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Articles: Controlling Flight

Pilots need to be able to steer an airplane as it moves through the air. Steering an airplane is not the same as steering a car. When you steer a car, the wheels of the car move to make it turn. Airplane wheels are used for take-offs, landings, and moving around the airport, but not to make the airplane turn in the sky. Instead, pilots use the shape of the airplane and the airplane’s surfaces to control how it flies.

There are three surfaces on an airplane that control its movement: the ailerons on the wings, the rudder on the tail, and the elevators on the tail. All of these control surfaces are like flaps. When they move, they change the way the air flows around the airplane. The flow of air changes how the airplane moves.

Elevators, rudder, and ailerons highlighted on a drawing of an aircraft.

Airplanes have a control stick instead of a steering wheel. It looks a bit like a joystick on a video game.

When the pilot moves the control stick to the right, the aileron on the right wing tilts up and the aileron on the left wing tilts down. The right aileron makes less lift when it tilts up and the left aileron makes more lift when it tilts down. The airplane then rolls to the side with less lift — in this case, to the right.

When the pilot moves the control stick to the left, the aileron on the left wing tilts up and the aileron on the right wing tilts down. The airplane rolls to the side with less lift, which is the left side this time.

Aileron on right wing tilts up and aileron on left wing tilts down causing airplane to roll rithr

The elevators at the back of the airplane control whether the nose at the front of the airplane points up or down. When the pilot pulls the control stick back, the elevators tilt up. This causes less lift, so the tail goes down. When the tail goes down, the nose goes up. This is called pitching up.

When the pilot pushes the control stick forward, the elevators tilt down. When the elevators tilt down, they create more lift in the same way that the ailerons do. This causes the tail to rise and the nose to point down.

Elevators tilt up causing airplane nose to pitch up.

The rudder is a vertical flap on the tail. It controls the sideways movement of the airplane’s nose to the left or to the right. This sideways motion is called yaw.

Two pedals at the pilot’s feet control the rudder. When the pilot pushes on the right pedal, the rudder tilts to the right. This makes the airplane’s nose yaw to the right because more lift is created on the right side. This extra lift pushes the tail to the left, which makes the nose yaw to the right. When the pilot pushes on the left pedal, the rudder tilts to the left. This makes the airplane’s nose yaw to the left.

Rudder tilts right causing airplane to yaw right.

Pilots have to use the ailerons and the rudder controls to turn the airplane. The whole flight path needs to curve, so the airplane must roll to the left or right while the rudder helps to keep it pointed in the proper direction. Otherwise, the force of air pushing against the control surfaces would make the airplane go off course.

When an airplane is flying in thin air, it takes longer to change direction when the control surfaces move. This is because there are fewer air molecules to push against.

 FirstGov  NASA
Editor: Brian Day
NASA Official: Liza Coe
Last Updated: September 2005
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