1. The Wright Brothers

2. Chapter Overview The Wright Brothers Developing Aircraft
Chapter 2, Lesson 1

3. 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
Chapter 2, Lesson 1

4. Warm Up Questions CPS Questions (1-2)
Chapter 2, Lesson 1
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5. (Note to Instructor: Use “Pick a Student” button in CPS)
Quick Write
As you read in Chapter 1, the Wright brothers were the first to conduct a manned, controlled, sustained, and powered heavier-than-air flight.
Many others had tried unsuccessfully to do this. List the reasons for the Wrights’ success.
(Note to Instructor: Use “Pick a Student” button in CPS)
Chapter 2, Lesson 1

6. 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
Chapter 2, Lesson 1

7. Learning Check #1 CPS Questions (3-4)
Chapter 2, Lesson 1
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8. 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
Chapter 2, Lesson 1

9. 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
Chapter 2, Lesson 1
Courtesy of the Air Force Historical Research Agency

10. Step One: Unmanned Box Kite
They discovered that they didn’t 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
Chapter 2, Lesson 1

11. 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
Chapter 2, Lesson 1

12. 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
Chapter 2, Lesson 1
Courtesy of Wright State University

13. 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
Chapter 2, Lesson 1

14. The First Glider They also focused on airfoil—a wing’s 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 wing’s arc closer to the outer edge than to the center—to create greater stability and control
Chapter 2, Lesson 1

15. The First Glider
The brothers test-flew their glider at Kill Devil Hills in 1900
It didn’t crash, but clearly improvements were necessary
The Wrights headed back to Ohio to build the next version
Chapter 2, Lesson 1

16. The Second Glider (1901)
The first glider didn’t 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 couldn’t control it well when they tested it at Kill Devil Hills
It flew less than 300 feet—time to return to Dayton!
Chapter 2, Lesson 1

17. 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
Chapter 2, Lesson 1
Courtesy of Wright State University

18. Learning Check #2 CPS Questions (5-6)
Chapter 1, Lesson 1
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19. 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
Chapter 2, Lesson 1

20. The Third Glider The third glider had: This design was a success
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
Chapter 2, Lesson 1
Courtesy of NASA

21. 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
The 1903 Engine viewed from the side
Chapter 2, Lesson 1
Courtesy of the Library of Congress

22. 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
Chapter 2, Lesson 1

23. 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
Chapter 2, Lesson 1

24. 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
Chapter 2, Lesson 1

25. Anatomy of the Wright Flyer
Chapter 2, Lesson 1
Courtesy of Wright State University

26. How the Flyer Worked The brothers controlled their craft with:
the forward elevator
the use of wing warping
and a single, movable rear rudder
Surprisingly, the pilot did not sit upright
The pilot lay on his stomach in a padded cradle on the lower wing
Chapter 2, Lesson 1
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27. How the Flyer Worked
To the pilot’s 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
Chapter 2, Lesson 1

28. 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
Orville and Wilbur assembling the 1903 Flyer (detail)
Chapter 2, Lesson 1
Courtesy of “Wright State University

29. 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
Chapter 2, Lesson 1

30. 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
Chapter 2, Lesson 1

31. 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
Chapter 2, Lesson 1

32. The Wright Brothers’ Patent
Chapter 2, Lesson 1
Courtesy of the U.S. Air Force

33. 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
Chapter 2, Lesson 1

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 Selfridge—the first US military aviation casualty
Chapter 2, Lesson 1

35. Ways the Wright Brothers Contributed to Army Aviation
The brothers switched roles in mid-1909
Wilbur trained two pilots for the Army—1st 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
Chapter 2, Lesson 1

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
Chapter 2, Lesson 1

37. Learning Check #3 CPS Questions (7-8)
Chapter 2, Lesson 1
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38. 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 gliders—first flying them like a kite, then putting a man aboard
Chapter 2, Lesson 1

39. 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
Chapter 2, Lesson 1

40. 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
Chapter 2, Lesson 1

41. 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
Chapter 2, Lesson 1

42. Review Questions CPS Questions (9-10)
Chapter 2, Lesson 1
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43. 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
Chapter 2, Lesson 1

44. Next…. Done—the Wright brothers Next—developing aircraft
Chapter 2, Lesson 1
Courtesy of NASA