1. 6.06 Loads and Load Factor References: FTGU pages 17-18, 34-35
Theory of Flight
6.06 Loads and Load Factor
References:
FTGU pages 17-18, 34-35

2. Review
Where is the centre of pressure in straight flight, just before a stall and after a stall?
2. What are some factors that increase stalling speed?
3. What are the symptoms of a stall?
4. When can an aircraft stall?
Answers:
Just forward of the centre of the airfoil, near the front of the airfoil, at the back of the airfoil.
Forward C of G, turns, increased weight, turbulence
Buffeting, low airspeed, nose up attitude, stall horn, sloppy controls
If the critical A of A is exceeded, at any airspeed or altitude if the critical A of A is exceeded

3. 6.06 Loads and Load Factor MTPs: Definitions Load Factor changes
Load Factor in Turns
Forces in a turn

4. Weight
1. What is weight?
The downward FORCE due to gravity that acts opposed to lift
Acts through the centre of gravity

5. Weight Weight is greater than lift? Lift is greater than weight?
What happens if…
Weight is greater than lift?
Lift is greater than weight?

6. Loading
Gross weight of the aircraft divided by the area of lifting surfaces (wings)
2 Types
Live Load
Dead Load
= Load

7. Dead Load vs Live Load Dead Load
The load put on the aircraft when it is sitting on the ground. Weight due to gravity.
Live Load
Additional loads are added in flight due to acceleration or change in direction associated with manoeuvres

8. Load Factor Load Factor
Ratio of the actual load acting on the wings to the gross weight of the airplane
Live Load : Dead Load
In straight and level flight the load factor is 1

9. Load Factor Changes
The load factor is increased any time the aircraft is not in straight and level flight
Due to:
Performing aircraft manoeuvre
Wind Gusts
Turbulence

10. Load Factor Is loading a bad thing?....No but it could cause problems
1. Structural Limitation
Each aircraft is designed with a max load factor that should not be exceeded as permanent damage may occur
SGS 2-33a Max Load = 4.67 G
C152 Max Load = 4.4 G

11. Load Factor Load factor during flight Speed to reach critical angle of
2. Increased Stall speed
Increased load factor during manoeuvres in flight requires increased lift to maintain level flight
Critical angle of attack is reached at an increased speed
Stall speed increases
More on stalls in 6.07
Load factor
during flight
Speed to reach
critical angle of
attack
Stall
speed

12. Load Factors in Turns
As angle of bank is increased in a turn the load factor and amount of lift required also increases
Load factor increases exponentially with angle of bank
Angle of Bank
Load Factor
15°
1.04 G
30°
1.15 G
45°
1.41 G
60°
2 G

13. Forces in a Turn In a turn…
Lift is divided into two components = vertical and horizontal

14. Forces in a Turn Vertical component  opposes weight
Horizontal component  causes airplane to turn
This horizontal component is known as centripetal force

15. Forces in a Turn Resulting lift due to added horizontal components
Pulls plane into the
centre of the
turn
Resulting lift
due to added
horizontal
components
Pulls plane to
outside of
the turn

16. Centripetal versus Centrifugal Force
Forces in a Turn
Centripetal versus Centrifugal Force
Centripetal Force
Centrifugal Force
Pulls INTO the turn
Pushes AWAY from turn
Genuine force
Inertial (fictitious) force
This is the force you feel going around a corner in a vehicle. It pulls in the opposite direction of a turn.

17. Confirmation Fill in the blanks: Load factor =
What is the difference between live load and dead load?

18. Confirmation Label where the centripetal and centrifugal forces are.
If this aircraft is doing a 60 degree of bank turn, how many Gs is it experiencing?
When does an aircraft experience a 1G force?

19. CP140 Aurora