Four forces acting on an airplane
Lift
Weight
Thrust
Drag
Elements of an airfoil
Leading edge
Trailing edge
Upper camber
Lower camber
Chord line
Angle of attack
Any surface such as a wing, rotor blade or propeller which produces an aerodynamic force when it passes through a stream of air
Airfoil
Characteristic curve of the aerofoils upper and lower surfaces
Camber
Describes a convex sruface
Positive camber
Describes a concave surface
Negative camber
Low speed wing generally have a _____ camber
Large, positive
High speed wings generally have a ______ camber
Small, positive
AOA
Angle of chord line in relation to the relative wind
Describe the relation b/t AOA, lift, and velocity
Lift = V2 (AOA)
Straight and level, unaccelerated flight; Maintaining altitude and constant speed
Equilibrium
Aerodynamic stall
Exceeding the critical AOA
What do you need to enter a spin
Stall and Yaw
Controlling lift
Aircraft design
Pilot - change angle of attack, airspeed, shape of wing
4 types of flaps
Plain
Split
Fowler
Slotted
Rear portion or airfoil rotates downwards on a simple hinge mounted at the front of the flap
Plain flap
Rear portion of the lower surface of the airfoil hinges downwards from the leading edge of the flap, while the upper surface stays immobile
Split flap
Slides backwards flat, before hinging downwards, thereby increasing first chord, and then camber
Fowler flap
Gap between the flap and the wing forces high pressure air from below the wing over the flap helping the airflow remain attached to the flaps, increasing lift compared to a split flap
Slottted flap
The separation of airflow from the airfoil resulting in the loss of lift
Stall
Explain stall recovery
Decrease angle of attack
Smoothly apply max power
Adjust power as needed
Recover to level flight
Aggravated stall resulting in corkscrew path; One wing more stalled than the other
Spin
Load factor ratio`
Load supported by the wings to Actual weight of the aircraft and contents
Load factor ________ as angle of bank increase
Increases
Increasing lead factor will cause an airplane to...
Stall at a higher speed
Stalls that occur with G-forces being applied
Accelerated stalls
Maneuvering speed
Va
Force =
Mass X acceleration
Turning tendencies
Torque
Gyroscopic Precession
Asymmetrical thrust
Spiraling slipstream
Example of torque
Propeller rotates clockwise causing torque which tends to rotate the airplane counterclockwise about the longitudinal axis
Gyroscopic precession
Bike tire example
Asymmetrical thrust (P-factor)
More thrust on the right resulting in left yaw
Spiraling slipstream
Slipstream from propeller wraps around fuselage and hits left side of vertical fin (causes nose to yaw left)
Any aircraft surface that interferes with the smooth flow of air around an airplane
Parasite drag
Three types of parasite drag
Interference drag
Form drag
Skin friction drag
Produced by the shape of the object moving through the air
Form drag
Interaction of varied currents that flow over an airplane and mix together
Interference drag
Roughness of airplane surfaces
Skin friction drag
Drag created by the production of lift
Induced drag
Total drag =
Parasite + Induced
Distance aircraft will travel forward, without power, in relation to altitude loss
Glide ratio
Angle between glide path and horizon
Glide angle
Phenomenon of less induced drag close to the ground
Ground effect (pocket of air)
Causes and airplane to turn
Horizontal component of lift
Three axes of rotation
Longitudinal axis (ailerons)
Lateral axis (Elevators)
Vertical axis (rudder)
Adverse yaw
In a turn, outside wing produces more lift, causing yaw toward the outside of turn
Airframe, engines, and all items of operating equipment that have fixed locations and are permanently installed in the aircraft
Standard empty weight
Weight of the pilot, passengers, baggage, usable fuel, and drainable fuel
Useful load
Total weight of loaded aircraft, includes all fuel
Maximum ramp weight
Maximum allowable weight for takeoff
Maximum takeoff weight
AVGAS weight
6lbs/Gal
Aviation Oil weight
7.5lbs/Gal
A point along the wing chord line where lift is considered to be concentrated.
Center of Pressure (commonly called center of lift)
Explain ground effect
Interference of the surface of the earth with the airflow patterns about the aircraft in flight
Occurs when both wings are stalled and there is a yawing moment due to uncoordinated flight.
Spin
A center-seeking force directed inward toward the center of rotation
Centripetal force
How is centripetal force created?
Horizontal component of lift in turning flight
Explain centrifugal force
Pulling G's (force that pushes you into your seat)
Centrifugal force less that horizontal component of lift
Slipping turn
Centrifugal force more than horizontal lift
Skidding turn
Turning flight causes two additional forces to occur
Adverse yaw and overbanking
Stability
Aircraft's ability to resist change