Downloaded 30 times
Uploaded byJini Raj
aircraft static and dynamic stability,longitudinal and lateral
This document discusses the theory of flight stability. It defines three types of stability - dynamic, static, and inherent stability. It then discusses the three axes of stability in more detail: longitudinal stability around the lateral axis affected by horizontal stabilizer and center of gravity position, lateral stability around the longitudinal axis created through dihedral, keel effect, and sweepback wings, and directional stability around the vertical axis provided by the vertical tail surface.
More Related Content
Similar to aircraft static and dynamic stability,longitudinal and lateral
aircraft static and dynamic stability,longitudinal and lateral
- 1. Theory of Flight 6.08Aircraft Stability References: FTGU pages 31, 32
- 2. Review 1. Define load. 2.What is the difference between live load and dead load? 3. What is the load factor in a 60O turn? 4. Describe the forces acting in a turn.
- 3. 6.08 Aircraft Stability MTPs: •Definitions • Longitudinal Stability • Lateral Stability • Directional Stability
- 4. Definitions Stability: How anaircraft reacts to disturbances while in flight Types of stability: • Dynamic (positive, neutral, negative) • Static • Inherent
- 5. Definitions Dynamic Stability – Theoverall tendency of an aircraft, when disturbed, to return to its original position Positive: airplane will return to its position Negative: airplane will tend to move further away from its position Neutral: airplane will neither return to its position nor continue to change
- 6. Definitions • Static Stability –The initial tendency of an aircraft, when disturbed, to return to its original position
- 7. Definitions Inherent Stability • Builtin characteristics to enable the airplane to be either stable or unstable • Stability may be built into each aircraft axis creating – Longitudinal stability – Lateral stability – Directional stability
- 8. Longitudinal Stability • Stabilityaround the lateral axis • Also known as pitch stability
- 9. Longitudinal Stability • Longitudinalstability is affected by: 1. Size and position of horizontal stabilizer 2. Position of the C of G
- 10. Longitudinal Stability Centre ofGravity (C of G) • C of G too far forward – Required loading on the horizontal tail surfaces to maintain angle of attack increases – Overall weight of aircraft increases – Stall speed increases
- 11. Longitudinal Stability • Cof G too far aft – Decreased longitudinal stability because centre of gravity is behind the centre of pressure – Violent stall characteristics – Poor stall recovery (very dangerous!) – Stall speed decreases
- 12. Longitudinal Stability A -C of G too far forward STALL SPEED INCREASES B - C of G too far aft STALL SPEED DECREASES
- 13. Lateral Stability • Stabilityaround the longitudinal axis • Also known as roll stability
- 14. Lateral Stability Lateral stabilityis created through 1. Dihedral 2. Keel effect 3. Sweepback wings
- 15. Lateral Stability Dihedral • Theangle that each wing makes with the horizontal of the aircraft • The lowered wing will produce more lift and will roll back into place • Downgoing wing • = greater angle of attack • = increased lift
- 16. Lateral Stability Keel Effect –When disturbed, weight of the aircraft acts like a pendulum to swing aircraft back into position – Natural feature of high wing aircraft – Weight of the aircraft lies under the wings
- 17. Lateral Stability Sweepback – Leadingedge of the wing slopes backward – When one wing is dropped, the lowered wing produces more lift than the raised wing and the original position is restored
- 18. Directional Stability Stability aroundthe vertical or normal axis
- 19. Directional Stability Vertical TailSurface (fin and rudder) • Airplanes have a tendency to fly directly into the relative airflow due to the vertical tail surface • When disturbed the relative airflow will hit the side of the vertical tail surface and push it back into position
- 20.
- 21.
- 22. Confirmation Match the axeswith the factors affecting them Longitudinal Stability Lateral Stability Directional Stability 1. Keel effect 2. C of G 3. Sweepback 4. Vertical Stabilizer 5. Horizontal Stabilizer 6. Dihedral
- 23. Confirmation What is thedifference between dynamic stability and static stability? How does dihedral affect lateral stability? How does the vertical stabilizer affect directional stability?
- 24.