surfaces that normally lie flush with the wing but can be raised. A similar surface called an air brake, extends at right angles to the under-surface of the wing to slow the speed of the plane.AileronsAilerons control rolling movement around the longitudinal axis. Ailerons are usually placed far out on the wing. Leftward movement of the stick or the wheel raises the left aileron and lowers the right, which moves the plane to the left. The reverse tilt happens when the stick or wheel is moved to the right.ElevatorsElevators are used for pitching movement around the lateral axis. A backward pull on the control stick or wheel column raises the elevators, which moves the tail down and lifts the nose of the plane for a climb. Forward movement of the stick or column makes the plane dive.PropulsionInternal Combustion EnginesThere are two types of internal combustion engines, the reciprocating engine and the compound engine. In the reciprocating engine, heat energy is used to move pistons operating within cylinders. The cylinder arrangement is usually in-line, horizontal-opposed, or radial. They either use air-cooling or liquid-cooling systems. Nearly all aircraft reciprocating engines are gasoline operated. The advantages of the reciprocating engine are reliability and fuel economy.The compound engine consists of a reciprocating engine combined with an exhaust-gas turbine. It drives a supercharger which is an air compressor in the intake system of the engine. The advantage of the compound engine over the reciprocating engine is its high-power capacity at high altitudes.Jet EnginesThe various types of jet engines include: the turbojet, the turboprop, the ramjet, and the rocket engine. The turboprop and turbofan engines are modifications of the turbojet engine. They are gas turbine engines. The air that enters the intake of the engine is first compressed in a compressor. Fuel is then added to burn the oxygen in the air which increases the gas ...
