1 - aerodynamics

four forces of flight

lift, weight, thrust, drag

parasite drag

the resistance of the air produced by any part of the airplane that does not produce lift

parasite drag

is proportional to the square of airspeed

form drag

the frontal area of the airplane exposed to the airstream

skin friction drag

caused by air passing over the surface

rough and dirty

skin friction drag increases if

interference drag

caused by interference of the airflow between adjacent parts of the airplane

induced drag

a by product of greater AOA (lift)

relative wind

the direction of the airflow produced by an object moving through the air

chord line

line from leading edge to trailing edge

angle of attack

the angle between the wing chord line and the relative wind

critical angle of attack

angle of attack at which a wing will stall

stall

occurs when the critical angle of attack is exceeded

horizontal component of lift

is what will make the airplane turn

pitch

movement around the lateral axis

elevator

controls pitch

roll

movement around the longitudinal axis

ailerons

control roll

yaw

movement around the vertical axis

rudder

controls yaw

flaps

high lift/high drag device

maneuverable

an aircraft that readily permits changes in pitch, roll, yaw, and direction while withstanding the resulting stresses imposed on it, is considered to be

controllability

the capability of an aircraft to respond to the pilot's inputs, especially with regard to flight path and attitude

stability

the tendency of an aircraft to develop forces which restore it to its original condition, when disturbed from a condition of steady flight

static stability

the initial tendency that the airplane displays after its equilibrium is disturbed

positive static stability

goes back to original condition

neutral static condition

stays at its new condition

negative static condition

moves away from original condition

dynamic stability

the overall tendency that the airplane displays after its equilibrium is disturbed

positive dynamic oscillatory longitudinal stability

pitch stability about the lateral axis

load factor

the ratio of the aerodynamic load on the airplanes wings (lift) to the actual weight of the aircraft and its contents

determining load on wing structure

multiply the airplanes weight by the number of G’s

2

how many G's are required to maintain level flight at 60 degrees bank?

maneuvering speed (Va)

the speed which abrupt control movement may be applied without causing structural damage to the aircraft

ground effect

the ground interferes with the airflow patterns about the wing increasing pressure below the wing

ground effect reduces:

AOA, induced drag, required power, wingtip vortices, airspeed required for flight, down wash (airwad)

spins

occurs in a stalled state

wingtip vortices

spillage of air from the bottom to the top of the wing

turning tendencies

greatest at low airspeeds, high power setting and high AOA

torque

the clockwise rotation of the prop torque rolls the aircraft counterclockwise causing left bank

which turning tendency is based on newton's third law of action?

torque

spiraling slipstream

air from the propeller blade forces back in a spiraling clockwise direction around the fuselage and strikes the left side of the vertical stabilizer

gyroscopic precession

the result of the force applied to the propeller occurs 90 degrees later in the direction of rotation

p factor

the descending blade takes a bigger "bite" of air than the ascending blade

p factor

which turning tendency is also known as asymmetric propeller loading?

4

doubling airspeed increases kinetic energy how many times?