A Review on Airplane Parts and
Aerodynamics

Review On :-
1) Forces acting on the Aircraft (Four
Forces)
2) Bernoulli’s Principle
3) Airplane Parts
4) Debate whether Airplane can stay
stationary in air?

Forces:-
• Force – a push or a pull acting
on a body.
• As a plane flies it is in the center
of 4 forces.
– Weight, lift, drag and thrust
• Two natural forces being exerted
on plane
– Weight and drag
• A pilot needs to overcome
weight and drag to
achieve flight
• Two forces a pilot needs to
create to overcome weight and
drag
– Lift and thrust
• Lift & thrust are required to
keep the airplane in the air
Lift
Weight
Drag Thrust

Lift:-
• Lift is the upward force on a plane
– Various parts of a plane help to
achieve lift
• But most of the lift is created
by the wings
• The magnitude of lift depends on
the shape, size and velocity
– For example, the faster the
plane goes the greater the lift
• The lift that is produced by the
wings must be greater than the
weight of plane to leave the
ground.

Weight:-
• Weight is defined as the
downward force of gravity
– Force is always directed
toward the center of the earth
• Weight is distributed throughout
the plane
• The magnitude of the weight
depends on the mass of the
plane plus the fuel, the people
and baggage
• A pilot must overcome weight by
lift to get the plane in the air

Thrust:-
• Thrust is defined as the forward push
that gets the plane into the air
– Thrust is artificially created and used to
overcome drag and to sustain lift
• This force is provided by the propeller or jet
engine
• Thrust is also used to accelerate and
gain altitude

Drag:-
• Drag is a resistance force
created by the plane’s
movement through the air
– The force of the air pushes
against the plane, therefore
slowing the plane down
• The magnitude of drag
depends on the shape, air
quality and velocity
• Drag increases as air speed
increases
– A pilot must overcome drag with
thrust to gain speed

Engines (either jet or propeller) typically provide the
thrust for aircraft. When you fly a paper airplane, you
generate the thrust.

Important Concepts
Air
• Principal concept in aerodynamics is the idea that
air is a fluid
– Air has mass, therefore it has weight
• Because it has weight, it exerts pressure
– Air flows and behaves in a similar manner to other
liquids
– Air has molecules which are constantly moving
• Lift can exist only in the presence of a moving fluid
– Faster moving fluids exert less force on surfaces they
are flowing along

As an airplane moves forward, the airflowAs an airplane moves forward, the airflow
splits up into two separate flowssplits up into two separate flows
Before We Begin…

Bernoulli’sPrincipleDefined
• Bernoulli’s Principle states that when the
speed of a moving fluid increases, the
pressure decreases and when the speed
of a moving fluid decreases, the pressure
increases.

Bernoulli’sPrinciple
• Air flowing around the wing experiences a change in speed and each
change in speed is accompanied by a change in pressure
– Airflow going under the wing encounters a sloping surface
• Slows airflow down and slow moving air maintains a higher pressure on the bottom
surface
– Airflow going over the wing encounters the up/down sloping
• Slows the airflow down, then it speeds it up; with the faster moving air a lower
pressure develops on the below surface
– Air going over must travel farther, so its average speed is greater
than the speed of the air below
• Result: A reduction in sidewise pressure which
occurs at the top, exerting a lifting force on the
entire wing
• Pressure imbalance produces an overall
upward force

Bernoulli’s Principle
Diagram

Bernoulli’s Principle: Air moving over the wing moves
faster than the air below. Faster-moving air above
exerts less pressure on the wing than the slower-
moving air below. The result is an upward push on
the wing--lift!

Conservation of Energy
(Bernoulli’sPrinciple)
Bernoulli principle derived from the Law of Conservation
of Energy
• A fluid under pressure has potential energy.
– Energy can be stored in pressurized air
– The higher the pressure the greater the potential energy
• Moving fluids have both potential energy and kinetic energy.
– Total energy must remain constant,
so its potential energy decreases,
and which means its pressure
decreases as well
– When the air’s speed and
motional energy increase, the
pressure and pressure energy must decrease to compensate
• Speed increases over the wing because the airflow converts some
of its pressure energy into kinetic energy

Bernoulli’sTheory in Action
Air speeds up in the constricted space between
the car & truck creating a low-pressure area.
Higher pressure on the other outside pushes
them together.

The distance traveled is the same.
Equal distances in equal times means
the air is traveling at same speed.
There’s no net force=no lift.
The curved shape is a longer distance
so the air is traveling faster. Equal
distances traveled in equal times. No
net force=no lift.
The air on top is traveling faster. It
exerts less force. When 2 forces
are combined they do not cancel
each other out. Therefore there is
some net force upward.
Shape of the Wing
Bernoulli’s Principle

FactorsWhich Affect
theAmount of Lift Created
• Speed
– The faster the wing moves through the air the more air is forced over
and under
• So a plane must maintain ample velocity to keep the upward lifting force
– If it slows down too much—lift decreases—plane descend
• Density of air
– The denser the air the more lift (colder air is more dense; air density
changes with altitude)
• Planes climb better in winter.
• Shape of wing
– Asymmetrical
• Angle of attack (its tilt relative to the wind)
– Downside: increases drag

Various Parts of Aircraft

Airplane Parts
• Fuselage
• Wings
• Ailerons
• Flaps
• Rudder
• Horizontal Stabilizer
• Vertical Stabilizer
• Elevator

Fuselage
• The body of the airplane that all the other
parts are attached to.
• Can be made of many different substances
such as aluminum or wood.

Wings
• The part of the plane that creates lift and
controls roll.
• Has a rounded leading edge and tapered
trailing edge which helps create lift.
• The wing design uses Bernoulli’s Principle.

Yaw, Pitch, and
Roll
• Yaw – side to side
• Pitch – up and down
• Roll – rolling motion

Rudder
• Provides side to side control of airplane.
• Controls yaw.
• Used for maneuvers in the air and for taxiing
on runway.
Rudder

The RUDDER controls
YAW. On the vertical
tail fin, the rudder
swivels from side to
side, pushing the tail in
a left or right direction.
A pilot usually uses the
rudder along with the
ailerons to turn the
airplane.
Rudder Controls Yaw

Yaw Around the
vertical Axis

Elevator
• In line with and behind the horizontal
stabilizer.
• Controls pitch.
Elevator

The ELEVATOR
controls PITCH. On
the horizontal tail
surface, the
elevator tilts up or
down, decreasing
or increasing lift on
the tail. This tilts the
nose of the
airplane up and
down.
ElevatorControls
Pitch

Pitch Around the
Lateral Axis

Ailerons
• Located at the top of the trailing edge
of the wings.
• Controls roll.
• Move up and down to control the
direction of wind blowing over and
under it.

Ailerons Control Roll
The AILERONS
control ROLL. On the
outer rear edge of
each wing, the two
ailerons move in
opposite directions,
up and down,
decreasing lift on
one wing while
increasing it on the
other. This causes
the airplane to roll to
the left or right.

Roll Around
Longitudinal Axis

Horizontal Stabilizer
• Horizontal with the fuselage.
• Helps airplane maintain level flight.
Horizontal
Stabilizer

Vertical Stabilizer
• Vertical to the horizontal stabilizer.
• Helps to airplane maintain level flight.
Vertical
Stabilizer

Flaps
• Located near at the trailing edge of the
wing near the fuselage.
• The Flaps increase lift.
Flaps

Propeller
• Uses the principle of a wing to create
thrust to move the airplane forward.
• Can have different number of blades on
propeller.
• Design is similar to an airfoil.

Engine:-
• Turns the propeller at high RPM’s to
increase thrust.
Cessna
Skyhawk Engine Jet Engine

DEMONSTRATION ON
WORKING OF ENGINE

Landing Gear
• A frame with wheels that allow the plane to
takeoff and land.
• Some airplanes have retractable landing
gear. Landing Gear

Nose Gear
• The front landing gear when the plane
has three wheels to land.
Nosegear

• The short answer is - No, they cannot stop in mid-air.
Even though it appeared as the plane was not moving,
it is unlikely that its forward motion was completely
stopped. At a distance, very large planes can appear to
be nearly stationary, especially at the relatively low
speeds found during a landing approach. This effect can
be made much more apparent depending on the angle
from which you observe the plane - from the front or
rear, the apparent motion would be very small. The
distance from you to the plane also makes a
difference.
Whether Flight Can stay Stationary
in Air?

Whether Flight Can stay Stationary
in Air? – Cont.
• Air must be flowing past the wings in order to keep
the aircraft aloft.
• In very unusual circumstances, it could conceivably
remain stationary relative to the ground—if it were
flying directly into a very powerful headwind, for
example. That doesn't actually happen in practice,
however.
• But - it would take a very, very fast wind to keep
any airliner in the sky completely stationary - more
than 100 mph, probably. In a wind of that speed,
planes would not be taking off or landing.
Launch Video

• If there were no wind at all, then the ground
speed and the airspeed would be the same.
When a plane flies into the wind, the airspeed
is higher because of the added speed of the
blowing wind across the wings. If the wind were
blowing very hard, then the plane might have
sufficient airspeed to maintain the needed lift
to remain in the air, while the ground speed
could be very slow.
Whether Flight Can stay Stationary
in Air? – Cont.