Theory of Flight

6.02 Flight Controls References:

FTGU pages 30-31

6.02 Flight Controls

• MTPs:

– Axes of an Airplane

– Movements

– Function of the Controls

– Flutter

– Balancing Controls

Review

• Label the airplane!

Review

• What kind of construction are these?

Review

• How would you describe these aircraft?

Review

• What do the following terms mean? – Wingspan

– Chord

– Planform

– Aspect Ratio

– Angle of Incidence

– Relative Airflow

– Angle of Attack

– Airfoil

– Camber

Axes of an Airplane

Movements

Movements

• Roll – movement around longitudinal axis

• Pitch – movement around lateral axis

• Yaw – movement around vertical/normal

axis

Function of the Controls

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

Function of the Controls

• Ailerons are controlled using the

control column

• Control column RIGHT = right wing down

• Control column LEFT = left wing down

Function of the Controls

The elevator controls movement about the lateral axis This movement is called pitch.

Function of the Controls

• Elevators are controlled using the control

column

• Control column FORWARD = nose down

• Control column BACK =nose up

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

Function of the Controls

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

Function of the Controls

• The rudder is controlled using the

rudder pedals

Right rudder pedal = yaw right

Left rudder pedal = yaw left

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!

Balancing Controls

• Balancing control surfaces to help pilots

move them

• Examples:

– Inset hinge balance

– Rudder horn

– Aileron hinge axes

Balancing Controls

Balancing Controls

• Addition of mass (usually made of lead)

to control surfaces to prevent flutter

• Example:

– Lead mass added to rudder horn of glider

Balancing Controls

• A control surface has balance about it’s

centre of gravity without airflow over it

• Improper weight distribution can cause

flutter

• Static balance must be checked when

control surface is repainted

Confirmation

• Draw and label the three aircraft axis.

• Which movement occurs around each axis?

• Which control surface is used for each movement?

F-35B Hovering