BY MBACHI, ROHITH, JULES

Control Surfaces

Control Surfaces: Moveable surfaces on an airplane’s wings and tail allow a pilot to manoeuvre an airplane and control its attitude or orientation. These surfaces are called control surfaces and they work on the same principle as lift on a wing. They create a difference in air pressure to produce a force on the airplane to make it travel in a desired direction.

Pitching Moment: Pitch refers to a force trying to either raise or lower the nose of the .

Rolling Moment: This is the twisting force trying to roll the aircraft.

Yawing Moment: Yaw can be described as the rotation or twisting about the vertical axis of an aircraft. Yaw changes the direction that the aircraft's nose is pointing, either left or right.

Ailerons: An aircraft achieves a turn by varying the component of the wing's lifting force. To achieve a tilt, the rear outer section of each wing is hinged. These surfaces are known as . Ailerons cause motion about the longitudinal axis. This turning moment is known as the rolling moment. Ailerons are mounted on the of each wing near the wingtips and move in opposite directions.

When the pilot moves the stick left, or turns the wheel counter-clockwise, the left goes up and the right aileron goes down. A raised aileron reduces lift on that wing and a lowered one increases lift, so moving the stick left causes the left wing to drop and the right wing to rise. This causes the aircraft to roll to the left and begin to turn to the left. Centring the stick returns the ailerons to a neutral position.

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BY MBACHI, ROHITH, JULES

Secondary Effects of the Aileron: The deflected surface of the aileron causes a change in the on that wing which results in a yawing moment. The moment is opposite to the desired direction of roll and needs to be corrected by the .

Elevators: The is a moveable part of the horizontal , hinged to the back of the fixed part of the horizontal tail. The elevators move up and down together. When the pilot pulls the stick backward, the elevators go up. Pushing the stick forward causes the elevators to go down. Raised elevators push down on the tail and cause the nose to pitch up. The elevators cause the aircraft to pitch, that is, a nose up or a nose down motion. It can make the wings fly at a higher , which generates more lift and more drag. Centring the stick returns the elevators to neutral and stops the change of pitch.

Secondary Effects of the Elevator: N/A

Rudder: The rudder causes a yawing moment (about the normal axis). The rudder is a control surface typically mounted on the trailing edge of the vertical stabiliser of the aircraft's tail. When the pilot pushes the left pedal, the rudder deflects left. In the same manner, pushing the right pedal causes the rudder to deflect right. When the rudder is deflected right, the tail of the aircraft is pushed out left and causes the nose to yaw (twisting) to the right. Centring the rudder pedals returns the rudder to a neutral position and stops the yaw (twisting). The rudder can also be used to balance uneven airflow or engine forces. It is also used to change the heading or to align the aircraft with the airflow.

Secondary Effects of the Rudder: If rudder is continuously applied in level the aircraft will yaw initially in the direction of the applied rudder. After a few seconds the aircraft will tend to bank in the direction of yaw. This arises initially from the increased speed of the wing opposite to the direction of yaw and the reduced speed of the other wing. The faster wing generates more lift and so rises, while the other (slower) wing tends to go down because of less lift being generated.

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BY MBACHI, ROHITH, JULES

Text Bibliography ➢ anonymous. 2017. Control Surfaces | How Things Fly. [ONLINE] Available at:http://howthingsfly.si.edu/flight-dynamics/control-surfaces. [Accessed 13 May 2017]. ➢ Flight control surfaces - Wikipedia. 2017. Flight control surfaces - Wikipedia. [ONLINE] Available at:https://en.wikipedia.org/wiki/Flight_control_surfaces. [Accessed 13 May 2017]. ➢ - Wikipedia. 2017. Empennage - Wikipedia. [ONLINE] Available at:https://en.wikipedia.org/wiki/Empennage. [Accessed 13 May 2017]. ➢ - Wikipedia. 2017. Vertical stabilizer - Wikipedia. [ONLINE] Available at:https://en.wikipedia.org/wiki/Vertical_stabilizer. [Accessed 13 May 2017]. ➢ - Wikipedia. 2017. Tailplane - Wikipedia. [ONLINE] Available at:https://en.wikipedia.org/wiki/Horizontal_stabilizer. [Accessed 13 May 2017].

Media Bibliography ➢ File:Alieron A-44 (PSF).png - Wikipedia. 2017. File:Alieron A-44 (PSF).png - Wikipedia. [ONLINE] Available at: https://en.wikipedia.org/wiki/File:Alieron_A-44_(PSF).png. [Accessed 13 May 2017]. ➢ http://www.dutchops.com/Portfolio_Marcel/Articles/Aerodynamics/Forces/Images/F orces.jpg ➢ www.youtube.com. 2017. No page title. [ONLINE] Available at: https://www.youtube.com/watch?v=A2BcAMl04AI. [Accessed 13 May 2017]. ➢ YouTube. 2017. Effects of Aircraft Controls - YouTube. [ONLINE] Available at: https://www.youtube.com/watch?v=TSS3TjEsGkw. [Accessed 13 May 2017]. ➢ http://www.allstar.fiu.edu/aero/images/L1-Pic4-2.gif ➢ https://3.bp.blogspot.com/_HWNuU41CrJE/S9dTGUNszBI/AAAAAAAAAC8/vmF MOYrWfpA/s1600/Roll_Pitch_Yaw.jpg ➢ http://www.rc-airplane-world.com/image-files/xrc-airplane- ailerons.gif.pagespeed.ic.YNszB3be2n.png ➢ http://2.bp.blogspot.com/_2WhIc3hA9G0/TCoNaw1emNI/AAAAAAAAALs/a5k5V m7H-Vs/s640/airplane-elevators.gif ➢ http://www.rc-airplane-world.com/image-files/rc-airplane-controls-rudder.gif

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