Theory of Flight

1
Theory of Flight

• 6.02 Flight Controls
• References
• FTGU pages 30-31

2
6.02 Flight Controls

• MTPs
• Axes of an Airplane
• Movements
• Function of the Controls
• Flutter
• Balancing Controls

3
Review

• Label the airplane!

4
Review

• What kind of construction are these?

5
Review

• How would you describe these aircraft?

6
Review

• What do the following terms mean?
• Wingspan
• Chord
• Planform
• Aspect Ratio
• Angle of Incidence
• Relative Airflow
• Angle of Attack
• Airfoil
• Camber

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Axes of an Airplane
8
Movements
9
Movements

• Roll movement around longitudinal axis
• Pitch movement around lateral axis
• Yaw movement around vertical/normal axis

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Function of the Controls
Ailerons cause movement around the longitudinal
axis This movement is called roll.
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Function of the Controls

• Ailerons are controlled using the control column
• Control column RIGHT right wing down
• Control column LEFT left wing down

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Function of the Controls
The elevator controls movement about the lateral
axis This movement is called pitch.
13
Function of the Controls

• Elevators are controlled using the control column
• Control column FORWARD nose down
• Control column BACK nose up

14
Function of the Controls

• An alternative to the elevator is the stabilator
• It is controlled the same way the elevator is
• The entire horizontal stabilizer moves to act as
  an elevator

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Function of the Controls
The rudder controls movement around the vertical
axis. This movement is called yaw.
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Function of the Controls

• The rudder is controlled using the
• rudder pedals
• Right rudder pedal yaw right
• Left rudder pedal yaw left

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Flutter

• What is flutter?
• Rolling or weaving motion arising from deflection
  of a part of the airplane structure that causes
  the air forces on it to change in synchronism
  with its natural period of vibration
• Control surfaces must be balanced properly to
  prevent flutter!

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Balancing Controls

• Balancing control surfaces to help pilots move
  them
• Examples
• Inset hinge balance
• Rudder horn
• Aileron hinge axes

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Balancing Controls
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Balancing Controls

• Addition of mass (usually made of lead) to
  control surfaces to prevent flutter
• Example
• Lead mass added to rudder horn of glider

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Balancing Controls

• A control surface has balance about its centre
  of gravity without airflow over it
• Improper weight distribution can cause flutter
• Static balance must be checked when control
  surface is repainted

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Confirmation

• Draw and label the three aircraft axis.
• Which movement occurs around each axis?
• Which control surface is used for each movement?

23
F-35B Hovering