have you ever wondered how an airplane flies and how they are designed and built in this video with the help of 3D animation we're going to learn the basics of Aeronautical Engineering in great detail here's what we're going to learn first we'll take a look at all the parts of an airplane and see how the airframe is designed and built then we'll learn some basics of aerodynamic forces and air foils to see how lift is generated we'll then take a look at how airplanes are controlled in Flight with the of control surfaces along with all the mechanisms used to control them in the end we'll see how the landing gears the brake system and the navigation lights work and finish it off by studying the propulsion system of the aircraft so let's see how these magnificent Vehicles [Music] work the airplane model that I have chosen is a very popular homebuilt plane from Vans aircraft called rv14 I have modified the model a bit to make it easier for you to understand let's start with the parts of an airplane the body of the plane is called fuselage inside the fuselage you'll find the cockpit where the pilot sits and controls the plane and it is enclosed by a transparent fiberglass canopy the wings are attached to the fuselage along with fairings on the route as well as the tip of the Wings the forward most section of the plane holds the engine with a propeller and it is covered by two engine cowlings in the rear end of the plane a horizontal stabilizer and a vertical stabilizer is attached to the fuselage movable control surfaces like the ailerons and flaps are attached to the wings elevators are attached to the horizontal stabilizer and the rudder is attached to the vertical stabilizer this entire rear section is called the impen section this aircraft has three fixed landing gears where the wheels are covered by wheel fairings or wheel pants for aerodynamic purposes the entire aircraft is covered with thin aluminum sheets from the outside as well as from the inside and is called the skin of the aircraft these are the basic parts of an airplane let's see how they are built the fuselage is made of multiple supporting structures called bulkheads and formers and they are held together with the help of long rod-like structures known as lons and short strip-like structures called stringers these kind of small homebuilt airplanes are made of strong and lightweight materials such as wood composite materials and aluminum Alloys they are painted with corrosion resistant paint which gives them the distinctive green color the forward most bulkhead to which the engine is fixed is called a firewall it is made of fire resistant material like stainless steel to protect the occupants in the cockpit in case of a fire breakout in the engine section the outer and inner aluminum Skins are fastened to the airframe permanently by riveting the engine cowlings are made of composite materials due to its high strength lightweight and corrosion resistant properties the canopy is made of transparent fiberglass and it provides a greater field of view to the pilot the entire SC Al structure of the plane is called an airframe let's take a look at the wings two strong horizontal beams called Wings spars are attached to the fuselage their main purpose is to carry flight loads and the weight of the Wings on ground now comes one of the most important part of the Wings as well as the entire aircraft the ribs multiple ribs are permanently attached to the spars by riveting these ribs are designed in in a unique shape called air foil this shape creates an aerodynamic Force called lift which helps the airplane to fly and stay in the air we'll study about it in a moment the stringers provide additional strength and support to the ribs and the entire Wing behind the ribs the control surfaces such as the flaps and ailerons are attached to The Spar and both the surfaces are movable the wings are covered with fairings near the wing roots and the wing tips to reduce drag and they are made of strong and lightweight fiberglass material the wings not only generate lift they also carry fuel for propulsion some planes have fuel tank in their wings but in some planes there is no fuel tank the fuel is stored directly inside the wings these types of wings are called wet Wings they have to be perfectly sealed from the inside to prevent fuel leaks along with the fuel they also carry few mechanisms which are used to move the control surfaces let's see how the wings generate lift there are four forces acting on an airplane those are the lift weight thrust and drag lift is a force that holds the airplane in the air and most of the lift is generated by the wings weight is the force with which the gravity attracts a body in this case the airplane thrust is a force that moves the aircraft through the air the airplane engine provides the necessary thrust and the drag is a force that opposes the motion of the airplane in the air it is an aerodynamic resistance and it has to be avoided as much as possible the main aim of an aeronautical engineer is to design and build an aircraft while aiming to maximize lift and thrust and minimizing weight and drag as much as possible if you look at an airplane's Wing from the side it looks like this this unique shape is called an air foil the front end is called the Leading Edge and the rear end is called the trailing Edge If You observe carefully the top surface of the air foil is curved and the bottom surface is a bit flat this curve is called upper camber and this kind of air foil is called cambered air foil or asymmetric air foil another type of air foil called symmetric air foil is also used where the top and the bottom surface of the air foil has the same curvature these are the two main types of air foils and based on these two types hundreds of air foils have been designed and used they have to be chosen carefully depending on the altitude Speed and Performance You're Expecting from the aircraft you're trying to design to generate lift there must be air flow over the wings and to do that the airplane has to move forward the engine produces the necessary thrust and pushes the airplane forward once the airplane reaches a certain speed the air flow over the wing increases due to the camber on the up upper surface of the wing the air flow on top of the wing is moving faster than the air flow at the bottom of the wing this means that the air molecules on top of the wing are far away from each other whereas the air molecules at the bottom are closer to each other in other words the pressure on top of the wing is lower than the pressure at the bottom of the wing this difference in pressure creates an upward force on the wing and that force is called lift this is the famous Bern's principle also the air flow on the top surface of the wing is being deflected downwards near the trailing edge of the wing according to Newton's third law of motion for every action there's equal and opposite reaction this basically means that the downward flowing air is also pushing the wing upwards all these forces contribute in pushing the wing upwards which is nothing but lift here both Bern's principle and Newton's laws are in action this is an oversimplified explanation of the generation of lift in in reality it's a complex process we can increase and decrease the amount of lift generated by the air foil by increasing or decreasing the upper camber of the air foil we can do that by moving the control surfaces that are attached behind the wings and the stabilizers the lift can be increased by deflecting the control surface downwards this increases the upper camber of the air foil now the speed of the air flow over the upper surface increases causing the pressure to further decrease the pressure difference between the top and bottom surface of the air foil increases which increases the lift also the air is now being deflected at a steeper angle near the trailing Edge which also pushes the wing up similarly we can decrease the lift by moving the control surface up the air flow over the upper surface has now been disrupted this creates turbulence and decreases the lift on the air foil by increasing and decreasing the lift over the wings and the stabilizers we'll be able to turn the airplane in any direction we want an imaginary straight line passing through the middle of the air foil is called a cord line the angle between the cord line and the incoming air flow is called angle of attack when the airplane is flying straight and level as shown the angle of attack is zero the cambered air foil or the asymmetric air foil can produce lift at zero angle of attack because the difference in curvature between the upper and lower surface of the wing is enough to create the pressure difference required to generate lift whereas the symmetric air foils cannot produce lift at 0 degree angle of attack because both the upper and lower surface of the wing has the same curvature and therefore produces the same amount of pressure they simply fail to create pressure difference at zero angle of attack they'll produce lift only when the plane is flying at an angle of attack above 0° this is the main difference between symmetric and asymmetric air foils and this is exactly why the symmetric air foils are used in places like the horizontal and vertical stabilizers where lift is not required during most of the flight just like the wings the horizontal stabilizer also has spars and ribs but the difference is that the ribs used here have symmetric air foil pattern this is to avoid unnecessary pitching motion we'll study about these motions in a moment similarly the vertical stabilizer is also made of ribs with symmetric air foil pattern to avoid unnecessary yawing motion let's see how it works an airplane has three basic movements they are pitch roll and yaah when the plane's nose goes up and down it's called pitching when the entire plane tilts to one side it's called rolling when the plane's nose turn sideways it's called ya primary control surfaces such as the ailerons elevators and the rudder are used to turn the airplane in the desired Direction whereas the secondary control surfaces such as the flaps slats trim tabs and spoilers are used to improve the control and performance of the airplane let's see how they work inside the cockpit there is a control stick the pilot moves the stick to move the elevators and the aerons to pitch and roll the airplane elevators are used to achieve pitching motion pulling the stick back moves the elevator up pushing the stick forward moves the elevator down the stick is connected to a simple reverse motion linkage here the control rods are connected to a link that rotates about a fixed hinge when the stick is pulled back the control rods push the elevator [Music] up when the airplane is moving on the runway at high speeds the wings will generate lift but this is not enough for the plane to reach higher altitudes we need to tilt the nose of the plane up to help reach higher altitudes therefore the pilot pulls the stick back and the elevator goes up the air flow on the top surface of the horizontal stabilizer is now disrupted which reduces the lift on the horizontal stabilizer the horizontal stabilizer loses lift and the entire tail section goes down lifting the plane's nose up now the plane can Ascend to higher altitudes similarly when the pilot pushes the stick forward the elevator goes [Music] down this increases the camber on the upper surface of the stabilizer and increases the lift the tail section lifts up causing the nose to go down now the plane descends this is how pitching is achieved let's look at rolling aerons are used to achieve rolling they are located at the tip of the Wings they are arranged in such a way that when one aileron goes up the other one goes down and vice versa when the stick is moved to the left the left aileron goes up and the right aileron goes down this is because the control rods are pulling the left aileron up while pushing the right aileron down a simple Bell crank mechanism is used to achieve this motion this mechanism helps to turn the control Rod's motion by 90° the left aileron goes up and decreases the lift on the tip of the left wing whereas the right Aeron goes down and increases the lift on the tip of the right wing this imbalance in lift creates the rolling motion and causes the airplane to roll to the left similarly to roll to the right the pilot moves the stick to the right which lowers the left aileron and raises the right aileron now the lift on the right wing decreases and on the left wing increases making the airplane roll to the right we achieved rolling motion by varying the lift on the tip of the Wings let's look at yawing motion two pedals known as the rudder pedals are located near the Pilot's feet the pilot pushes these pedals to move the rudder to achieve yawing motion the pedals are connected to the rudder by two strong cables made of galvanized steel when the pilot pushes the left pedal the cable pulls the rudder to the left similarly pressing the right pedal will turn the rudder to the right to achieve left yaw the pilot pushes the left pedal and the rudder turns left this increases the camber on the right side of the vertical stabilizer and therefore increases the lift on the right side of the vertical stabilizer this will turn the tail section to the right and the nose of the plane turns to the left this is called Left yah here we are creating lift sideways similarly to achieve right yaah the pilot pushes the right pedal the rudder turns to the right and increases the lift on the left side of the vertical stabilizer creating right [Music] yaah by changing the camber on the air foil section we changed the lift distribution and successfully achieved pitching rolling and ya motion with the help of primary control surfaces like the ailerons elevators and the rudder let's look at one of the secondary control surfaces the flaps the flaps are located right next to the fuselage unlike the primary control surfaces the flaps only move downwards their main aim is to increase lift during takeoff and Landing by increasing the camber on the wings on the left hand side of the pilot there is a flap lever the pilot pulls the lever up to lower the flaps there is an angle indicator in the lever that shows what degrees the flaps are lowered at flaps are usually lowered between 25 to 40° when the pilot pulls the lever up the flaps goes down and increases the camber on the wings this increases the lift on the wings helping the pilot to control the aircraft during takeoffs and landings let's look at the landing gears this plane has three landing gears in a tricycle configuration the wheels are covered by wheel fairings or wheel pants to decrease drag these gears are fixed gears they cannot be retracted inside the fuselage the main gears are attached to the wings Spar they are made of strong composite materials and are made a bit flexible to absorb shock during hard Landings the nose gear is attached to the engine mount and it has a shock absorber it can turn to steer the airplane on the ground in other airplanes the nose gear is connected to the rudder pedals and they can be controlled directly but in this plane the nose gear rotates freely like a shopping cartwheel and it has to be controlled indirectly with the help of differential braking let's see how the brakes work both the main gears have hydraulic brakes which are controlled by the brake pedals the brake pedals are attached to the rudder pedals these pedals can rotate and are used to apply the brakes to stop the plane on the ground hydraulic brake cylinders with a piston are fixed right next to the brake pedals when the pedals are pressed they rotate and push the Piston inside the cylinder the brake fluid in the reservoir goes through the pipes and reaches the brake calibers now the brake is applied and the wheel slows down the brakes can be applied individually when the brake is applied on one wheel while the other wheel is spinning it's called differential brake King to steer the nose wheel to the right the pilot applies the brake on the right wheel the spinning left wheel will force the nose wheel to turn to the right similarly to steer to the left the pilot applies the left brake the spinning right wheel forces the nose wheel to turn to the left this is called differential braking and this is how the nose wheel steering is achieved in this aircraft colored lights known as navigation lights can be found at the tip of the Wings and on top of the vertical stabilizer you can find a Beacon Light the light on the right wing is of green color the left wing light is of red color and the Beacon Light is of white color these lights do not blink they are steady throughout the flight this is done to identify in which direction the plane is flying at night for example if you see the red light to the left and the green light to the right then the aircraft is flying away from you another set of white colored lights called strobe lights are designed to Blink and are used to make the plane more visible to other planes at night let's look at the propulsion section this aircraft uses a loming i39 4 cylinder internal combustion engine but the engine you are looking at is the UL 520 is engine this is a 5.2 L 6-cylinder internal combustion engine it weighs around 238 lb and produces horsepower of 200 hp and 465 Newton M of torque it rotates at 2,800 revolutions per minute in clockwise direction from the Pilot's view it uses minimum 95 octane Mo gas fuel which is stored in the wings the engine is mounted on the engine mount the mount is usually made of steel or aluminum and it's attached to the firewall two propeller blades are attached to the propeller Hub these blades are also made of air foil shapes placed in different orientations for increased thrust and reduced drag they are usually made of stainless steel Alloys aluminum Alloys and composite materials these are puller type propellers meaning they pull the aircraft forward there are planes with Pusher type propellers too they are usually placed at the back of the plane and they push the plane forward this propeller is a fixed pitch propeller there are variable pitch propellers too where the pilot will be able to change the angle of attack of the Blades by rotating them depending on the altitude at which the plane is flying by doing this the efficiency of the propeller and the engine is improved the exhaust gases from the engine goes out through the exhaust pipe which is located behind the engine the engine with the propeller provides the necessary thrust to push the aircraft forward in order to create more air flow over the wings and to keep the airplane in the air in this video we focused only on the lift in the future we'll learn about other important topics such as drag and different types of drags weight types of aircraft engines and types of secondary control surfaces you now know how an airplane flies thank you for [Music] watching