Hello friend, welcome back.
In this video, I will show you how an aircraft flies . As on today, aircraft is the fastest vehicle (Fig 1) to transport humans and goods across the globe. Have you ever wondered how does it fly. Lets see.
The important parts of an aircraft are shown in Fig. 2. THey are
In our world, if any object is free, it will try to reach the ground by moving downwards (Fig. 3). This is because of the attractive force exerted by the ground which is called gravitational forcce. So when the aircraft flies, there must be some force which acts against the gravitational force to make it float. That force is called lift force.
In aircraft, wings are the primary lifting surfaces. The difference in pressure between upper and lower surfaces of the wing creates the lift force. The pressure on the upper surface is lesser than the pressure on the lower surface. The net force will act in the vertical direction (Fig. 4). This force is called lift. When the lift force is greater than the weight of the aircraft, the aircraft will float in the air or go upwards. The pressure difference is created by the flow of air over upper and lower surface of wing.
Now you know how the aircraft is floating in the air. How does it move forward. Lets take an example of a bicycle. By pushing the pedal down you are giving a force which moves the bicycle forward. Similarly, the engines of the aircraft provide a force to push the aircraft forward. This force is called thrust of the aircraft.
Take the example of bicycle again. When you are going in a bicycle, when there is no wind, you would feel easier to push the bicycle. When there is a strong wind, you would feel difficult to pedal. It is because a force is acting against your movement. This force is called drag. Similarly, any object moving in the air will experience drag. The drag will act in the direction opposite to the movement of the aircraft.
Now you know four major forces acting on the aircraft (Fig. 5)
When the lift is greater than the weight, the aircraft will float. When the thrust is greater than the drag, it will move forward. Now you know how the aircraft flies.
To turn the aircraft different control surfaces (Fig. 6) are used. They are
To turn up and down, which is called pitching of an aircraft, the tail is used. When the control surface at the horizontal tail which is called elevator is deflected upwards, the aircraft will pitch up. When the elevator is deflected down, the aircraft will pitch down. Similarly, to turn left or right which is called yawing of an aircraft, the control surface on the vertical tail which is called rudder is used. When the rudder is turned toward the right or starboard side, the aircraft will turn toward right. When the rudder is deflected toward left or port side of the aircraft, the aircraft will turn left.
The wing has control surface named ailerons on both left and right wings. When the ailerons are defleced in different direction on both the wings, the aircraft will roll basd on the deflection. When the aileron is deflected the lift generated by the wing will vary. If the aileron is deflected down, the lift will increase. When it is deflected up, the lift will decrease. With the asymmetric deflection of ailerons in both wings, the lift generated by both the wings will be different. That difference in lift induces a moment about the centerline of the aircraft. Moment is nothing but the force multiplied by the distance. The net imbalance in moment will roll the aircraft (Fig. 7). To roll in the opposite direction, the direction of aileron deflection should be reversed.
All the control surfaces are controlled by the pilot at the cockpit. Generally there will be a yoke, alternatively known as a control wheel or a control column along with a pair of pedals (Fig. 8). When the yoke is moved forward or backward, the aircraft will pitch up or pitch down. When it is turned, the aircaft will roll. When the right pedal is pressed, the aircraft will turn toward right. When the left pedal is pressed, the aircraft will turn toward the left.
This is how the aircraft flies.
I hope this video is useful to you.
Thank you friend.