Fundamentals of Flight
A Basic Introduction to Aerodynamics
The Four Forces of Flight
The four forces act on the airplane in flight
and also work against each other.
The Four Forces of Flight
The four forces act on the airplane in flight
and also work against each other.
The earth’s gravity pulls down on
objects and gives them weight.
Weight counteracts lift.
What’s it take to create lift?
Air and motion.
How do we explain lift?
Newton’s Laws of Motion and
Bernoulli’s Principal are used to
explain lift.
Newton’s Second Law: force causes a change in
velocity which in turn generates another force.
Newton’s Third Law: net flow of air is turned down
resulting in an ‘equal and opposite’ upward force.
Newton’s Third Law states that for every action
there is an equal and opposite reaction.
Venturi Tube
Bernouli’s first
practical use of his
theorem
 Where are venturi
tubes used today?

Hold two sheets of
paper together, as
shown here, and blow
between them. No
matter how hard you
blow, you cannot push
them more than a little
bit apart!
Bernoulli’s Theory 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.
What is a wing?

A wing is really just
half a venturi tube.
A fluid (and air acts like a fluid) speeds up
as it moves through a constricted space
Bernoulli’s Principle states that, as air
speeds up, its pressure goes down.
Bernoulli's Principle: slower moving
air below the wing creates greater
pressure and pushes up.
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!
Bernoulli’s Principal: pressure
variation around the wing results in
a net aerodynamic pushing up.

http://www.grc/nasa.gov/WWW/Wright
/airplane/shape.html
A wing creates lift due to a combination
of Bernoulli’s Principal & Newton’s Third
Law
Interactive Wright 1901 Wind
Tunnel

Interactive Wright 1901 Wind Tunnel
Wing Shape

Internal ribs define
the wings shape
This US Navy Carrier Jet has a very small wing, how can
it fly? Can you see the airfoil?
Why is the wing small?
What other aerodynamic devices can you see?
How can an airplane fly upside down?

http://www.grc.nasa.gov/WWW/Wright/
airplane/incline.html
Pitch Around the Lateral Axis
Elevator Controls Pitch
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.
Roll Around Longitudinal Axis
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.
Yaw Around the vertical Axis
Rudder Controls Yaw
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.
Vectors: Two Kinds in Aviation

Vectors to final approach – instructions to a
pilot to steer a specific course “Turn left
heading 270, vectors to final approach course
Grand Junction.”

A physics term to define magnitude and
direction.
Vectors

A physics term to
define magnitude
and direction.
Direction: 045
Magnitude: 20
What?
20
45 o
Vectors
 20
What Units?
 Some unit of distance, force,
acceleration, time, etc.
Vectors
Vectors
Vectors

What good are
they? Or, “I was
told there would be
No Math!”

They help us find
out what happens!
Adding Vectors
together = Resultant
Vectors

Therefore, any
“vector” can be
“analyzed” or broken
down into horizontal
and vertical
components
Lift
Vectors: “The MATH”

Pythagorean

Properties
of right
triangles
Which of these airplanes will speed up?
Which will slow down?
Drag is the force of resistance an
aircraft ‘feels’ as it moves through
the air.
For an airplane to
take off, lift must be
greater than weight.
For an airplane to speed up while flying, thrust
must be greater than drag.
Engines (either jet or propeller) typically
provide the thrust for aircraft. When you
fly a paper airplane, you generate the
thrust.
A propeller is a spinning wing
that generates lift forward.
What will happen when the fire-fighting
plane drops its load of water?
AIRPLANE PARTS
Airplane Parts