Principles of Flight

1. Principles of Flight Leading Cadet Training Resources

2. Principles of Flight Learning Outcome 3: Know the principles of stalling

3. Principles of Flight Revision

4. Questions • What effect does a Trailing Edge Flap have on the Stalling Speed? • Higher. • Lower • c. The same. • d. No difference.

5. Questions • One type of Leading Edge Flap is: • Plain. • Slot. • c. Split. • d. Krueger.

6. Questions What are some of the High Lift Devices on the Leading Edge called? a. Plain Flaps. b. Ailerons. c. Slats. d. Split Flaps.

7. Stalling • Objectives: • Describe the Stall in terms of Lift. • State the generally used Critical or Stall Angle of Attack. • Understand the relationship between Stalling and Airspeed. • State where the Pilot obtains information regarding the Aircraft’s Stalling Speed. • 5. List the Factors which affect the Stalling Speed.

8. The Stall • It is vital for a pilot to understand and be able to spot a stall while flying. • This will be most important while performing high “g” manoeuvres (aerobatics) or while flying at slow speeds, such as takeoff or landing. • The stall is when the airflow over the wing becomes turbulent, usually due to a too high angle of attack, or too slow a speed.

9. Stalling Angle • This is the angle of attack (chapter 1) of the wing. • Above the angle of best climb, usually around 15° for a conventional wing, the airflow over the wind becomes turbulent and cause a stall. • This angle is always the same on the same aircraft.

10. Stalling Speed • Unlike the stalling angle, the speed for stalling an aircraft does vary. • The data on the stall will be available on the Pilot’s Notes for each aircraft.

11. Stalling Speed • Factors affecting the stall are: • Weight: The heavier the aircraft, the higher the stalling speed (i.e. the speed at which the aircraft stalls) • Power: The more power used, the lower the stalling speed. • Flaps: When lowered these reduce the stalling speed (Chapter 3) • Ice: Ice on the wing can alter the shape of the wing, and hence it is made less efficient, so the stalling speed increases. • Damaged Wings: Again, as the shape is altered, the wing is less efficient, hence the stalling speed increases. • Manoeuvres: In a turn (for example) the wing looses some of its vertical lift component, hence it can support less of the aircrafts weight. This again increases the stalling speed.

12. Attitude and the Stall • The wing can stall in any attitude, whether it be vertical, turning, upside down or even straight and level. • It is the angle of attack of the wing which affects the stall.

13. Questions • What happens to Lift when a Wing is Stalled? • Lift Increases as Angle of Attack Decreases. • Lift Decreases as Angle of Attack Increases. • Lift is Greatly Reduced. • Lift Remains unchanged.

14. Questions • The Critical Angle of Attack is Generally about? • 5o. • 15o. • 25o. • 35o.

15. Questions • Which of the following will NOT REDUCE the Stalling Speed? • Extra Weight. • Larger Wing Area. • Flaps Lowered. • Flaps Raised.

16. Look Head • Your Next Lesson Will Cover Gliders