1. Theory of Flight 6.03 Secondary Controls and
Secondary Effects of Controls
References:
FTGU pages 15, 28, 29

2. Review 1. What control surface causes roll?
2. What movement does the elevator create?
3. Which axis does yaw act around?
4. Name the 2 types of fuselage construction.

3. 6.03 Secondary Controls and Secondary Effects of Controls
MTPs:
Trim
Spoilers and Dive Breaks
Flaps
Secondary Effects of Controls
Coordination

4. Trim
Trim tab: adjustable device located on the trailing edge of control surfaces
Purpose – alleviates pressure on the controls
Other types of trim are bungees connected to the control column
Most often only on the elevator

5. Trim
The trim tab moves in the opposite direction as the control surface

6. Trim Trim in a glider Types - side trim (bungee) No trim tabs
- stick trim (ratchet)
Bungee Trim

7. Spoilers & Dive Brakes Primarily used in glider flying
Spoilers – are hinged plates on top of the wing
disrupt the airflow over the wing to “spoil” the lift (Top)
Dive Brakes – increase drag (Bottom)
NASA applet -

8. Spoilers & Dive Brakes
Purpose – allows the pilot to control the rate of decent during final approach and landing
- Spoilers and dive breaks increase drag and decrease lift

9. Flaps Increases the camber of the wing
This increases the lift and the drag
Known as a high lift device
Allows the aircraft to have a steeper approach path with a decreased stall speed
Allows glider pilot to fly slower in a thermal

10. Flaps
Types of flaps

11. Secondary Effects
The air movement over control surfaces when they are moved causes adverse effects
When you yaw you get Roll
When you roll you get Adverse yaw

12. Roll from Yaw Roll from yaw
When rudder is applied, the wing on the outside of the turn moves faster, which causes it to experience more lift
Faster = more lift

13. Roll from Yaw
MORE LIFT
CAUSES ROLL
TO THE LEFT
FASTER
YAW LEFT

14. Adverse Yaw from Roll
When ailerons are applied the plane has a tendency to yaw away from the lower wing because of aileron drag.
The wing that rises experiences more lift, but also more induced drag.

15. Adverse Yaw from Roll Right aileron UP MORE LIFT MORE DRAG ROLL CAUSES
Left aileron DOWN
LESS LIFT
LESS DRAG

16. Coordination
To turn the aircraft without causing unnecessary drag, aileron and rudder must be used.
Using too much rudder will cause a “skidding turn”.
Using too little (or opposite) rudder will cause a “slipping turn”.

17. Coordination
You slip in and skid out. Think of driving and skidding around a corner.

18. Confirmation How is adverse yaw created?
Why is there roll when an airplane is yawed?
What is the purpose of flaps?
Name 2 types of trim.
What is trim used for?
What is the difference between slipping and skidding?

19. Confirmation Draw on the airplane where the following go: Flaps
Spoilers
Elevator Trim tab
Aileron Trim tab

20. C-130 Deploying Flares