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

3. Weight
1. What is weight?

4. Weight The FORCE due to gravity that pulls the aircraft to the ground
Acts through the centre of gravity (CG) of the a/c

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

6. Wing Area or Lifting Surface
Wing Loading
Aircraft Gross Weight
divided by
Wing Area or Lifting Surface
Types of Loads
Live Load
Dead Load
= Load

7. Dead Load v. 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 added in flight due to acceleration or change in direction associated with manoeuvres

8. 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 Is load factor a bad thing? Normally, No
But load factors could cause problems…

10. Load Factor Structural Limitation
Each aircraft is designed with a max load factor that should never be exceeded, as permanent damage or structural failure 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
Load factor
during flight
Speed to reach
critical angle of
attack
Stall
speed

12. Load Factor Changes
The load factor is increased any time the aircraft is not in straight and level flight.
Examples:
Aircraft Performing manoeuvres
Wind Gusts
Turbulence

13. Load Factors in Turns Angle of Bank Load Factor 15° 1.04 G 30° 1.15 G
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

14. Forces in a Turn In a turn lift is divided into two components
Vertical component
Horizontal component

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

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

17. Centripetal v. Centrifugal Force
Forces in a Turn
Centripetal v. 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.

18. Confirmation Check

19. Confirmation 1. Load factor =
2. What is the difference between live load and dead load?

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

21. CP140 Aurora