Small aircraft control surfaces


Anyone who has held their hand out of a car into the wind to play airplane already has a fundamental impression of control surfaces on the airplane. When the heel of the palm went down, the airpressure under the hand pushed the hand up. That's called lift. The airflow over/under the hand changes with the shape of the hand or airfoil. If you had little cut-outs near your wrist, there wouldn't be as much lift. The tail section contains control surfaces for keeping the plane stable and controllable. 1) Horizontal: The horizontal, non-moving part is called the stabilizer, and it prevents uncontrolled up-and-down motion of the nose. The small hinged sections on each side are called elevators, which work in unison. It is controlled by the cockpit control wheel/stick and increases or decreases lift. When forward pressure is applied on the wheel, the elevators move downward, which increases the length of the tail causing more lift, which forces the tail upward, causing the nose to drop. There is also a small hinged section in the elevator which is controlled by a small vertical wheel on the cockpit console which is used to finetune the elebator trim. Hense the name trim tab. 2) Vertical: The vertical non-moving part which prevents the nose from uncontrolled swinging side to side. The large hinged section is the rudder. The rudder is controlled by the foot pedals in the cockpit, and deflects the tail to the right or left. The wings generate most of the lift to hold the plane in the air. Different models of aircraft will have wings of different shapes and in different vertical locations. On a Cessna, the wing is high, and on a Piper, it is low. On an F14, the can change from a forward angle to "swept back". On most small planes, the wings also carry the fuel. There are many control surfaces on a wing: 1) The aileron is the hinged part of the back of the wing towards the tip which is used to roll the wings from side to side. There is one on each side of the plane and they work opposite of each other. When one moves up, the other moves down. 2) Flaps are the hinged sections on the back of the wing near the fuselage. Flaps are deployed downward on takeoff and landing to increase the lift produced by the wing and allows the plane to fly at slower speeds. 3) Spoilers and Slats are used on high performance/commercial aircraft and also changed the aerodynamics of the wing.