Aircraft Flight Controls

Aerospace Technology I

Facilitator-Mr. Lee

Adapted from- Aerospace: The Journey of Flight

Objectives • Name and describe the three axes of an

airplane and the means of their control.

• Compare and contrast flaps and slats.

• Compare and contrast spoilers and air breaks.

Introduction • The fuselage of a conventional airplane is

the basic structure to which all the other parts are attached.

• The primary source of lift is the wing:

o Attached to the wing are its ailerons.

• The tail (empennage) consist of:

o Horizontal stabilizer with its attached elevators

o Vertical stabilizer (vertical fin) with its attached rudder

The Axes of an Airplane • There are three axes of an airplane:

o Longitudinal (roll) axis

o Lateral (pitch) axis

o Vertical (yaw) axis

Longitudinal (Roll) Axis • Longitudinal (roll) axis runs from the tip of

the nose to the tip of the tail of the plane:

o Roll is the motion about the longitudinal axis

o Controlled by the aileron

One goes up, the other down

Change in lift is due to a change in the wing camber

Lateral (Pitch) Axis • Lateral (pitch) axis runs from one wingtip to

the other wingtip:

o Pitch is the motion about the lateral axis

o Pitching movement is caused by the elevator

The elevator can be deflected up or down as the pilot moves the control column backward or forward.

Movement increases the wings’ angle of attack creating more lift and causing the airplane to climb

Vertical (Yaw) Axis • Vertical (yaw) axis passes vertically through

the meeting point of the longitudinal and lateral axes:

o Yaw is the motion about the vertical axis

o Controlled by the rudder

Pilot presses the rubber petals in most aircraft

Flight Controls • Wilbur and Orville Wright gave the aviation

field sustained, controlled and powered flight of a heavier than air vehicle.

Flaps • Flaps are attached to the trailing edge

of the wing:

o When flaps are lowered either partially or fully, two things happen: lift is increased and so is drag

o The flap increases the camber of the wing airfoil for that portion of the wing to which it is attached

Allows slower flight because the stall speed is decreased

Slats • Slats are protrusions from the leading edge

of a wing.

o They add to the induced lift of a wing

o Slats cause energy to be added at the front, while the flaps cause energy to be added at the back

Effects of Aircraft Flight Controls

Spoilers & Drag Devices • Spoilers work to destroy lift:

o Spoilers are located somewhere on the top of the wing

• Drag devices produce drag only:

o Normally located on the fuselage

o Can be on the trailing edge of the wing

o Can be drag chutes too

Review • Name and describe the three axes of an airplane

and the means of their control.

o Longitudinal (roll) axis- controlled by ailerons

o Lateral (pitch) axis- controlled by the elevator

o Vertical (yaw) axis- controlled by the ruder

• Compare and contrast flaps and slats.

o Flaps are attached to the trailing edge of the wing

o Slats are protrusions from the leading edge of a wing

o They both increase lift and allow for slower speeds

Review… • Compare and contrast spoilers and air

breaks.

o Spoilers work to destroy lift:

Located on top of the wing

o Drag devices produce drag only:

Normally located on the fuselage

Can be on the trailing edge of the wing

Can be drag chutes too

Learn Long Live Long