The PITCH TRIM position is indicated by THS
deflection in degrees up or down.
Let’s continue with the spoilers.
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MENU
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18.

The
spoilers
functions:
have
several
• Speed brakes use the 3 central
surfaces,
FLIGHT CONTROLS
MENU
System presentation
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19.

• Roll control uses the four outer
surfaces,
On the video, look at the left spoilers
as they deploy, then at the right ones as
the wings are leveled .
Click on the video window to start it !
FLIGHT CONTROLS
MENU
System presentation
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20.

• Ground spoilers use all surfaces.
On the video, watch as all the spoilers deploy
at touchdown.
Click on the video window to start it !
FLIGHT CONTROLS
MENU
System presentation
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21.

On the ECAM F/CTL page, the spoiler extended position
is indicated by small arrows. This is the speed brake case.
All these control surface indications will be explained in
more detail in the normal and abnormal operation modules.
Now, we will look at the flight control computers.
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MENU
System presentation
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22.

Flight control computers
SEC 1
ELAC 1
FAC 1
SEC 2
ELAC 2
FAC 2
SEC 3
The movements of the flight control surfaces are managed by seven computers. These are:
Two ELevator and Aileron Computers (ELAC),
Three Spoiler and Elevator Computers (SEC),
Two Flight Augmentation Computers (FAC).
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MENU
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23.

ELAC 1
ELAC 2
FCDC 1
FCDC 2
SEC 1
In addition, two Flight Control Data
Concentrator computers (FCDC) are
used to acquire data from the ELAC and
SEC. Then, they send it to the EIS.
SEC 2
SEC 3
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MENU
System presentation
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24.

ELAC 1
However, the data from both FAC is
sent directly to the EIS.
ELAC 2
FCDC 1
FCDC 2
SEC 1
SEC 2
FAC 1
SEC 3
FLIGHT CONTROLS
FAC 2
MENU
System presentation
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25.

ELAC 1
ELAC 2
SEC 1
SEC 2
SEC 3
The status of ELAC and SEC is indicated on the ECAM
F/CTL page. The other computers are not displayed.
These indications will be seen in more detail in the
abnormal operation module.
Now, we will see the hydraulic aspect.
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MENU
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26.

Three independent hydraulic systems are used to power all the flight control surfaces.
FLIGHT CONTROLS
MENU
System presentation
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27.

The hydraulic systems which actuate each
control surface are indicated on the ECAM F/CTL
page by the use of G, B and Y.
For example, the rudder is powered by the
Green, Blue and Yellow hydraulic systems.
The ECAM F/CTL page is now complete.
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MENU
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28.

Pilots control pitch and roll through two side
sticks.
FLIGHT CONTROLS
MENU
System presentation
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29.

There are associated side stick
priority lights.
Side sticks and priority lights will
be explained in a separate module.
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MENU
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30.

Pitch trim wheels are located on
the center pedestal.
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MENU
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31.

There are two sets
conventional rudder pedals.
FLIGHT CONTROLS
MENU
System presentation
of
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32.

A RUD TRIM panel is located on
the pedestal.
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MENU
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33.

A speed brake lever is located on
the left side of the pedestal.
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MENU
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34.

In addition, there are two panels, located
on the overhead panel to control the flight
control computers .
Now,
we
will
introduce
augmentation devices.
FLIGHT CONTROLS
MENU
the
lift
System presentation
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35.

There are 5 slats on each
leading edge ...
FLIGHT CONTROLS
MENU
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36.

and 2 flaps on each trailing
edge.
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MENU
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37.

SFCC 1
SFCC 2
The slats and flaps are hydraulically actuated like
all the other surfaces. They are electrically controlled
via two Slat Flap Control Computers (SFCC).
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MENU
System presentation
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38.

SFCC 1
SLAT CHANNEL
FLAP CHANNEL
SFCC 2
SLAT CHANNEL
FLAP CHANNEL
Each SFCC has two channels, one for the flaps
and one for the slats.
Each channel can drive its associated surfaces.
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MENU
System presentation
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39.

The flap lever, located on the right
side of the pedestal, operates the slats
and flaps.
The flap lever has the following
positions:
0, 1, 2, 3 and FULL.
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MENU
System presentation
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40.

The flaps and slats information is shown on the E/WD.
The flap and slat positions are indicated by white dots.
Here, the surfaces are extended to position 1+F.
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MENU
System presentation
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41.

This is Flap 0 indication. Notice there is no labeling with
this setting.
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MENU
System presentation
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42.

The slats and flaps are fitted with
protection functions.
In particular, Surface asymmetry
between left and right wing, Surface
attachment
failure,
Overspeed
or
uncommanded movement are detected.
All these protections will be seen in
detail in the abnormal operation
modules.
Module completed
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MENU
System presentation
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NEXT

43.

LIST OF SUBJECTS
FLIGHT BY WIRE
FLIGHT CONTROL SURFACES
ECAM PAGES
COMPUTERS
HYDRAULIC
CONTROLS
SLATS and FLAPS
AUDIO
GLOSSARY
RETURN
FLIGHT CONTROLS
FCOM
EXIT
MENU
System presentation
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