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3 axis of flight

an aircraft will rotate around the centre of gravity, which is at the aircraft’s centre of mass. each axis (longitudinal, lateral, and normal / vertical) are perpendicular to each other. there are 3 fundamental axis of flight - roll (rotational about longitude), pitch (rotation about lateral), and yaw (rotation about normal).

ROLL

roll is rotation about the longitudinal (horizontal) axis to bank the plane left or right. it’s controlled by turning control column left or right, which then lifts or lowers each aileron on the wings in opposition. by lifting one and dropping the other, there is more lift on the raised aileron, so the plane will bank to the side of that of the dropped aileron. rolling is an act of centripetal motion, as the centripetal force of the aircraft acts towards the centre of a circular path.

to roll left -

  1. the control column is pushed to the left

  2. the right aileron lifts and the left aileron drops, so there is more lift on the right wing

  3. this means the aircraft banks left, rolling around the horizontal axis to turn left

to roll right -

  1. the control column is pushed to the right

  2. the left aileron lifts and the right aileron drops, so there is more lift on the left wing

  3. this means the aircraft banks right, rolling around the horizontal axis to turn right

PITCH

pitch is rotation about the latitude (horizontal) axis to pitch the plane up or down. it’s controlled by turning control column up (to pitch up) and down (to pitch down), which then lifts or lowers the elevators on the horizontal stabilisers. the elevators move together, unlike the ailerons which move in opposite directions to each other. elevators work by varying the amount of lift created at the tailplane, dictating whether the tailplane is higher or lower than the nose, and therefore whether the aircraft goes up or down.

to pitch up -

  1. the control column is pulled towards the pilot

  2. the elevator rises, so there is less lift at the tailplane. the tailplane drops to be lower than the nose

  3. therefore the plane is at an upwards trajectory and will move upwards

to pitch down -

  1. the control column is pushed away from the pilot

  2. the elevator lowers, so there is more lift at the tailplane. the tailplane rises to be above the nose

  3. therefore the plane is at a downwards trajectory and will move downwards

YAW

yaw is rotation about the normal (vertical) axis to turn the plane left or right. it’s different to ‘roll’ in the sense that the plane does not need to bank to turn, and because yaw is not an example of centripetal motion. it’s controlled using rudder pedals to rotate the aircraft left or right, which will move the rudder, located on the vertical stabiliser, in the same way, creating horizontal lift at the other side of the rudder which then rotates the tailplane in the given direction.

to yaw left -

  1. the left rudder pedal is pushed

  2. the rudder will come over to the left, which creates horizontal lift on the rudder’s left side

  3. this rotates the plane around the vertical axis, turning to the plane to face the left

to yaw right -

  1. the right rudder pedal is pushed

  2. the rudder will come over to the right, which creates horizontal lift on the rudder’s right side

  3. this rotates the plane around the vertical axis, turning to the plane to face the right