1. Leading Cadet Training
Principles of Flight
Leading Cadet Training
Control
Lecture 5

2. Pilot Controls A pilot has 3 main controls
to move the aircraft about its 3 axes.
Ailerons, Elevators and a Rudder
Using these controls the pilot can:
Pitch – make the nose rise or fall
Roll – make one wing rise and the other fall
Yaw – make the nose move left or right
Elevators
Rudder
Ailerons

3. The Pitching Plane Elevators make the aircraft nose rise or fall.
They are hinged to the trailing edge of the tailplane,
and linked to the pilots control column – ‘The Stick’

4. The Pitching Plane Moving the stick forwards lowers the elevators,
and gives an angle of attack which creates lift,
and the aircraft is tail-up, nose–down,
about its lateral axis.
Lateral Axis
Lift
Angle of Attack α
Control Column
Pushed Forward

5. The Pitching Plane Moving the stick backwards raises the elevators,
creating the opposite effect,
and the aircraft is tail-down, nose–up,
about its lateral axis.
Lateral Axis α
Angle of Attack
Lift
Control Column
Pulled Backward

6. The Rolling Plane
Ailerons make the aircraft roll about its longitudinal axis.
They are hinged to the trailing edge of each wing.
and linked to the pilots control column – ‘The Stick’

7. The Rolling Plane Moving the stick to the left raises the LEFT aileron
and depresses the RIGHT aileron.
The left aileron has a reduced angle of attack
and reduced lift
The right aileron has an increased angle of attack
and increased lift
The aircraft rolls to the left about its longitudinal axis.
Lift
Lift
Control Column
Pushed LEFT

8. The Rolling Plane
Moving the stick to the right raises the RIGHT aileron
and depresses the LEFT aileron,
creating the opposite effect,
and the aircraft rolls to the right
about its longitudinal axis.
Lift
Lift
Control Column
Pushed RIGHT

9. The Yawing Plane
The Rudder makes the aircraft nose move left or right.
It is hinged to the trailing edge of the fin,
and linked to the rudder pedals in the cockpit.

10. The Yawing Plane Moving the LEFT pedal forwards
moves the rudder to the left,
this produces a sideways force to the right.
The tail is pushed to the right
and the nose moves to the left.
New
Flight Path
Force
Original
Flight Path
Rudder Pedals
LEFT Forwards

11. The Yawing Plane Moving the RIGHT pedal forwards
moves the rudder to the right,
creating the opposite effect,
The tail is pushed to the left
and the nose moves to the right.
Original
Flight Path
Force
New
Flight Path
Rudder Pedals
RIGHT Forwards

12. Trimming Tabs, Flaps & Slats
The weight and position of an aircrafts
Centre of Gravity can change when:
Fuel is used, Bombs dropped, Ammunition fired, etc.
The Centre of Pressure will also change due to:
Change in Power, Speed and Attitude
All these changes will affect the balance of forces
on the aircraft
There are a number mechanisms that assist pilots
in these cases.

13. Trimming Tabs Stick Force Removed Stick Force Remains
Help comes in the form of ‘trimming tabs’,
which are hinged to the trailing edges
of the elevators, ailerons and rudder.
Aileron Trim Tab
Elevator Trim Tabs
Rudder Trim Tab
Larger
Moment Arm +
Pull Force
+ + +
+ +
Stick Force Remains
Stick Force Removed

14. Flaps An aircraft’s wing is designed
so that the aircraft can make its approach
at a controlled slow speed,
along a moderately steep approach path.
A well-proven solution is to add flaps
for use on the approach and landing.

15. Flaps Flaps are hinged surfaces
usually fitted to the trailing edge of wings
before the ailerons to increase lift.
Plain Flap
(or Camber)
Flaps
50% Increase CLMAX Critical Angle 12o
Split Flap
60% Increase CLMAX Critical Angle 14o
Slotted Flap
65% Increase CLMAX Critical Angle 16o
Blown Flap
80% Increase CLMAX Critical Angle 16o
Fowler Flap
90% Increase CLMAX Critical Angle 15o

16. Flaps Flaps 60o Flaps 90o Flaps 30o Drag Effects on Flaps Flap Lift
Large Inc
Small Inc
No Sig Inc
Drag
Small Inc
Large Inc
V Large Inc

17. Slats Slats improve handling at low speeds.
They are small aerofoils positioned along the
leading edge of each wing.
Open
Slat
Slats
40% Increase CLMAX Critical Angle 20o
Fixed
Slat
50% Increase CLMAX Critical Angle 20o
Droop Snoot
Slat
50% Increase CLMAX Critical Angle 20o
Kruger
Slat
50% Increase LLMAX Critical Angle 25o
Automatic
Slat
70% Increase CLMAX Critical Angle 25o

18. Slats If the wing reaches a high angle of attack, the slat opens.
Air can now flow between the slat and the wing.
The shape of the slot accelerates air through it
improving the pattern of airflow over it.
Direction of airflow
Slat
Direction of airflow

19. Lift Augmentation α Effects on CL CL CL BASIC AEROFOIL SECTION
(the ratio between
lift and dynamic pressure).
Effects on CL CL
BASIC AEROFOIL SECTION
TRAILING EDGE FLAP
LEADING EDGE FLAP
SLAT OR SLOT α

20. Check of Understanding
In position 1 the aircraft is climbing vertically.
To make the aircraft move to position 2 and then 3,
Which way must the pilot move the control column?
To the right
To the left
Backward
Forward

21. Check of Understanding
What control would a pilot use
to make an aircraft roll?
Aileron
Fin
Rudder
Elevator

22. Check of Understanding
On the diagram, what does the arrow point at?
The elevator trimming tab
The rudder trimming tab
The fin
The aileron

23. Check of Understanding
What will happen if flaps are lowered
during the approach to land?
Drag will be decreased
Lift will be increased
A higher touch-down speed is needed
The stalling speed will be increased

24. Check of Understanding
Which of these diagrams represents a Fowler Flap? W X Y Z

25. Check of Understanding
On this cross-section of a wing,
which letter points to a slat? U T S R

26. Leading Cadet Training
Principles of Flight
Leading Cadet Training
End of Presentation