1 / 20

Theory of Flight Airplane Axes

Theory of Flight Airplane Axes. Reference. From the Ground Up Chapters 2.1.3, 2.1.4: The Axes of an Airplane, Stability Pages 23 – 26. Introduction.

ziazan
Download Presentation

Theory of Flight Airplane Axes

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. Theory of FlightAirplane Axes

  2. Reference From the Ground Up Chapters 2.1.3, 2.1.4: The Axes of an Airplane, Stability Pages 23 – 26

  3. Introduction • There are three axes around which an airplane moves. Each run through the C of G, are controlled by the pilot, and are stabilized by features in the aircraft.

  4. Outline • Airplane Axes • Balanced Controls • Stability

  5. Airplane Axes Lateral Axis (wing tip to wing tip) Longitudinal Axis (nose to tail) Vertical (or Normal) Axis (vertical through C of G)

  6. Longitudinal Axis Movement around: Roll Controlled by: Ailerons Attitude: Left/Right Bank

  7. Lateral Axis Movement around: Pitch Controlled by: Elevator Attitude: Nose Up/Down

  8. Vertical Axis Movement around: Yaw Controlled by: Rudder Attitude: Nose Left/Right

  9. Balanced Controls • Control surfaces sometimes balanced to help pilot move them and reduce flutter • Inset Hinge/Horn Balance • Part of control surface in front of hinge • Airflow helps pilot to move it • Mass Balance • Streamlined mass in front of control surface hinge • Reduces flutter

  10. Balanced Controls Horn Balance Mass Balance

  11. Stability • Stability • Tendency of an airplane in flight to remain in straight, level, upright flight and to return to this attitude, if displaced, without corrective action by pilot • Inherent Stability • Stability from design features of an aircraft • Affected by weight and C of G

  12. Stability Static Stability Initial tendency to return to original position Dynamic Stability Overall tendency to return to original position, after series of oscillations Straight flight disturbed by upward gust of wind

  13. Stability Negative Stability (AKA Instability) Aircraft moves further away from disturbed position Neutral Stability Aircraft continues in disturbed position Positive Stability Aircraft returns to original position Straight flight disturbed by upward gust of wind

  14. Longitudinal Stability = Pitch Stability = Stability around Lateral Axis = Corrects unwanted pitch Horizontal Stabilizer Airflow hitting stabilizer pushes aircraft back to original position if disturbed

  15. Longitudinal Stability Center of Gravity C of G affects nose up/down tendencies if too far rear/forward of C of P * Airplane must never be tail-heavy, or unable to recover from stalls

  16. Lateral Stability • Lateral Stability = Roll Stability = Stability around Longitudinal Axis • Dihedral • Angle that each wing makes with horizontal • If wing is displaced downwards, airplane slips into that direction causing more airflow to down going wing and lifting it • Keel Effect • High-wing aircraft have weight below wings acting as pendulum to return aircraft to original position if wing displaced • Sweepback • If aircraft is disturbed and a wing dips, lower frontward wing is exposed to more airflow • This creates more lift in frontward wing, thus picking it up

  17. Lateral Stability Keel Effect:

  18. Directional Stability = Stability around vertical/normal axis = Corrects unwanted yaw Vertical Stabilizer Airflow hitting vertical stabilizer pushes aircraft back to straight flight when disturbed

  19. Directional Stability Sweepback Airflow hitting one wing is more perpendicular to relative airflow, creating more drag and pushing it back

  20. Next Lesson 2.4 - Theory of Flight Flight Performance From the Ground Up Chapters 2.1.5, 2.1.6, 2.1.7: Flight Performance Factors, Airspeed Limitations, Mach Number Pages 26 - 33

More Related