The primary flight controls are aileron,elevator and rudder. The pilot use these primary controls to intentionally maneuver the airplane on one or more axes. conventional flight controls consist of a control wheel or side stick and rudder pedals in the cockpit.
These controls wheel side sticks and rudder pedals are duplicated on the left and right. seats in the cockpit. The elevator and aileron are both moved by controls wheel or side stick.The rudder is connected to foot pedals. The Conventional flight controls are moved through a system of cables or rods.
In Delta winged aircraft "Elevon" a combination of ailerons and elevators is used. In some aircraft "Flaperon" a combination flaps and aileron is used for the roll. In V-tail aircraft "ruddervator" is used as rudders and elevators.
Elevator: The longitudinal control about its lateral axis is controlled by the elevators. This movement is called "Pitch". The elevators are movable surfaces hinged behind the tail plane(horizontal Stabilizer) may be at or near the top of the vertical tail plane or at the rear end of the fuselage. The elevators control the angle of attack of the wings.
When back pressure is applied (pull ) on the control wheel,the elevators are raised and nose rises,increasing the AOA. The reverse action takes place,when forward pressure is applied(push),the elevators are lower and nose lowers,decreasing the AOA. The elevators and stabilizer are located on either side of the fuselage near the tail of the airplane.
Aileron: The lateral control about its longitudinal axis is controlled by the two ailerons. This movement is called "Roll"
The ailerons are movable surfaces. They are hinged at outer trailing edge of each wing so that whwn one is moving upward on one wing the other aileron is downward on opposite wing. To turn left the pilot applies left pressure to the control column or side stick. Then the left aileron deflects upward and the right aileron deflects downward.
The force of the airflow is altered by these control changes ,causing the left wing to lower and the right wing to rise. This differential in lift causes the aircraft to roll to the left.
Rudder: Directional control about its vertical axis is controlled by the rudder. This motion is called "Yaw". The rudder is hinged vertically to the fixed surface vertical stabilizer or fin.
Pushing the right rudder pedal forward by the right foot will yaw the airplane to the right. Conversely if the left rudder pedal is pressed forward by the left foot the airplane will yaw to the left. The directional control is not used for turning the airplane in the normal condition of the flight. Pressure on the rudder is used to counter the adverse yaw. Rudder plays a big role to control the yaw during an engine failure on multi-engine aircraft.
Hydraulic (powered ) control: Because of the huge sizes of the primary control surfaces in the big aircraft,it will be impossible to move the control surfaces by the human force. Thus controls are boosted by hydraulically or electrically actuated systems as commanded by the pilot in the cockpit.
Fly-By-Wire: A fly by wire (FBW) systems replaces manual control of the aircraft with an electronic interface. The movements of flight controls are converted to electronic signals and flight control computers determine how to move the actuators at a each control surface to provide the expected response. The actuators are usually hydraulic,but electric actuators are also used.
The FBW system can save weight,improve reliability,These are carefully developed in order to produce maximum operational effect without compromising safety.
Artificial feel devices: With purely mechanical flight control systems,the aerodynamic forces on the control surfaces are transmitted through the mechanisms and are felt directly by the pilot. This gives feedback of airspeed and aids flight safety. With hydro-mechanical flight control systems, the load on the surfaces cannot be felt and there is a risk of over stressing the aircraft through excessive control surface movement. To overcome this problem artificial feel systems are used by a spring device to give increased resistance at higher speeds.
Elevator: The longitudinal control about its lateral axis is controlled by the elevators. This movement is called "Pitch". The elevators are movable surfaces hinged behind the tail plane(horizontal Stabilizer) may be at or near the top of the vertical tail plane or at the rear end of the fuselage. The elevators control the angle of attack of the wings.
When back pressure is applied (pull ) on the control wheel,the elevators are raised and nose rises,increasing the AOA. The reverse action takes place,when forward pressure is applied(push),the elevators are lower and nose lowers,decreasing the AOA. The elevators and stabilizer are located on either side of the fuselage near the tail of the airplane.
The ailerons are movable surfaces. They are hinged at outer trailing edge of each wing so that whwn one is moving upward on one wing the other aileron is downward on opposite wing. To turn left the pilot applies left pressure to the control column or side stick. Then the left aileron deflects upward and the right aileron deflects downward.
The force of the airflow is altered by these control changes ,causing the left wing to lower and the right wing to rise. This differential in lift causes the aircraft to roll to the left.
Rudder: Directional control about its vertical axis is controlled by the rudder. This motion is called "Yaw". The rudder is hinged vertically to the fixed surface vertical stabilizer or fin.
Pushing the right rudder pedal forward by the right foot will yaw the airplane to the right. Conversely if the left rudder pedal is pressed forward by the left foot the airplane will yaw to the left. The directional control is not used for turning the airplane in the normal condition of the flight. Pressure on the rudder is used to counter the adverse yaw. Rudder plays a big role to control the yaw during an engine failure on multi-engine aircraft.
Hydraulic (powered ) control: Because of the huge sizes of the primary control surfaces in the big aircraft,it will be impossible to move the control surfaces by the human force. Thus controls are boosted by hydraulically or electrically actuated systems as commanded by the pilot in the cockpit.
Fly-By-Wire: A fly by wire (FBW) systems replaces manual control of the aircraft with an electronic interface. The movements of flight controls are converted to electronic signals and flight control computers determine how to move the actuators at a each control surface to provide the expected response. The actuators are usually hydraulic,but electric actuators are also used.
The FBW system can save weight,improve reliability,These are carefully developed in order to produce maximum operational effect without compromising safety.
Artificial feel devices: With purely mechanical flight control systems,the aerodynamic forces on the control surfaces are transmitted through the mechanisms and are felt directly by the pilot. This gives feedback of airspeed and aids flight safety. With hydro-mechanical flight control systems, the load on the surfaces cannot be felt and there is a risk of over stressing the aircraft through excessive control surface movement. To overcome this problem artificial feel systems are used by a spring device to give increased resistance at higher speeds.
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