This is how a small airplane works taking as an example,
the most popular single-engine aircraft of all time, the Cessna 172. Welcome to JOYPLANES. A standard airplane is composed of the fuselage the wings, the empennage, the landing gear and the power plant. But there are a lot more components
involved. Let's start with the internal structure
of the airplane. The skeleton that underpins
the shape of the aircraft. The fuselage structure is made out
of aluminum formers, bulkheads, longerons and stringers. The main landing gear requires
to be made out of flexible steel to withstand the forces
during hard landings. If we look inside,
the wings we'll find rips which provide
the airfoil shape of the wing, spars running through the entire length
of the wings, accomplish great strength and stringers to support
the shape of the wing even more. The key point here
is that the shape of the airfoil is very specific to preserve the flight
characteristics of the aircraft and to produce lift efficiently and
with the least aerodynamic drag possible. The entire structure is covered with aluminum sheets
riveted to the skeleton. This outer skin will further increase
the strength of the airframe. This is called the airframe,
which is considered to be the entire structure,
minus the engine and avionics. The green color
of the skeleton structure (sometimes yellow) comes from a primer layer
of zinc chromate or zinc phosphate. It is applied to prevent corrosion
on the aluminum surfaces in most parts older models might not have
this layer of primer and will have the original aluminum and metallic look. This particular aircraft has wing struts to reinforce the joint
between the wings and the fuselage. It attaches from the main spar
to the lower front section of the fuselage because this aircraft has a high wing
configuration and headroom space in the cockpit
is limited, the full main spars
cannot go through the cockpit and instead there are a couple of spar
carrythrough channels that join the two wings together. Of course, these channels
are not as strong as the main spars, but that's when the wing struts come into play
to distribute the load and forces on the exterior of the airframe we'll see the static wicks
or static discharges attached to the sharpest points of the aircraft,
like the trailing edge of the wings. They discharge accumulated static
electricity back to the surrounding air while in flight. Without them, they static
electricity builds up and accumulates on other sharp extremities like the antennas, causing radio interference. Power Plant. The power plant includes the engine, propeller and other components. Different Cessna 172 models
can use different types of engines, all of them very similar in this model
where looking at the Lycoming io-360 a four cylinder
horizontally opposed piston engine that produces up to 225 horsepower. The engine not only rotates the propeller
to generate thrust, it also move
the alternator to produce electricity, a vacuum pump to
maintain gyroscopic instruments working. And we can also use the heat produced
by the engine to keep a comfortable temperature
inside the cockpit. This is also a four stroke engine, which means that each piston completes
a cycle of intake, compression, combustion and exhaust every two revolutions. At any given time each of the cylinders
in the engine is in a different stroke, meaning that there is always one cylinder
in the combustion stroke providing continuous power. The propeller is attached
directly to the crankshaft so that the power is directly transmitted
from the engine to the propeller without any gear reduction. This is also known as direct drive. The propeller in
this case is a fixed pitch propeller. It doesn't require as much maintenance,
and it's easy and cheap to replace. Like in many aviation engines, this engine is cooled by air taking air from the openings
on the nose of the aircraft and redirecting it through the heat-dissipating
structure of the cylinders or fins. Of course, the engine needs fuel to work and there are two different systems
to deliver the fuel to the engine, carburetor and fuel injection systems. The Lycoming io-360 uses fuel injection, which is a more modern system
with advantages over carburetors. The carburettor in the other hand, can
still be used in piston engine aircraft, but it's an older system and relies
more on mechanics than electronics. The goal of both systems is to provide
a mix of air and fuel to the cylinders during the intake stroke. The carburettor mixes the fuel and air
before it enters the cylinder. The amount of fuel that enters
the engine depends on the amount of air that is passing through it. Thanks to the Venturi Effect,
which generates a lower pressure that sucks the fuel
from the discharge nozzle. The fuel injection system
is more complicated but more efficient. It uses more components and relies
on electronic sensors to function well. It also needs to maintain fuel
pressure in the system. It constantly monitors
the amount of air and throttle setting to calculate
the precise amount of fuel that has to be injected
at the correct time. The injectors are located at the cylinder
heads and the fuel is not mixed with air until it is injected into the cylinder,
to ignite the fuel mixture each cylinder has two spark plugs, it uses two for efficient combustion
and also redundancy. The spark plugs generate a quick electric
discharge powered by the magnetos. There are two magnetos
also for redundancy and they rotate thanks to the engine. These magnetos are independent
from the electric system of the airplane. This is so that in case of an electric
failure, the engine can still run. The engine is mounted on a metal frame with some elastomeric mounts
to minimize vibrations. This assembly
attached to the main frame of the airplane fuel system. The Cessna 172 has a fuel tank on each wing. Each tank can store up to 28 gallons
for a total of 56 gallons or 211 liters. But only 53 gallons or 200 liters
are usable. The fuel used in
this aircraft is the 100 low lead grade aviation, which is blue in color. 100 grade can also be used, in which case it's
green. to refuel the aircraft First, the operator must connect
the grounding wire to the aircraft. The connection can be made at the exhaust
or the tied down ring under the wing, and then the available steps
will help the reach the top of the wings for refueling. The fuel is distributed from the tanks
through fuel lines that lead to a fuel selector
switch in the cockpit. With this which we can choose
to draw the fuels from both tanks, the left tank or the right tank. This can be used to balance the aircraft if there is one tank
with more fuel than the other. there is a small fuel reservoir to catch the fuel from a return line
from the engine. An electric auxiliary fuel pump is used
to prime the engine during the start up. Then the fuel goes through a filter
called the "gascolator" And finally,
an engine-driven fuel pump takes over during normal operation. The fuel tanks have a small
vent under the left wing, and it provides a pathway for the outside
atmospheric pressure to stabilize with the pressure inside the tanks. During flight, the incoming air will create a passive pressure
to facilitate the flow of fuel. Excess fuel can also drip from this vent. Control surfaces. The control surfaces are used to maneuver
the aircraft. The primary control surfaces
that you will find in all airplanes are the ailerons, the elevator and the rudder. The secondary control
surfaces are the flaps. Some aircraft will have more than one type
of secondary control surfaces. But in most smaller planes,
the flaps are enough. Let's go over the control
surfaces in detail. One by one, the ailerons are on the wings. They control the role of the airplane. When an aileron moves in one direction,
the other moves in the opposite direction. This generates
a difference of lift on the wings, more lift on one wing and a down
force on the other. Rolling the aircraft
to the desired direction. The ailerons are controlled by wires
connected to the main control hub, where they yokes are also connected, which, similar
to a steering wheel of a car, will move to ailerons and in turn the airplane
to the desired direction. This control
moves the aircraft in the longitudinal axis. The elevator is attached to the horizontal stabilizer
and the rudder to the vertical stabilizer. Like the ailerons,
they povit on their hinges. The elevator uses
the same mechanisms of wires to be controlled from the yokes. The wires run all the way
back to the empennage where they are linked to the elevator. This is what controls the pitch attitude of the plane to go up or down. To control it, you push up all the yoke. If you push on it, that will lower
the elevator pitching the aircraft down. And if you pull on it,
the opposite happens. This control moves the aircraft around its lateral axis. The elevator has an extra control
which is a trim tab, this is used to fine tune the elevator
during different phases of flight, and it counteracts the force
the pilot has to use to constantly push or pull to maintain
the aircraft's altitude. During takeoff it must be centered or as the
manufacturers recommend, for the aircraft. It is controlled with a vertical wheel
from the inside of the cockpit. The rudder is controlled with the pedals
to go to the left or right. This motion is called "Yaw" the yaw rotation happens
in the vertical axis. It is very important to maintain
that coordinated flight, especially during turns during flight the airplane uses all three control
surfaces to make constant adjustments if needed and to do any of the maneuvers, For example, to turn left, the ailerons
have to roll their airplane left. At the same time, the pilot has to apply
a bit of left rudder to compensate for adverse yaw,
and keep a coordinate a turn. On top of that, the pilot must begin
applying the right amount of elevator to make the airplane turn,
as well as to maintain the same altitude. The flaps are used to slow down
the aircraft and generate more lift at lower speeds. They effectively increase
the camber of the wings. These devices are mostly used during
takeoff and landings. They can be controlled from the cockpit with a lever switch
and they are electrically actuated. Flaps can only go down as opposed to the ailerons
that move up and down. They can lower in steps of 10, 20
and 30 degrees. Flaps can only be used
in a safe range of speeds. Exceeding the recommended speed for safe
use can compromise the structural integrity of the flap
mechanisms and the entire wing. The safe speed at which the flaps
can be operated in their different configurations
is indicated in the primary flight display or in the airspeed indicator
with a wide arc. It's important to note
that the primary control surfaces work more efficiently about certain speed. At lower speeds,
they lose control authority. Furthermore, at very low speeds, the airplane can enter a stall. Landing gear. This aircraft has a tricycle type
landing gear and it is fixed, meaning that the pilot won't have to worry about it
during takeoff and landing. This simplifies the construction
and maintenance of this airplane. The downside to this is the added parasite
drag during flight, which cumulatively will make the airplane
consume a small percentage of more fuel to minimize the parasite drag. The wheels can have aerodynamic pants
or fairings, and the main legs also have a streamlined shape. But some owners will remove the wheel pants
to facilitate maintenance of the wheels. The drag difference
can be considered negligible, but the use of wheel pants
certainly improve aerodynamic efficiency. The front wheel is controlled
by the pedals to steer on the ground. The pedals mechanism is connected
with push rods. The wheel also has a shock absorber
for suspension and another dampener on the side
called the "shymey damper" to avoid oscillations on its vertical axis
at high speeds on the ground. The back wheels have brakes that can be actuated
independently by use in the pedals. This can help control the direction
on the ground and, of course, slow down after landing. Notice
how the motion for moving the rudder and braking is different before
continuing with the rest of the systems. I just wanted to mention how challenging
the making of this video was. This video took a lot of research,
animation and logical thinking. I even learned some math and python code for the creation
of some animation drivers in Blender. Something that help me with these challenges was learning some math
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an annual premium subscription. Now let's continue with the cockpit. The cockpit area is where you as a pilot
or a passenger will sit. The pilot seats on the left front seat. There is also an area
where additional baggage can be loaded. This plane allows to carry up
to four adults, but it's all depending on the fuel and additional baggage loaded
as well as the weather conditions. The maximum takeoff
weight of these aircraft is 2,550 lb or 1157 kilograms. You can only take any useful load of 878 lb or 398 kilograms. The cockpit is also where you'll find all the instruments
and controls of the aircraft. In the instrument panel
we can see the primary flight display and the multifunction display. This plane is equipped
with the avionics system. Garmin G 1000 older aircraft will have gauges
and niddle indicators instead but they all accomplish the same task. Here's where the pilot finds
crucial flight data such as altitude, airspeed, altitude and engine gauges,
as well as GPS location. This information is the primary reference
for safe flying. One of the advantages
of the digital system is that it can be configured
to show the information you need in a convenient manner. The PFD shows their airspeed,
altitude, attitude, heading radio frequencies, vertical speed
and some other information. While the MFD will display the engine's
RPM, oil pressure and temperature, cylinders temperature and of course, available fuel and other
important gauges On the big area you can display the current
GPS location or other navigation charts, at the bottom there are three analog gauges
for redundancy. Should both of the screens fail in mid-flight
or an electric malfunction of some kind. These are the airspeed indicator,
attitude indicator and the altimeter. With these, the pilots should have enough
information to fly and make an emergency landing safely. The airspeed is gathered
from a device mounted under the left wing called the "Pitot Tube", the pitot tube
has a small hole where the air enters and is redirected
through pipes that go to both a computer and the analog gauge
to display the reading. If the plane is flying in icy conditions,
the heating element is activated to keep the pitot
clear of ice. Reading
the airspeed is extremely important. The altimeter and vertical speed
readings are taken from the static pressure port
located to the left side of the fuselage. If this fails, for some reason,
like getting clogged, a switch can open the valve
to read the pressure from the inside. Since the cockpit is not pressurized,
the pressure will be almost identical to the outside. The attitude indicator will show the bank
and pitch angles of the aircraft in real time. The digital version
shows it on the big screen and it uses an IMU internal measuring unit. But we still have the analog
one for redundancy and it uses a rotating gyroscope which is rotated
using the vacuum pump on the engine that will keep the instrument working,
if vacuum pressure is lost, the instrument displays a red mark
indicating no vacuum pressure. Side slip is also indicated in the PFD with a little trapezoidal shape
under the triangle. It indicates when the airplane
is making a side slip to either side. If it's not intentional by the pilot,
it must be corrected with the rudder. It can be more pronounced
during uncoordinated turns. The old analog version of their side slip
indicator looks like this. At the top, it is common to find
a redundancy analog compass. On the bottom left,
we can find electric switches for lights, auxiliary fuel pump,
avionics and master electricity. At the bottom,
we'll see the circuit breakers. Next to them is the ignition
switch and magneto selector. The airplane always operates in
both position to use both magnetos. In the center we have the main throttle
control of the engine and next to
it is the fuel mixture control. This makes the fuel mixture
richer or leaner, depending on the altitude or air pressure. The pilot will adjust the mixture control
for a more efficient combustion. The flap switch has the advised safe
range of operational speed. When the flaps are deployed
here, it indicates that the plane must go at hundred and ten knots or slower
to deploy the flaps at ten degrees and at 85 knots or less to extend them
from 20 to 30 degrees. To the right, we can see two knobs
to control the temperature and airflow inside the cabin. Down below, we see a fuel shut of valve in case of any fire,
this valve should be pulled out. And again, we see the fuel selector switch
and the elevator trim, which we have shown already. Lights and electric system. As we saw in the panel the lights can be switched on and off
here. Other electric systems
are also controlled from here. When the engine is not running,
the battery is the main source of power. An external power unit
can also be attached to the system. To get the engine running
will first need to engage the starter. This device will start rotating
the engine it draws a massive amount of current
from the battery. Such power is required
to rotate the engine the first time. Once the engine starts to produce its own
power from the combustion process, then the starter will retract
automatically. while the engine is running the alternator will provide the power to the aircraft
and the battery will be recharged. The aircraft's visibility is paramount, especially during the night. That's why this aircraft is equipped
with different lights. The beacon lights can be found
at the top of the vertical stabilizer. It's a red flashing light and it's turned on to alert the ground
crew that the engine is about to start and it can be switched off
when the engine has stopped. The strobe lights, also known as
Anti-collision lights, are white, flashing lights that improve the visibility
of the aircraft during the night. It warn another pilot in the area
of the presence of another aircraft they can be located at the wingtips
and in some models also at the back. The navigation lights, also known
as position lights are steady lights that show the position and direction
of the aircraft. on the left wingtip there is a red light on the right wingtip there is a green light. And at the back there is a white light
in different versions of the Cessna 172 this setup can be achieved
in different ways. But the law requires
all aircraft to meet certain standards. The landing and taxi lights in this model are located in the
leading edge of the left wing. They're used to illuminate
in front of the aircraft during takeoff and landing and during taxi on the ground. Although I tried to cover
as much as possible about the Cessna 172 in this video,
there are many more details I haven't mentioned much of what
I've learned about this amazing airplane is thanks to Pilot Institute
and its lead instructor, Greg. With their free
deep dive classes and free courses, you can start learning aviation right
away. Pilot Institute has collaborated
with the creation of this video. They have provided in-depth knowledge
and even 3D models. I've also personally helped Pilot
Institute develop a free virtual reality experience called Pre Flight Simulator,
in which you can interact with these machines
as if you were really standing there. You can check and see all the main components
and even look into the engine. In there you will see the Cessna 172,
the Piper Warrior and the Diamond DA40. It is available for free
at the Meta App Lab. As I said, they have collaborated
with the creation of this video. So they are not technically sponsoring
this video, but in my opinion, these guys are the go to choice
when it comes to pilot training. And if you plan to start your pilot
career, check all of the relevant links to Pilot
Institute in the description below. I hope you have enjoyed this video. Feel free to leave any of your comments
about these beautiful flying machine suggestions for future videos
or corrections about this video.
