1 / 49

Uncontrolled copy not subject to amendment

Uncontrolled copy not subject to amendment. Principles of Flight. Principles of Flight. Learning Outcome 2: Understand how the stability of an aeroplane is maintained in flight and how manoeuvrability is controlled Part 1. Principles of Flight. H Copter. A Bourne. C Tower. B Loons.

chun
Download Presentation

Uncontrolled copy not subject to amendment

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Uncontrolled copy not subject to amendment Principles of Flight

  2. Principles of Flight Learning Outcome 2: Understand how the stability of an aeroplane is maintained in flight and how manoeuvrability is controlled Part 1

  3. Principles of Flight H Copter A Bourne C Tower B Loons A Ship R Way Dan Winterland S Huttle I Flyum Revision

  4. Questions What is the force called that drives an aircraft forwards? Lift Weight Drag Thrust

  5. Questions What is the force called that resists the forward motion of an aircraft? Lift Weight Drag Thrust

  6. Questions If your speed is doubled, by how much would the Drag be increased? x2 x4 x6 x8

  7. Questions If Thrust = Drag and Lift = Weight then the aircraft is: Climbing Flying Straight & Level and Accelerating Flying Straight & Level an Decelerating Flying Straight & Level at Constant Speed

  8. Stability Objectives: • Identify the Axes of Rotation for an Aircraft. • Identify the Planes of Movement for an Aircraft. • Describe and Explain Stability in the 3 Planes of Movement. 4. Explain Dihedral and Anhedral and how they affect Stability.

  9. Stability OW!! What would happen to this dart when thrown? What would happen now? Something is needed to “Stabilise” the Dart (Aircraft).

  10. Stability Airflow Centre of Gravity (CG) Airflow ‘Body’ Ahead of CG is Destabilising. ‘Body’ Behind CG is Stabilising.

  11. Basic Stability Stable Unstable Neutral

  12. Basic Stability Stable • Forms of stability • Static - initial reaction • Dynamic - subsequent reaction

  13. Basic Stability Stable • Forms of stability • Static - initial reaction • Dynamic - subsequent reaction

  14. Basic Stability Stable • Forms of stability • Static - initial reaction • Dynamic - subsequent reaction

  15. Basic Stability Stable • Forms of stability • Static - initial reaction • Dynamic - subsequent reaction

  16. Basic Stability Stable • Forms of stability • Static - initial reaction • Dynamic - subsequent reaction

  17. Application to Aircraft StaticStability Unstable Neutral Stable

  18. Application to Aircraft Statically Stable Dynamic Stability Dynamically Neutral Dynamically Unstable Dynamically Stable

  19. Longitudinal Axis Yaw (Directional) Pitch (Longitudinal) Roll (Lateral) Lateral Axis Normal Axis Planes of Stabilisation

  20. Stabilisation AxisPlaneStability Longitudinal Rolling Lateral

  21. Stability

  22. Stabilisation AxisPlaneStability Longitudinal Rolling Lateral Lateral Pitching Longitudinal

  23. Stability

  24. Stabilisation AxisPlaneStability Longitudinal Rolling Lateral Lateral Pitching Longitudinal Normal Yawing Directional

  25. Stability

  26. DirectionalStability

  27. CG Directional Stability • Stabilising • Influence • of fin: • Value of Lift • Moment Arm Lift Flight Path Enhancement features: A large fin and/or a long moment arm Something causes the aircraft to yaw

  28. CofG Considerations An aft CofG requires a large Fin

  29. The strange case of the ever growing fins MOD

  30. Longitudinal Stability

  31. Longitudinal Stability Lift Flight Path Weight To explain this stability, we assume that the CP and CG are coincident.

  32. Longitudinal Stability Lift Lift Flight Path Weight Something causes the nose to rise Lift wings - Destabilising Lift tailplane - Stabilising Stabilising influence of Tailplane: Area x Moment Arm = Tail Volume

  33. Lateral Stability

  34. Lift Lift Weight Lateral Stability Resultant Sideslip

  35. Aircraft sideslips in this direction Lateral Stability Hdg All design features for lateral stability rely on the fact that bank results in sideslip

  36. Lateral Stability Methods 1. Large Fin of high aspect ratio (a big tall fin). Lift from fin rolls wings level

  37. Lift Lateral Stability Methods 2. Dihedral: Due to new direction of relative airflow – lower wing has higher AoA than upper - more lift - tends to roll wings level.

  38. Span Chord Aspect Ratio Lift Lateral Stability Methods 3. Sweepback More Less Less More Lower Higher More Less LOW WING

  39. Less Lift More Lift Lateral Stability Methods 4. High wing Air flow near wing roots affected by fuselage - Increases AoA on Low Wing -Decreases AoA on High Wing Relative Airflow

  40. Lateral Stability Methods 1. High Fin. 2. Dihedral. 3. Sweepback. 4. High Mounted Wing But too much Lateral Stability (High wing and Sweepback) very undesirable in fighter aircraft. Therefore anhedral to reduce the excess

  41. Any Questions?

  42. Stability Objectives: • Identify the Axes of Rotation for an Aircraft. • Identify the Planes of Movement for an Aircraft. • Describe and Explain Stability in the 3 Planes of Movement. 4. Explain Dihedral and Anhedral and how they affect Stability.

  43. Questions What are the 3 planes of an aircraft’s movement? a. Pitching, Lateral and Rolling. b. Pitching, Rolling and Yawing. c. Yawing, Longitudinal and Rolling. d. Longitudinal, Lateral and Normal.

  44. Questions Which one of the following will REDUCE Lateral Stability? Dihedral. A Large Fin. Sweepback. Anhedral.

  45. Questions What are the 3 Axes about which an Aircraft can move? a. Pitching, Lateral and Longitudinal. b. Pitching, Rolling and Yawing. c. Yawing, Longitudinal and Normal. d. Longitudinal, Lateral and Normal.

  46. Questions Which 3 Terms describe Static Stability? a. Stable, Neutral and Unstable. b. Stable, Rolling and Unstable. c. Yawing, Neutral and Stable. d. Neutral, Unstable and Pitching.

More Related