To drive (fly) the aircraft to the desired location we need control surfaces and also to recover the aircraft from disturbed position to stable position we need stabilizers and control surfaces,
The primary control surfaces of the aircraft are:
AILERON: FOR ROLLING
Ailerons are placed near the edge of the wings (the longitudinal stabilizer). Both ailerons have counter motions to say if the right aileron goes up then the left one will go down and vice versa in that way they connected to the control mechanisms.
Ailerons are activated by moving the cockpit control column to left and right
To make the aircraft roll right a pilot need to move the control column to the right this will make the left aileron to go down and the right to go up so the lift in the left wing will increase and the right will decrease, It will make the left wing to go up and the right go down so the aircraft roll right, similarly for the left roll control column will be moved left and left aileron go up, right go down thus increasing the lift in right wing and reduced lift in left wing so the aircraft will roll left.
Ailerons used to acheive lateral stability and roll the aircraft based on longitudinal axis.
In aircraft this rolling movement used to turn the aircraft left and right , it is called Banking .With out using the rudder we can turn the aircraft left and right, Slightly rolling the aircraft to the right will make the lift component to be in the upward right direction so the aircraft turn right and the same principle to the left. This is called Bank left or right.
ELEVATOR : FOR PITCHING
Elevator placed in horizontal stabilizers, it is used for pitch up and pitch down movements of the aircraft.
Elevator activated by moving the control column front and back.
To pitch the aircraft up the pilot needs to move the control column backward this make the elevator go up . This up positioned elevator induces downward force in the back of the aircraft so the nose portion of the aircraft will go up thus pitch up movement achieved. Similarly by moving the control surface to the front the elevator will be place downward this induces a upward movement in the back of the aircraft so the tail goes up and the nose go down.
Elevator used to achieve Longitudinal stability and pitch the aircraft based on Lateral axis.
RUDDER: FOR YAW
Rudder placed in vertical stabilizers. It is used to yaw the aircraft left and right.
Elevator activated by pushing the pedals by the legs.
To yaw the aircraft right we need to push the right side pedal this will make the rudder to deflect right side, it induces the force that tends to move the tail to the left so the nose move right. Similarly by pushing the left rudder the elevator will be deflected left and the tail move right so the nose move left.
Rudder yaw the aircraft based on vertical axis.
Elevons means Elevator + Aileron. In some aircraft one structure is do the work of both ailerons and elevator (example in delta wing aircraft). That surface is known as elevons.