1. The Physics of Flight

2. Warm-Up Questions CPS Questions 1-2
Chapter 1, Lesson 2

3. Lesson Overview How lift is generated How weight affects flight
How thrust affects an aircraft’s movement
How drag slows an aircraft
How the four forces of flight interact with each other
Chapter 1, Lesson 2

4. Quick Write Octave Chanute’s expertise in designing
bridges gave him the know-how to tackle
some big questions in aviation, such as
the structure of biplane wings.
What skills have you acquired from school
that you could apply to a hobby?
(Note to teacher: Use “Pick a Student” button in CPS)
Chapter 1, Lesson 2

5. How Lift is Generated Upward force on aircraft against weight
Increasing aircraft’s forward motion
Increasing airfoil’s angle of attack – up to stall speed
Depends on aircraft’s shape, size, and velocity
Chapter 1, Lesson 2
Reproduced from NASA/Glenn Research Center

6. How to Control Lift
Pilots increase angle of attack to create more lift
Angle of attack and velocity must be balanced to keep flight path level
Air condition impacts the need for greater or lesser velocity to maintain lift
Chapter 1, Lesson 2
Courtesy of NASA/Kim Shiflett

7. Activity 1: Controlling Lift
Launch the airplane you created in Lesson 1 and observe the lift patterns
Document your findings and answer the questions on the worksheet provided
Chapter 1, Lesson 2

8. How Weight Affects Flight
Acts through single point center of gravity
Weight is a gravitational force on an object due to its mass
Mass includes airplane parts, fuel, passengers and freight
The more mass, the more resistance to moving
Chapter 1, Lesson 2
Adapted from NASA/Glenn Research Center

9. Weight’s Major Challenges
Overcoming an aircraft’s weight with lift
Pilots constantly adjust for balance during flight
Chapter 1, Lesson 2
Courtesy of NASA

10. Learning Check Questions CPS Questions 3-4
Chapter 1, Lesson 2

11. Activity 2: Center of Gravity Limit
Compute aircraft weight and center of gravity
Answer questions about your calculations of moment, weight, and center of gravity
Chapter 1, Lesson 2

12. How Thrust Affects an Aircraft’s Movement
Thrust is a forward force that moves an aircraft through the air
It’s opposite force is drag, the pull or slowing effect of air on an aircraft
Chapter 1, Lesson 2
Courtesy of USN/PH1 Richard Rosser

13. Where Thrust Comes From
Engines provide powered aircraft’s thrust
Thrust’s forward motion overcomes drag so airfoils produce lift
Chapter 1, Lesson 2
Reproduced from NASA/Glenn Research Center

14. Adjusting Thrust
Reduction in engine power while in level flight, drops thrust and aircraft slows
When two forces are equal, pilot will fly at constant airspeed
Chapter 1, Lesson 2

15. Adjusting Thrust, cont.
To maintain balance between lift and weight, pilot must coordinate thrust and angle of attack at any speed
Chapter 1, Lesson 2
Reproduced from US Department of Transportation/Federal Aviation Administration

16. How Drag Slows an Aircraft
As aircraft moves through air, its boundary layer changes the shape of airflow over the aircraft
Chapter 1, Lesson 2
Courtesy of Leon van Dommelen, FAMU-FSU College of Engineering

17. Types of Drag Parasite drag drains flight of needed energy
Form drag includes items like
antennas and engine covers
Interference drag occurs when
air currents flowing over
various angles of an aircraft
collide
Skin friction drag can include
anything on an aircraft’s skin
that allows air molecules to stick to
Chapter 1, Lesson 2
© Aaron Kohr/ShutterStock, Inc

18. Types of Drag, cont. Wingtip vortices produce induced drag
Air flows above the tip and comes back in a downwash behind the wing pulling down and back on aircraft
Chapter 1, Lesson 2
Courtesy of USAF/TSgt Russell E. Cooley IV

19. Learning Check Questions CPS Questions 5-6
Chapter 1, Lesson 2

20. Activity 3: : FoilSim III Lab
Conduct experiments on airfoils in a virtual wind tunnel using NASA’s
FoilSim III
Answer questions pertaining to your adjustments to lift and drag variables
Chapter 1, Lesson 2

21. How the Four Forces of Flight Interact with Each Other
If forces are balanced, aircraft cruises at constant velocity
If forces unbalanced, aircraft accelerates in direction of largest force
To maintain constant speed, thrust and drag must remain equal
For constant altitude, lift and weight must be equal
Chapter 1, Lesson 2

22. Activity 4: Four Forces of Flight
Label the appropriate force of flight on the worksheet illustration
Write a short statement describing the force’s affect on flight
Chapter 1, Lesson 2

23. Summary How lift is generated How weight affects flight
How thrust affects an aircraft’s movement
How drag slows an aircraft
How the four forces of flight interact with each other
Chapter 1, Lesson 2

24. Review Questions CPS Questions 7-8
Chapter 1, Lesson 2

25. Next…. Done – the physics of flight
Next – the purpose and function of airplane parts
Chapter 1, Lesson 2
Courtesy of USAF/CMSgt Gary Emery