1. Lesson 13: Aircraft Structures And Flight Controls

2. Aircraft Structures Truss-type Structures
Had struts and wire-braced wings
Occupants sat in open cockpits
Cockpits fabric-covered
Stressed-skin Structures
All of the structural loads are carried by the skin.
Thin wood skin
Or aluminum-alloy sheets

3. Aircraft Structures Monocoque Virtually no internal framework
Semi-monocoque
Internal arrangement of formers and stringers is used to provide additional rigidity and strength to the skin.

4. Semi-monocoque

5. Airframe Units: Fuselage Wings Stabilizers Flight control surfaces
Landing gear

6. Airframe Units: Vertical Stabilizer Horizontal Stabilizer Rudder
Elevator
Cowling
Flap
Aileron

7. Structural Loads/Stress
Five Types Of Stress
Tension
Compression
Bending force
Torsion
Shear force

9. Structural Loads/Stress

11. Structural Loads/Stress
Deformation
Nonpermanent Deformation
Deformation disappears when the load is removed.
Permanent Deformation
Wrinkles observed on top of wing and bottom of horizontal stabilizer.
Stretch marks on the bottom of the wing or top o the stabilizer. (positive g’s)

12. Materials For Aircraft Construction
Wood
Aluminum Alloys
Honeycomb
Magnesium
Stainless Steel

13. Materials For Aircraft Construction

14. Structures

15. Structures
Wing Construction Truss-type

16. Structures
Stressed-skin Wing Construction

17. Cantilever Wing

18. Control Surface Construction

19. Control Surface Construction
Control Surface Flutter
Control Surface must be mass balanced so that their center of gravity does not fall behind their hinge line.

20. Fuselage Construction
Truss Fuselage construction
Pratt truss
Warren truss
Stressed-skin Structure
Monocoque
Semi - Monocoque
Pressurized Structure

21. Flight Controls

22. Flight Controls

23. Pitch Control Elevators
Sole function is to change the angle of attack of the airplane, which alters its speed, lift and drag.

24. Pitch Control

25. Pitch Control Stabilator All-movable tail Anti-servo tab Ruddervators
Provides both longitudinal and directional stabilization and control.

26. Lateral Or Roll Control
Ailerons
Rolling action produced is the primary method of lateral control on most aircraft.

27. Lateral Or Roll Control

28. Directional Control Adverse aileron yaw
The aileron that moves downward creates lift and induced drag.
Induced drag pulls the nose of the airplane around in the direction opposite the way the airplane should turn.

29. Directional Control Rudder
Rotates the airplane about its vertical axis (Yawing)
Also provides a form of roll control because the application of rudder causes yaw which will induce a roll.

30. Directional Control

31. Trim Controls

32. Trim Controls Trim Tabs Balance Tab Anti-Servo Tab Servo Tab
Spring Tab
Adjustable Stabilizer

33. Trim Tabs

34. Balance Tab

35. Anti-Servo Tab

36. Servo Tab
Used on large aircraft when the control forces are too great for the pilot to manually move.
Flight control column moves the tab on the control surface and this aerodynamically moves the main control surface.

37. Adjustable Stabilizer

38. Fixed Trim Tab

39. Aerodynamically Balanced Control Surface
Overhang deflects to the opposite side of the fuselage from the main rudder surface to produce an aerodynamic force that aids the pilot.

40. Stall Strip and Vortex Generators

41. Auxiliary Lift Devices

42. Flaps
Change the camber of the wing and increase both its lift and drag for and given angle of attack
Moved by cables form an electric motor driven jackscrew.

43. Flaps

44. Leading Edge Devices
Delays the the airflow separation caused by a stall to a higher angle of attack.
Increases the energy of the air flowing over the surface.

45. Fixed Slot

46. Movable Slat