BASICS OF BRIEFING/ADDING THE POLISH

1
The Wright Brothers
2
Lesson Overview

• How the Wright brothers succeeded in the first
  flight
• The anatomy of the Wright Flyer
• The principles of airplane flight
• The history of the Wright brothers involvement
  with the US Army

3
How the Wright Brothers Succeeded in the First
Flight

• All pilots face three challenges
• Get up in the air
• Stay up
• Control the craft
• Pilots experimented in flight with
• Manned and powered, full-size aircraft
• Models
• Full-size gliders

4
How the Wright Brothers Succeeded in the First
Flight

• The Wrights chose a glider as their starting
  point
• They could focus first on balancing and
  controlling the aircraft
• Power (an engine) could come later
• They applied what they learned at each step to
  make the next one go more smoothly

5
Step One Unmanned Box Kite

• The Wrights kite had
• A five-foot wingspan and biplane structure
• Struts that connected the upper and lower wings
• Bracing strung diagonally between the struts

Courtesy of the Air Force Historical Research
Agency
6
Step One Unmanned Box Kite

• They discovered that they didnt need to tilt an
  entire wing to turn the craft
• Needed to twist only the ends of the wings
• They called this process wing warping
• In the summer of 1899, Wilbur Wright successfully
  tested the kite in a field

7
Step Two Manned Gilders

• Between 1900 and 1902, the brothers built three
  gliders
• Before putting a man aboard, they flew each
  glider like a kite
• They wanted to test it for control and lift
• Only after doing this would they put a man aboard

8
Wright Gliders

• The early glider experiments taught the brothers
  three important things
• How to control climb and descent
• The best design for the shape of the wing
• How large the wing area had to be to sustain lift

Courtesy of Wright State University
9
The First Glider (1900)

• In their experiments in 1900, the Wrights placed
  an elevator at the front of the glider
• Earlier designers mounted elevators behind the
  wings
• But the Wrights found it easier to control climb
  and descent when the elevator was placed forward

10
The First Glider

• They also focused on airfoila wings profile
• Zeroed in on curve of the wing
• Tried to design a wing that shifted the center of
  pressure toward the front edge of the wing
• Placed the highest point of the wings arc closer
  to the outer edge than to the centerto create
  greater stability and control

11
The First Glider

• The brothers test-flew their glider at Kill Devil
  Hills in 1900
• It didnt crash, but clearly improvements were
  necessary
• The Wrights headed back to Ohio to build the next
  version

12
The Second Glider (1901)

• The first glider didnt have nearly enough lift
• So for their 1901 glider, the brothers increased
  the wing area to 290 square feet
• This glider was also a big disappointment
• The brothers couldnt control it well when they
  tested it at Kill Devil Hills
• It flew less than 300 feettime to return to
  Dayton!

13
The Wind Tunnel

• The brothers built a wind tunnel in their bicycle
  shop to test model-size wings
• Made them of sheet steel
• Cut more than 200 model wings of different shapes

Courtesy of Wright State University
14
The Third Glider (1902)

• This glider had two fixed, vertical rudders
  behind the wings
• Test flights showed that this resulted in erratic
  behavior during turns
• So the Wrights tried a single, movable, vertical
  rudder
• This improved control

15
The Third Glider

• The third glider had
• Forward elevator
• Elliptical shape
• Longer, skinnier wings
• Wing area of 305 feet
• Low angle of attack
• This design was a success
• The brothers took to the air in the North
  Carolina dunes more than 700 times in the fall of
  1902

Courtesy of NASA
16
Step Three A Manned, Powered Aircraft

• The brothers set out to fit their plane with an
  engine
• They tried to buy one ready made
• But no one met their needs or price
• So they had their bicycle mechanic, Charles E.
  Taylor, build them a four-cylinder, 12-horsepower
  engine

Courtesy of the Library of Congress
17
Delays

• In September 1903 they returned to Kitty Hawk and
  Kill Devil Hills
• First they had to build a trolley track to give
  their powered aircraft a running start
• Bad weather also caused delays
• The brothers tossed a coin, and Wilbur won
• However, on the first test flight of the Wright
  Flyer, he crashed it
• It took three days to repair the damaged craft

18
First Flight!

• On 17 December, Orville took the controls
• The Flyer rose into the air and stayed aloft for
  12 seconds and traveled 120 feet
• Orville had made the first controlled, sustained,
  heavier-than-air human flight with a powered
  aircraft
• The brothers took turns piloting the Flyer for
  three more flights
• The fourth and final launch lasted 59 seconds,
  and the craft traveled 852 feet

19
Anatomy of the Wright Flyer

• Equipped with an engine and propellers
• Biplane with wingspan of 40 feet, four inches,
  and a wing area of 510 square feet
• Wings had spars and ribs (covered in muslin)
• Struts and bracing between top and bottom wings
• Plane also had a front elevator
• Rudder at the rear (covered in muslin)
• Skids rather than wheels

20
Anatomy of the Wright Flyer
Courtesy of Wright State University
21
How the Flyer Worked

• The brothers controlled their craft with
• the forward elevator (controls up and down
  movement)
• the use of wing warping (change of wing shape to
  change dynamics of flight)
• and a single, movable rear rudder (right and left
  movement)
• Surprisingly, the pilot did not sit upright
• The pilot layed on his stomach in a padded cradle
  on the lower wing

Courtesy of Comstock Images
22
How the Flyer Worked

• To the pilots left was a lever that he used to
  control the up-and-down movement of the elevator
• By moving his hips, he pulled on the cables
  connected to the wings and rudder (directing the
  plane left or right)
• With the new, flexible rudder, the plane finally
  turned in the intended direction
• The cables attached to the wings twisted one wing
  down while forcing the other wing up

23
Principles of Airplane Flight

• To get the Wright Flyer off the ground, the
  brothers had to solve the principles of flight
• Lift
• Drag
• Thrust
• Angle of attack
• Center of pressure
• Airfoil
• Relative wind

Courtesy of Wright State University
24
Principles of Airplane Flight

• Lift a reduction of air pressure on the upper
  part of a wing, while the air pressure on the
  bottom remains the same. The difference in
  pressure accounts for the upward force.
• Drag a force that opposes the forward motion of
  the aircraft the point at which the lift is no
  longer sufficient to stay in the air

Courtesy of Wright State University
25
Principles of Airplane Flight

• Thrust a force that propels the aircraft
  forward
• Angle of attack one of the factors that
  determines the aircrafts rate of speed through
  the air, in conjunction with the wing angle and
  its relationship to the wind path

Courtesy of Wright State University
26
Principles of Airplane Flight

• Center of pressure a point where the pressure of
  air over the airfoil/wing is equal all around it
• Airfoil a part of the aircraft, typically the
  wing or shaped like the wing, designed to produce
  lift
• Relative wind the wind moving past the airfoil
  is parallel to the flight path and the angle of
  the airfoil

Courtesy of Wright State University
27
Principles of Airplane Flight

• An engine and propellers gave Wilbur and Orville
  the ability to use not only lift but also thrust
  to propel their plane
• Vertically mounted propellers could provide the
  airflow for thrust
• They needed 90 pounds of thrust to propel the
  Wright Flyer
• Their 12-horsepower engine and the large
  propellers proved equal to the task

28
Wright Brothers Involvement With the US Army

• The Wright brothers continued refining their
  airplane
• In January 1905, they had contacted their
  representative in Congress (R. M. Nevin) and
  tried to interest the US government in buying
  their airplane
• Their offer was turned down

29
Wright Brothers Involvement With the US Army

• The British and French governments were
  interested in buying the Flyer
• But the brothers wanted the US government to have
  the first crack at owning a Wright Flyer
• On 22 May 1906 they received a government patent
  for their invention

30
The Wright Brothers Patent
Courtesy of the U.S. Air Force
31
Bids for a Government Plane

• On 23 December 1907, Gen James Allen sent out a
  request for bids to build a plane for the
  government
• The Wright Flyer met the bid requirements
• Orville Wright signed a contract on 10 February
  1908 selling the Flyer to the US government

32
Bids for a Government Plane

• Bid Specifications
• The flying machine should have a speed of 40
  miles per hour
• That it be capable of carrying two people, whose
  combined weight would equal about 350 lbs.
• Has sufficient fuel for a nonstop flight of 125
  miles
• Be controllable in flight in any direction
• Capable of endurance flight of 1 hour, and it
  land at its takeoff point without damage so that
  the flight could continue immediately

33
Bids for a Government Plane

• Bid Specifications continued
• The starting device had to be simple and
  transportable
• The plane had to be capable of landing in a field
  without requiring a specially prepared spot and
  without damage to its structure
• Train two pilots

34
Ways the Wright Brothers Contributed to Army
Aviation

• Orville spent much of 1908 and 1909 improving the
  Flyer
• He made more test flights and took up military
  passengers
• One such flight tragically ended in a crash that
  seriously injured Orville and killed 1st Lt
  Thomas Selfridgethe first US military aviation
  casualty

35
Ways the Wright BrothersContributed to Army
Aviation

• The brothers switched roles in mid-1909
• Wilbur trained two pilots for the Army1st Lt
  Frank P. Lahm and 2d Lt Fredric E. Humphreys
• A third pilot, 1st Lt Benjamin Foulois, got
  instruction late that month
• Foulois went on to achieve the rank of major
  general and was also chief of the Army Air Corps

36
Army Airplanes

• It took a while for the Army to decide how to use
  airplanes during war
• At first, the Army thought that airplanes would
  be useful only for aerial reconnaissance
• World War I brought about a change in strategy
• But before that could happen, airplanes needed
  improvements to make them faster, sturdier, and
  more reliable

37
Review

• The Wrights choose a glider as their starting
  point
• They began in July 1899 with an unmanned box kite
• Between 1900 and 1902, the brothers built three
  glidersfirst flying them like a kite, then
  putting a man aboard

38
Review

• The early glider experiments taught the brothers
  three important things
• How to control climb and descent
• The best design for the shape of the wing
• How large the wing area had to be to sustain lift
• Once the Wrights had resolved questions about
  control and lift, they set out to fit their plane
  with an engine

39
Review

• On 17 December 1903 Orville made the first
  controlled, sustained, heavier-than-air human
  flight with a powered aircraft
• The brothers controlled their craft through three
  main means
• The forward elevator
• The use of wing warping
• A single, movable rear rudder

40
Review

• On 22 May 1906 the brothers received a government
  patent for their invention
• On 10 February 1908 they sold the Wright Flyer to
  the US government
• It took a while for the Army to decide how to use
  airplanes during war
• Airplanes needed improvements to make them
  faster, sturdier, and more reliable

41
Summary

• How the Wright brothers succeeded in the first
  flight
• The anatomy of the Wright Flyer
• The principles of airplane flight
• The history of the Wright brothers involvement
  with the US Army