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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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.

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

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?

CP140 Aurora