Lecture

1. Principles of Flight Leading Cadet Training Control Lecture 5

2. Pilot Controls A pilot has 3 main controls to move the aircraft about its 3 axes. Ailerons, Elevators and a Rudder Using these controls the pilot can: Pitch – make the nose rise or fall Roll – make one wing rise and the other fall Yaw – make the nose move left or right Elevators Rudder Ailerons

3. The Pitching Plane Elevators make the aircraft nose rise or fall. They are hinged to the trailing edge of the tailplane, and linked to the pilots control column – ‘The Stick’

4. The Pitching Plane Angle of Attack Moving the stick forwards lowers the elevators, and gives an angle of attack which creates lift, and the aircraft is tail-up, nose–down, about its lateral axis. Lateral Axis Lift α Control Column Pushed Forward

5. The Pitching Plane Angle of Attack Moving the stick backwards raises the elevators, creating the opposite effect, and the aircraft is tail-down, nose–up, about its lateral axis. Lateral Axis α Lift Control Column Pulled Backward

6. The Rolling Plane Ailerons make the aircraft roll about its longitudinal axis. They are hinged to the trailing edge of each wing. and linked to the pilots control column – ‘The Stick’

7. The Rolling Plane Moving the stick to the left raises theLEFT aileron and depresses the RIGHT aileron. The left aileron has a reducedangle of attack and reducedlift The right aileron has an increasedangle of attack andincreasedlift The aircraft rollsto the left about its longitudinal axis. Lift Lift Control Column Pushed LEFT

8. The Rolling Plane Moving the stick to the right raises the RIGHT aileron and depresses the LEFT aileron, creating the opposite effect, and the aircraft rollsto the right about its longitudinal axis. Lift Lift Control Column Pushed RIGHT

9. The Yawing Plane The Rudder makes the aircraft nose move left or right. It is hinged to the trailing edge of the fin, and linked to the rudder pedals in the cockpit.

10. The Yawing Plane Moving the LEFT pedal forwards moves the rudderto the left, this produces a sideways force to the right. The tail is pushed to the right and the nosemoves to the left. New Flight Path Force Original Flight Path Rudder Pedals LEFT Forwards

11. The Yawing Plane Moving the RIGHT pedal forwards moves the rudderto the right, creating the opposite effect, Thetailis pushed to the left and the nosemoves to the right. Original Flight Path Force New Flight Path Rudder Pedals RIGHT Forwards

12. Trimming Tabs, Flaps & Slats The weight and position of an aircrafts Centre of Gravity can change when: Fuel is used, Bombs dropped, Ammunition fired, etc. The Centre of Pressure will also change due to: Change in Power, Speed and Attitude All these changes will affect the balance of forces on the aircraft There are a number mechanisms that assist pilots in these cases.

13. Trimming Tabs Rudder Trim Tab Aileron Trim Tab Aileron Trim Tab Elevator Trim Tabs Help comes in the form of ‘trimming tabs’, which are hinged to thetrailing edges of the elevators, ailerons andrudder. Larger Moment Arm + Pull Force + + + + + Stick Force Removed Stick Force Remains

14. Flaps An aircraft’s wing is designed so that the aircraft can make its approach at a controlled slow speed, along a moderately steep approach path. A well-proven solution is to add flaps for use on the approach and landing.

15. Flaps Flaps Flaps Flapsare hinged surfaces usually fitted to the trailing edge of wings before the ailerons to increase lift. Plain Flap (or Camber) 50% Increase CLMAX Critical Angle 12o Split Flap 60% Increase CLMAXCritical Angle 14o Slotted Flap 65% Increase CLMAXCritical Angle 16o Blown Flap 80% Increase CLMAXCritical Angle 16o Fowler Flap 90% Increase CLMAXCritical Angle 15o

16. Flaps Drag Effects on Flaps Flaps 30o Flaps 90o Flaps 60o Flap 30o 60o 90o Lift Large Inc Small Inc No Sig Inc Drag Small Inc Large Inc V Large Inc

17. Slats Slats Slats Slatsimprove handling at low speeds. They are small aerofoilspositioned along the leading edge of each wing. Open Slat 40% Increase CLMAX Critical Angle 20o Fixed Slat 50% Increase CLMAXCritical Angle 20o Droop Snoot Slat 50% Increase CLMAXCritical Angle 20o Kruger Slat 50% Increase LLMAXCritical Angle 25o Automatic Slat 70% Increase CLMAXCritical Angle 25o

18. Slats Direction of airflow Direction of airflow Slat If the wing reaches a high angle of attack, theslatopens. Air can now flow between the slatand the wing. The shape of the slot accelerates air through it improving the pattern of airflow over it.

19. Lift Augmentation CL (the ratio between lift and dynamic pressure). Effects on CL CL BASIC AEROFOIL SECTION TRAILING EDGE FLAP LEADING EDGE FLAP SLAT OR SLOT α

20. Check of Understanding In position 1 the aircraft is climbing vertically. To make the aircraft move to position 2 and then 3, Which way must the pilot move the control column? To the right To the left Backward Forward

21. Check of Understanding What control would a pilot use to make an aircraft roll? Aileron Fin Rudder Elevator

22. Check of Understanding On the diagram, what does the arrow point at? The elevator trimming tab The rudder trimming tab The fin The aileron

23. Check of Understanding What will happen if flaps are lowered during the approach to land? Drag will be decreased Lift will be increased A higher touch-down speed is needed The stalling speed will be increased

24. Check of Understanding Which of these diagrams represents a Fowler Flap? W X Y Z

25. Check of Understanding On this cross-section of a wing, which letter points to a slat? U T S R

26. Principles of Flight Leading Cadet Training End of Presentation